Apparatus and method for performing power correction in a wireless power transmission system

Abstract

To provide a wireless power receiver, a wireless power transmitter, and a method capable of elaborately detecting a foreign object by detecting power loss.SOLUTION: A wireless power transmitter 100 comprises: a power conversion unit 110 that transmits wireless power generated based on magnetic coupling in a power transmission stage to a wireless power receiver 200; and a communication / control unit 120 that receives a first receiving power packet and a second receiving power packet at a first operating point related to power calibration from the wireless power receiver that operates at the first operating point to configure a first power calibration curve on the basis of the first receiving power packet and the second receiving power packet at the first operating point, and receives the first receiving power packet and the second receiving power packet at a second operating point related to power calibration from the wireless power receiver that operates at the second operating point to configure a second power calibration curve on the basis of the first receiving power packet and the second receiving power packet at the second operating point.SELECTED DRAWING: Figure 4c

Description

[Technical Field]

[0001] The present invention relates to wireless charging, and more particularly to an apparatus and method for performing power correction in a wireless power transmission system. [Background technology]

[0002] Wireless power transmission technology is a technology that wirelessly transmits power between a power source and an electronic device. For example, wireless power transmission technology allows wireless devices such as smartphones and tablets to be charged simply by placing them on a wireless charging pad, providing greater mobility, convenience, and safety than existing wired charging environments that use wired charging connectors. In addition to wireless charging for wireless devices, wireless power transmission technology is gaining attention as a potential alternative to existing wired power transmission environments in a variety of fields, including electric vehicles, various wearable devices such as Bluetooth earphones and 3D glasses, home appliances, furniture, underground facilities, buildings, medical devices, robots, and leisure activities.

[0003] The wireless power transmission method is also called a contactless power transmission method, a no-point-of-contact power transmission method, or a wireless charging method. A wireless power transmission system may include a wireless power transmitter that supplies electric energy to the wireless power transmission method, and a wireless power receiver that receives the electric energy wirelessly from the wireless power transmitter and supplies power to a power receiver such as a battery cell.

[0004] There are various wireless power transmission technologies, including those that transmit power through magnetic coupling, radio frequency (RF), microwave, and ultrasonic waves. Furthermore, magnetic coupling-based methods are classified into magnetic induction and magnetic resonance. Magnetic induction transmits energy by using a current induced in a receiving coil by a magnetic field generated in a battery cell in the transmitting coil through electromagnetic coupling between the transmitting and receiving coils. Magnetic resonance is similar to magnetic induction in that it uses a magnetic field. However, magnetic resonance differs from magnetic induction in that it transmits energy by generating resonance when a specific resonant frequency is applied to the transmitting and receiving coils, resulting in the concentration of magnetic fields at both ends of the transmitting and receiving coils.

[0005] Although a wireless power transmitter and a wireless power receiver are composed of numerous internal circuit components and are independent of each other, wireless power transmission occurs between them due to magnetic coupling. Therefore, the wireless power transmitter and the wireless power receiver constitute a single wireless power transmission system. However, errors can occur between the transmitted power and the received power due to changes in magnetic coupling caused by the actual usage environment of the Tx and Rx (such as the magnitude, frequency, and duty cycle of the signal applied to the wireless power transmission system, and the distance / positional alignment between the Tx and Rx). These errors can be an obstacle to precise foreign object detection.

[0006] Therefore, there is a need for a method for correcting the transmission power and reception power in accordance with the inherent characteristics of the wireless power transmission system and changes in the actual usage environment, and for performing more sophisticated FOD based on the corrected transmission power and reception power. Summary of the Invention [Problem to be solved by the invention]

[0007] SUMMARY OF THE INVENTION A technical object of the present invention is to provide an apparatus and method for performing power correction in a wireless power transmission system.

[0008] Another technical object of the present invention is to provide an apparatus and method for adaptively correcting power in response to load changes and performing foreign object detection.

[0009] Another technical object of the present invention is to provide an apparatus and method for adaptively correcting power in response to changes in magnetic coupling between a wireless power transmitting device and a wireless power receiving device and for detecting foreign objects.

[0010] The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0011] A wireless power transmitting device according to one embodiment of the present invention includes a power conversion unit configured to transmit wireless power generated based on magnetic coupling to a wireless power receiving device in a power transfer phase, and a communication / control unit configured to receive first and second received power packets related to power correction from the wireless power receiving device, configure a first power correction curve based on the first and second received power packets, and receive third and fourth received power packets related to power correction from the wireless power receiving device, configure a second power correction curve based on the third and fourth received power packets.

[0012] A wireless power receiving device according to one embodiment of the present invention includes a power conversion unit configured to receive wireless power generated based on magnetic coupling from a wireless power transmitting device in a power transfer phase, and a communication / control unit configured to transmit a first received power packet and a second received power packet related to power correction to the wireless power transmitting device in a first operating mode, and to transmit a third received power packet and a fourth received power packet related to power correction to the wireless power transmitting device in a second operating mode.

[0013] A wireless power transmitting apparatus according to an embodiment of the present invention includes a power conversion unit configured to transmit wireless power generated based on magnetic coupling to a wireless power receiving apparatus in a power transfer phase, and a communication / control unit configured to receive a first received power packet at a first operating point and a second received power packet at the first operating point related to power correction from the wireless power receiving apparatus operating at a first operating point, and to configure a first power correction curve based on the first received power packet at the first operating point and the second received power packet at the first operating point, and to receive a first received power packet at a second operating point and a second received power packet at a second operating point related to power correction from the wireless power receiving apparatus operating at a second operating point, and to configure a second power correction curve based on the first received power packet at the second operating point and the second received power packet at the second operating point.

[0014] A wireless power receiving device according to one embodiment of the present invention includes a power conversion unit configured to receive wireless power generated based on magnetic coupling from a wireless power transmitting device in a power transfer phase, and a communication / control unit that operates at a first operating point to transmit a first received power packet at the first operating point and a second received power packet at the first operating point related to power correction to the wireless power transmitting device, and that transmits a first received power packet at the second operating point and a second received power packet at the second operating point related to power correction to the wireless power transmitting device when the operating point is changed from the first operating point to a second operating point.

[0015] Other details of the invention are included in the detailed description and drawings. [Effects of the Invention]

[0016] It adaptively responds to the newly changed wireless charging environment to correct the transmission power and reception power, and based on this, detects power loss, enabling sophisticated foreign object detection.

[0017] The effects of the present invention are not limited to the above-mentioned examples, and more diverse effects are included within the present specification. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a block diagram of a wireless power system 10 according to an embodiment. [Figure 2] FIG. 1 is a block diagram of a wireless power system 10 according to another embodiment. [Figure 3a] 1 illustrates various examples of electronic devices in which a wireless power transmission system may be implemented. [Figure 3b] 1 shows an example of WPC NDEF in a wireless power transmission system. [Figure 4a]FIG. 10 is a block diagram of a wireless power transmission system according to another embodiment. [Figure 4b] 1 illustrates an example of a Bluetooth communication architecture to which an embodiment of the present disclosure can be applied. [Figure 4c] 1 is a block diagram illustrating a wireless power transmission system using BLE communication according to an example. [Figure 4d] FIG. 10 is a block diagram illustrating a wireless power transmission system using BLE communication according to another example. [Figure 5] FIG. 10 is a state transition diagram for explaining a wireless power transmission procedure. [Figure 6] 1 illustrates a power control method according to an embodiment. [Figure 7] FIG. 10 is a block diagram of a wireless power transmission device according to another embodiment. [Figure 8] 10 shows a wireless power receiving device according to another embodiment. [Figure 9] 1 illustrates a communication frame structure according to one embodiment. [Figure 10] 10 is a diagram illustrating a structure of a sync pattern according to an embodiment. [Figure 11] 1 illustrates an operation state of a wireless power transmitter and a wireless power receiver in a shared mode according to an embodiment. [Figure 12] FIG. 10 is a block diagram illustrating a wireless charging certificate format according to an embodiment. [Figure 13] 10 illustrates a performance packet structure of a wireless power transmission device according to an embodiment. [Figure 14] 10 illustrates a configuration packet structure of a wireless power receiving apparatus according to an embodiment. [Figure 15] 1 illustrates an application-level data stream between a wireless power transmitting device and a receiving device according to an example. [Figure 16] 1 is a flow diagram illustrating a method for performing power correction and foreign object detection according to one embodiment. [Figure 17] 10 illustrates a format of a received power packet according to an example. [Figure 18] 1 is a diagram illustrating a power transmission characteristic or correction curve according to an embodiment. [Figure 19] 10 is a diagram illustrating a power transmission characteristic or correction curve according to another embodiment. [Figure 20] 1 is a flowchart illustrating a foreign object detection method according to an embodiment. [Figure 21] 10 is a flow chart illustrating a method for performing power correction and foreign object detection according to another embodiment. [Figure 22] 1 is a flow chart illustrating a power correction method based on coupling change according to an embodiment. [Figure 23] 10 is a flow chart illustrating a power correction method based on coupling change according to another embodiment. [Figure 24] 10 illustrates a format of a re-PING packet according to an example. [Figure 25] 1 is a flow diagram illustrating a method for performing power correction and foreign object detection according to one embodiment. [Figure 26] 1 is a flow chart illustrating a method for correcting power based on foreign object insertion or coupling change according to an embodiment. [Figure 27] 10 is a flowchart illustrating a power correction method based on coupling change or foreign object insertion according to another embodiment. [Figure 28] 10 is a power transmission characteristic or correction curve according to another embodiment of the present invention. [Figure 29] 10 is a power transmission characteristic or correction curve according to another embodiment of the present invention. [Figure 30] 10 is a power transmission characteristic or correction curve according to another embodiment of the present invention. [Figure 31] 10 is a graph showing an initial power correction curve. [Figure 32] 10 is a graph showing an expanded power correction curve. [Figure 33] A method for performing foreign object detection when Pfo is equal to or greater than a threshold value is shown. [Figure 34] 10 is a graph illustrating a method for modeling a correction curve according to an example. [Figure 35] 10 is a graph showing a method for modeling a correction curve according to another example. [Figure 36]10 is a diagram illustrating a method for constructing an initial correction curve according to an embodiment; [Figure 37] The correction curve is shown with the y-intercept of the initial correction curve updated. [Figure 38] The slope and y-intercept of the initial correction curve are updated to show the correction curve. DETAILED DESCRIPTION OF THE INVENTION

[0019] As used herein, "A or B" can mean "A only," "B only," or "both A and B." Alternatively, as used herein, "A or B" can be interpreted as "A and / or B." For example, as used herein, "A, B, or C" can mean "A only," "B only," "C only," or "any combination of A, B, and C."

[0020] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "A and / or B." Therefore, "A / B" can mean "A only," "B only," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0021] As used herein, "at least one of A and B" can mean "A only," "B only," or "both A and B." Furthermore, as used herein, the expressions "at least one of A or B" and "at least one of A and / or B" can be interpreted as "at least one of A and B."

[0022] Furthermore, in this specification, "at least one of A, B and C" can mean "A only," "B only," "C only," or "any combination of A, B and C." Furthermore, "at least one of A, B or C" or "at least one of A, B and / or C" can mean "at least one of A, B and C."

[0023] Furthermore, parentheses used herein may mean "for example." Specifically, when "control information (PDCCH)" is used, "PDCCH" is proposed as an example of "control information." In other words, "control information" in this specification is not limited to "PDCCH," and "PDDCH" is proposed as an example of "control information." Furthermore, when "control information (i.e., PDCCH)" is used, "PDCCH" is proposed as an example of "control information."

[0024] In this specification, technical features individually described in one drawing may be implemented individually or simultaneously. Hereinafter, the term "wireless power" refers to any form of energy associated with an electric field, magnetic field, electromagnetic field, etc., transmitted from a wireless power transmitter to a wireless power receiver without the use of a physical electromagnetic conductor. Wireless power, also referred to as a wireless power signal, may refer to an oscillating magnetic flux enclosed by a primary coil and a secondary coil. For example, power conversion in a system for wirelessly charging devices including mobile phones, cordless phones, iPods, MP3 players, headsets, etc. is described herein. Generally, basic principles of wireless power transmission include, for example, methods of transmitting power via magnetic coupling, methods of transmitting power via radio frequency (RF), methods of transmitting power via microwave, and methods of transmitting power via ultrasound.

[0025] FIG. 1 is a block diagram of a wireless power system 10 according to one embodiment.

[0026] Referring to FIG. 1, a wireless power system 10 includes a wireless power transmitting device 100 and a wireless power receiving device 200.

[0027] The wireless power transmitting apparatus 100 receives power from an external power source S to generate a magnetic field, and the wireless power receiving apparatus 200 receives power wirelessly by generating a current using the generated magnetic field.

[0028] In addition, in the wireless power system 10, the wireless power transmitter 100 and the wireless power receiver 200 can transmit and receive various information required for wireless power transmission. Herein, communication between the wireless power transmitter 100 and the wireless power receiver 200 can be performed by either in-band communication using a magnetic field used for wireless power transmission or out-band communication using a separate communication carrier. Out-band communication is also called out-of-band communication. Hereinafter, the term out-band communication will be used. Examples of out-band communication include NFC, Bluetooth, and Bluetooth low energy (BLE).

[0029] Here, the wireless power transmission apparatus 100 can be provided as a fixed type or a mobile type. Examples of the fixed type include a type embedded in a ceiling, wall, or furniture such as a table indoors, a type implanted in an outdoor parking lot, bus stop, or subway station, or a type installed in a transportation means such as a vehicle or train. The mobile type wireless power transmission apparatus 100 can be embodied as a part of another device, such as a mobile device having a movable weight and size, or a notebook computer cover.

[0030] Furthermore, the wireless power receiving apparatus 200 should be construed as a comprehensive concept including various electronic devices equipped with a battery and various home appliances that are powered by wireless power supply instead of a power cable. Representative examples of the wireless power receiving apparatus 200 include a portable terminal, a cellular phone, a smart phone, a personal digital assistant (PDA), a portable media player (PMP), a Wibro terminal, a tablet, a phablet, a notebook, a digital camera, a navigation terminal, a television, an electric vehicle (EV), etc.

[0031] FIG. 2 is a block diagram of a wireless power system 10 according to another embodiment.

[0032] 2, the wireless power system 10 includes one or more wireless power receiving devices 200. While Fig. 1 illustrates that the wireless power transmitting device 100 and the wireless power receiving device 200 exchange power one-to-one, it is also possible for one wireless power transmitting device 100 to transmit power to multiple wireless power receiving devices 200-1, 200-2, ..., 200-M as shown in Fig. 2. In particular, when wireless power transmission is performed using a magnetic resonance method, one wireless power transmitting device 100 can simultaneously transmit power to multiple wireless power receiving devices 200-1, 200-2, ..., 200-M by applying a simultaneous transmission method or a time division transmission method.

[0033] 1 illustrates a method in which the wireless power transmitting apparatus 100 directly transmits power to the wireless power receiving apparatus 200, a separate wireless power transceiver such as a relay or repeater may be provided between the wireless power transmitting apparatus 100 and the wireless power receiving apparatus 200 to increase the wireless power transmission distance. In this case, power may be transmitted from the wireless power transmitting apparatus 100 to the wireless power transceiver, and the wireless power transceiver may transmit power again to the wireless power receiving apparatus 200.

[0034] Hereinafter, the terms "wireless power receiver," "power receiver," and "receiver" referred to in this specification refer to the wireless power receiving apparatus 200. Also, the terms "wireless power transmitter," "power transmitter," and "transmitter" referred to in this specification refer to the wireless power receiving and transmitting apparatus 100.

[0035] FIG. 3a shows various examples of electronic devices in which the wireless power transmission system can be implemented.

[0036] Figure 3a shows electronic devices classified according to the amount of power transmitted and received in a wireless power transmission system. Referring to Figure 3a, a low-power (approximately 5W or less or approximately 20W or less) wireless charging method can be applied to wearable devices such as smart watches, smart glasses, head-mounted displays (HMDs), and smart rings, as well as mobile (or portable) electronic devices such as earphones, remote controls, smartphones, PDAs, and tablet PCs.

[0037] A medium-power (approximately 50W or less or approximately 200W or less) wireless charging method can be applied to small and medium-sized home appliances such as notebooks, robot vacuum cleaners, TVs, audio equipment, vacuum cleaners, and monitors. A high-power (approximately 2kW or less or approximately 22kW or less) wireless charging method can be applied to kitchen appliances such as blenders, microwave ovens, and electric rice cookers, and personal transportation devices (or electronic devices / transportation means) such as wheelchairs, electric scooters, electric bicycles, and electric cars.

[0038] The electronic devices / mobile means described above (or shown in FIG. 1) may each include a wireless power receiver, which will be described later. Therefore, the electronic devices / mobile means described above can be charged by receiving power wirelessly from a wireless power transmitter.

[0039] Although the following description focuses on a mobile device to which a wireless power charging method is applied, this is merely an example, and the wireless charging method according to the present specification can be applied to the various electronic devices described above.

[0040] Standards for wireless power transmission include the wireless power consortium (WPC), the air fuel alliance (AFA), and the power matters alliance (PMA).

[0041] The WPC standard defines a baseline power profile (BPP) and an extended power profile (EPP), where BPP is for wireless power transmitters and receivers that support 5W power transmission, and EPP is for wireless power transmitters and receivers that support power transmission in the range greater than 5W and less than 30W.

[0042] Each standard covers a variety of wireless power transmitters and receivers using different power levels, and these may be classified into different power classes or categories.

[0043] For example, the WPC classifies wireless power transmitters and receivers into power classes (PC-1, PC0, PC1, and PC2) and provides standard documents for each PC. The PC-1 standard relates to wireless power transmitters and receivers that provide guaranteed power of less than 5W. PC-1 applications include wearable devices such as smart watches.

[0044] The PC0 standard relates to wireless power transmitters and receivers that provide 5W of guaranteed power. The PC0 standard includes EPP, which provides guaranteed power up to 30W. In-band (IB) communication is the mandatory communication protocol for PC0, and out-band (OB) communication, which is used as an optional backup channel, can also be used. A wireless power receiver can identify whether it supports OB by setting the OB flag in a configuration packet. A wireless power transmitter that supports OB can enter the OB handover phase by transmitting a bit pattern for OB handover in response to the configuration packet. The response to the configuration packet is NAK, ND, or a newly defined 8-bit pattern. PC0 applications include smartphones.

[0045] The PC1 standard relates to wireless power transmitters and receivers that provide guaranteed power of 30W to 150W. OB is the required communication channel for PC1, and IB is used for initialization and link establishment to OB. A wireless power transmitter can enter the OB handover phase using a bit pattern for OB handover in response to a configuration packet. PC1 applications include laptops and power tools.

[0046] The PC2 standard relates to wireless power transmitters and receivers that provide guaranteed power between 200W and 2kW, and its applications include kitchen appliances.

[0047] In this way, PCs can be distinguished by power levels, and whether or not to support same-PC compatibility is optional or mandatory. Here, same-PC compatibility means that power can be transmitted and received between the same PCs. For example, if a wireless power transmitting apparatus that is PCx can charge a wireless power receiving apparatus having the same PCx, it can be determined that same-PC compatibility is maintained. Similarly, different-PC compatibility can also be supported. Here, different-PC compatibility means that power can be transmitted and received between different PCs. For example, if a wireless power transmitting apparatus that is PCx can charge a wireless power receiving apparatus having PCy, it can be determined that different-PC compatibility is maintained.

[0048] Supporting inter-PC compatibility is a very important issue in terms of user experience and infrastructure construction. However, maintaining inter-PC compatibility poses a number of technical challenges, including the following:

[0049] In the case of compatibility between the same PCs, for example, a laptop-charging type wireless power receiving device that can be stably charged only when power is continuously transmitted has a problem when receiving a stable supply of power from a power tool-type wireless power transmitting device that transmits power discontinuously, even though it is a wireless power transmitting device for the same PC. Also, in the case of compatibility between different PCs, for example, a wireless power transmitting device with a minimum guaranteed power of 200 W may be damaged by overvoltage when transmitting power to a wireless power receiving device with a maximum guaranteed power of 5 W. As a result, it is difficult to determine PCs as an index / standard representing / indicating compatibility.

[0050] The wireless power transmitting and receiving device can provide a highly convenient user experience and interface (UX / UI). That is, a smart wireless charging service can be provided. The smart wireless charging service can be implemented based on the UX / UI of a smartphone that includes the wireless power transmitting device. For such applications, the interface between the smartphone's processor and the wireless charging receiving device allows for "drop and play" bidirectional communication between the wireless power transmitting device and the receiving device.

[0051] As an example, a user may experience a smart wireless charging service at a hotel. When the user enters a hotel room and places their smartphone on the room's wireless charger, the wireless charger transmits wireless power to the smartphone, which then receives the wireless power. During this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smartphone detects that it is located on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state in which it asks the user for consent (opt-in) to additional features. To this end, the smartphone may display a message on the screen, with or without an alarm. An example of the message may include text such as "Welcome to ### hotel. Select 'Yes' to activate smart charging functions: Yes | No Thanks." The smartphone receives the user's input of selecting Yes or No Thanks and executes the next step selected by the user. If Yes is selected, the smartphone transmits the corresponding information to the wireless charger. Then, the smartphone and the wireless charger perform the smart charging function together.

[0052] The smart wireless charging service may also include receiving auto-filled WiFi credentials. For example, the wireless charger sends WiFi credentials to a smartphone, and the smartphone automatically fills in the WiFi credentials received from the wireless charger by running an appropriate APP.

[0053] The smart wireless charging service may also include running a hotel application that offers hotel promotions or obtains remote check-in / check-out and contact information.

[0054] As another example, a user can experience a smart wireless charging service in a vehicle. When a user gets into a vehicle and places a smartphone on a wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smartphone detects that it is located on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state in which it queries the user for identity verification.

[0055] In this state, the smartphone automatically connects to the vehicle via Wi-Fi and / or Bluetooth. The smartphone can display a message on the screen, with or without an alarm. An example of a message could include text such as "Welcome to your car. Select 'Yes' to synchronize device with in-car controls: Yes | No Thanks." The smartphone receives user input selecting Yes or No Thanks and executes the next step selected by the user. If Yes is selected, the smartphone sends the corresponding information to the wireless charger. The smartphone and wireless charger can then run the in-vehicle application / display software to perform smart in-vehicle control functions together. The user can enjoy desired music and view the correct map location. The in-vehicle application / display software can include the ability to provide synchronized access for passersby.

[0056] As another example, a user can experience smart wireless charging within their home. When a user enters a room and places their smartphone on a proposed wireless charger, the wireless charger transmits wireless power to the smartphone, which then receives the wireless power. During this process, the wireless charger transmits information about the smart wireless charging service to the smartphone. When the smartphone detects that it is located on the wireless charger, detects the reception of wireless power, or receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state in which it asks the user for consent (opt-in) to additional features. To do this, the smartphone can display a message on the screen with or without an alarm. An example of the message could include text such as, "Hi xxx, Would you like to activate night mode and secure the building?: Yes | No Thanks." The smartphone receives the user's input, selecting Yes or No Thanks, and then performs the next step selected by the user. If Yes is selected, the smartphone transmits the corresponding information to the wireless charger. The smartphone and wireless charger can at least recognize the user's patterns and prompt the user to close doors and windows, turn off the power, or set an alarm.

[0057] Hereinafter, a new term "profile" is defined as an index / criteria representing / indicating compatibility. That is, it can be interpreted that compatibility is maintained between wireless power transceivers having the same "profile" and stable power transmission / reception is possible, while power transmission / reception is not possible between wireless power transceivers having different "profiles." A profile can be defined according to compatibility and / or application, regardless of (or independently of) the power class.

[0058] The profiles can be broadly divided into three categories: i) mobile and computer, ii) power tools, and iii) kitchen.

[0059] Alternatively, the profiles can be broadly divided into four categories: i) mobile, ii) power tools, iii) kitchen, and iv) wearable.

[0060] In the case of the 'Mobile' profile, the PC can be defined as PC0 and / or PC1, the communication protocol / method can be IB and OB, and the operating frequency can be defined as 87 to 205 kHz. Examples of applications include smartphones and laptops.

[0061] In the case of the 'power tool' profile, the PC can be defined as PC1, the communication protocol / method as IB, and the operating frequency as 87 to 145 kHz, and an example of an application can be a power tool.

[0062] In the case of the 'Kitchen' profile, the PC can be defined as PC2, the communication protocol / method as NFC-based, and the operating frequency as less than 100 kHz, and examples of applications include kitchen / home appliances.

[0063] For the power tool and kitchen profiles, NFC communication can be used between the wireless power transmitter and receiver. The wireless power transmitter and receiver can mutually identify themselves as NFC devices by exchanging WPC NDEF (NFC Data Exchange Profile Format).

[0064] FIG. 3b shows an example of WPC NDEF in a wireless power transmission system.

[0065] 3b, the WPC NDEF may include, for example, an application profile field (e.g., 1B), a version field (e.g., 1B), and profile specific data (e.g., 1B). The application profile field indicates whether the corresponding device is i) a mobile and computer, ii) a power tool, or iii) a kitchen. The upper nibble of the version field indicates the major version, and the lower nibble indicates the minor version. The profile specific data defines the content for the kitchen.

[0066] In the case of the 'Wearable' profile, the PC can be defined as PC-1, the communication protocol / method as IB, and the operating frequency as 87 to 205 kHz. An example of an application could be a wearable device worn on the user's body.

[0067] Maintaining compatibility within the same profile is a requirement, while maintaining compatibility between different profiles is an option.

[0068] The above-mentioned profiles (mobile profile, power tool profile, kitchen profile, and wearable profile) can be generalized and expressed as profiles 1 to n, and new profiles can be added / replaced depending on the WPC standard and embodiment.

[0069] When a profile is defined in this way, a wireless power transmitter selectively transmits power only to a wireless power receiver having the same profile as itself, thereby enabling more stable power transmission. In addition, the burden on the wireless power transmitter is reduced, and the wireless power receiver is prevented from attempting to transmit power to an incompatible wireless power receiver, thereby reducing the risk of damage to the wireless power receiver.

[0070] PC1 in the 'Mobile' profile can be defined by borrowing optional extensions such as OB based on PC0, and in the case of the 'Power Tool' profile, PC1 'Mobile' profile can be defined as a simply modified version. Also, up until now, profiles have been defined with the aim of maintaining compatibility between the same profiles, but in the future, technology may develop toward maintaining compatibility between different profiles. A wireless power transmitting device or a wireless power receiving device can notify its profile to the other device through various methods.

[0071] The AFA standard refers to a wireless power transmitting device as a PTU (power transmitting circuit) and a wireless power receiving device as a PRU (power receiving circuit). PTUs are classified into multiple classes as shown in Table 1, and PRUs are classified into multiple categories as shown in Table 2.

[0072] [Table 1]

[0073] [Table 2]

[0074] As shown in Table 1, the maximum output power capability of a Class n PTU is determined by the P TX_IN_MAX Greater than or equal to the value. A PRU cannot draw more power than specified for its category.

[0075] FIG. 4a is a block diagram of a wireless power transmission system according to another embodiment.

[0076] Referring to FIG. 4a, the wireless power transmission system 10 includes a mobile device 450 that wirelessly receives power and a base station 400 that wirelessly transmits power.

[0077] The base station 400 is a device that provides inductive power or resonant power and can include at least one wireless power transmitter 100 and a system circuit 405. The wireless power transmitter 100 can transmit and control the inductive power or resonant power. The wireless power transmitter 100 can include a power conversion circuit 110 that converts electrical energy into a power signal by generating a magnetic field through primary coil(s), and a communications & control circuit 120 that communicates with the wireless power receiver 200 and controls power transfer to transfer power at an appropriate level. The system circuit 405 can perform input power provisioning, control of multiple wireless power transmitters, and other operational control of the base station 400, such as user interface control.

[0078] The primary coil can generate an electromagnetic field using AC power (or voltage or current). The primary coil can generate a magnetic field of a specific frequency by receiving AC power (or voltage or current) of a specific frequency output from the power conversion circuit 110. The magnetic field can be generated in a non-radiative or radiative manner, and the wireless power receiving device 200 receives the magnetic field and generates a current. That is, the primary coil transmits power wirelessly.

[0079] In magnetic induction, the primary and secondary coils can have any suitable form, such as copper wire wound around a highly permeable material such as ferrite or amorphous metal. The primary coil is also called the transmitting coil, primary core, primary winding, or primary loop antenna. The secondary coil is also called the receiving coil, secondary core, secondary winding, secondary loop antenna, or pickup antenna.

[0080] When using the magnetic resonance method, the primary coil and the secondary coil may be provided in the form of a primary resonant antenna and a secondary resonant antenna, respectively. The resonant antenna may have a resonant structure including a coil and a capacitor. In this case, the resonant frequency of the resonant antenna is determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil may be in the form of a loop. Also, a core may be disposed inside the loop. The core may include a physical core such as a ferrite core or an air core.

[0081] Energy transmission between the primary and secondary resonant antennas can occur through magnetic field resonance. The resonance phenomenon refers to a phenomenon in which, when a near field corresponding to a resonant frequency is generated in one resonant antenna and another resonant antenna is located nearby, the two resonant antennas are coupled to each other, resulting in highly efficient energy transfer between the resonant antennas. When a magnetic field corresponding to the resonant frequency is generated between the primary and secondary resonant antennas, the primary and secondary resonant antennas resonate with each other. As a result, the magnetic field generated by the primary resonant antenna is directed toward the secondary resonant antenna with higher efficiency than when the magnetic field is generally emitted into free space. Therefore, energy can be transferred from the primary resonant antenna to the secondary resonant antenna with high efficiency. The magnetic induction method can be implemented in a manner similar to the magnetic resonance method, but the frequency of the magnetic field does not need to be the resonant frequency. Instead, the magnetic induction method requires matching between the loops constituting the primary and secondary coils, and the distance between the loops must be fairly close.

[0082] Although not shown in the drawings, the wireless power transmission apparatus 100 may further include a communication antenna. The communication antenna can transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna can transmit and receive communication signals of Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0083] The communication / control circuit 120 can transmit and receive information to and from the wireless power receiving apparatus 200. The communication / control circuit 120 can include at least one of an IB communication module or an OB communication module.

[0084] The IB communication module can transmit and receive information using magnetic waves centered on a specific frequency. For example, the communication / control circuit 120 can perform in-band communication by including communication information in the operating frequency of wireless power transmission and transmitting it through the primary coil, or by receiving the operating frequency containing information through the primary coil. Information can be included in magnetic waves or interpreted using modulation methods such as binary phase shift keying (BPSK), frequency shift keying (FSK), or amplitude shift keying (ASK), and coding methods such as Manchester coding or non-return-to-zero level (NZR-L) coding. Using this IB communication, the communication / control circuit 120 can transmit and receive information over distances of several meters at a data transmission rate of several kbps.

[0085] The OB communication module can also perform out-of-band communication via a communication antenna. For example, the communication / control circuit 120 can be provided in a short-range communication module. Examples of short-range communication modules include Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC communication modules.

[0086] The communication / control circuit 120 can control the overall operation of the wireless power transmission apparatus 100. The communication / control circuit 120 can perform calculations and processes of various information and control each component of the wireless power transmission apparatus 100.

[0087] The communication / control circuit 120 can be implemented as a computer or similar device using hardware, software, or a combination thereof. In terms of hardware, the communication / control circuit 120 can be implemented in the form of an electronic circuit that processes electrical signals and performs control functions, and in terms of software, it can be implemented in the form of a program that drives the hardware communication / control circuit 120.

[0088] The communication / control circuit 120 can control the transmission power by controlling an operating point. The controlled operating point may correspond to a combination of a frequency (or phase), a duty cycle, a duty ratio, and a voltage amplitude. The communication / control circuit 120 can control the transmission power by adjusting at least one of the frequency (or phase), the duty cycle, the duty ratio, and the voltage amplitude. Alternatively, the wireless power transmitter 100 can supply a constant power, and the wireless power receiver 200 can control the reception power by controlling the resonant frequency.

[0089] The mobile device 450 includes a wireless power receiver 200 that receives wireless power through a secondary coil and a load 455 that receives the power received by the wireless power receiver 200, stores the power, and supplies it to the device.

[0090] The wireless power receiving device 200 may include a power pickup circuit 210 and a communications & control circuit 220. The power pickup circuit 210 receives wireless power via a secondary coil and converts it into electrical energy. The power pickup circuit 210 rectifies an AC signal obtained via the secondary coil and converts it into a DC signal. The communications & control circuit 220 controls the transmission and reception of wireless power (power transmission and reception).

[0091] The secondary coil can receive wireless power transmitted from the wireless power transmitting apparatus 100. The secondary coil can receive power using a magnetic field generated in the primary coil. Here, if a specific frequency is a resonant frequency, a magnetic resonance phenomenon occurs between the primary coil and the secondary coil, allowing for more efficient power transmission.

[0092] Although not shown in FIG. 4a, the communication / control circuit 220 may further include a communication antenna. The communication antenna may transmit and receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna may transmit and receive communication signals using Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0093] The communication / control circuit 220 can transmit and receive information to and from the wireless power transmitting apparatus 100. The communication / control circuit 220 can include at least one of an IB communication module or an OB communication module.

[0094] The IB communication module can transmit and receive information using magnetic waves centered on a specific frequency. For example, the communication / control circuit 220 can perform IB communication by transmitting magnetic waves containing information through a secondary coil or receiving magnetic waves containing information through a secondary coil. Information can be included in or interpreted from magnetic waves using modulation methods such as binary phase shift keying (BPSK), frequency shift keying (FSK), or amplitude shift keying (ASK), and coding methods such as Manchester coding or non-return-to-zero level (NZR-L) coding. Using this IB communication, the communication / control circuit 220 can transmit and receive information over distances of several meters at a data transmission rate of several kbps.

[0095] The OB communication module can also perform out-of-band communication via a communication antenna. For example, the communication / control circuit 220 can be provided in a near-field communication module.

[0096] Examples of short-range communication modules include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC.

[0097] The communication / control circuit 220 may control the overall operation of the wireless power receiving apparatus 200. The communication / control circuit 220 may perform calculations and processes of various information and control each component of the wireless power receiving apparatus 200.

[0098] The communication / control circuit 220 can be implemented as a computer or similar device using hardware, software, or a combination thereof. In terms of hardware, the communication / control circuit 220 can be implemented in the form of an electronic circuit that processes electrical signals and performs control functions, and in terms of software, it can be implemented in the form of a program that drives the hardware communication / control circuit 220.

[0099] When the communication / control circuit 120 and the communication / control circuit 220 are Bluetooth or Bluetooth LE as an OB communication module or a short-range communication module, the communication / control circuit 120 and the communication / control circuit 220 can each be embodied and operated in a communication architecture such as that shown in FIG. 4b.

[0100] FIG. 4b illustrates an example of a Bluetooth communication architecture to which an embodiment according to the present disclosure can be applied.

[0101] Referring to Figure 4b, (a) of Figure 4b shows an example of a Bluetooth BR (Basic Rate) / EDR (Enhanced Data Rate) protocol stack that supports GATT, and (b) shows an example of a Bluetooth LE (Low Energy) protocol stack.

[0102] Specifically, as shown in (a) of FIG. 4b, the Bluetooth BR / EDR protocol stack may include an upper controller stack 460 and a lower host stack 470 based on the host controller interface (HCI) 18.

[0103] The host stack (or host module) 470 refers to a wireless transceiver module that receives 2.4 GHz Bluetooth signals and hardware for transmitting or receiving Bluetooth packets, and the controller stack 460 connects to a Bluetooth module and controls the Bluetooth module to perform operations.

[0104] The host stack 470 may include a BR / EDR PHY layer 12, a BR / EDR Baseband layer 14, and a Link Manager layer 16.

[0105] The BR / EDR PHY layer 12 is a layer for transmitting and receiving 2.4 GHz radio signals, and when using Gaussian Frequency Shift Keying (GFSK) modulation, can transmit data by hopping through 79 RF channels.

[0106] The BR / EDR Baseband layer 14 is responsible for transmitting digital signals, selecting a channel sequence that hops 1400 times per second, and transmitting a time slot of 625 us for each channel.

[0107] The link manager layer 16 controls the overall operation (link setup, control, security) of the Bluetooth connection using LMP (Link Manager Protocol).

[0108] The link manager layer 16 can perform the following functions:

[0109] -ACL / SCO logical transport, logical link setup and control.

[0110] Detach: Aborts the connection and notifies the other device of the reason for the abort.

[0111] -Power control and role switch.

[0112] -Performs security (authentication, pairing, encryption) functions.

[0113] The host controller interface layer 18 provides an interface between the host module and the controller module, allowing the host to provide commands and data to the controller, and the controller to provide events and data to the host.

[0114] The host stack (or host module) 20 includes a Logical Link Control and Adaptation Protocol (L2CAP) 21, an Attribute Protocol 22, a Generic Attribute Profile (GATT) 23, a Generic Access Profile (GAP) 24, and a BR / EDR Profile 25.

[0115] The Logical Link Control and Adaptation Protocol (L2CAP) 21 can provide a bidirectional channel for transmitting data in a specific protocol or profile.

[0116] The L2CAP21 can multiplex various protocols and profiles provided above Bluetooth.

[0117] Bluetooth BR / EDR L2CAP uses dynamic channels, supports protocol service multiplexer, retransmission, and streaming mode, and provides segmentation and reassembly, per-channel flow control, and error control.

[0118] The Generic Attribute Profile (GATT) 23 is operable as a protocol that describes how the attribute protocol 22 is used when configuring a service. For example, the Generic Attribute Profile 23 is operable to define how ATT attributes are grouped together in a service and to describe characteristics associated with a service.

[0119] Thus, the General Attribute Profile 23 and the Attribute Protocol (ATT) 22 can use features to describe the state and services of a device, how features relate to each other, and how they are used.

[0120] The attribute protocol 22 and the BR / EDR profile 25 define the service (profile) that uses Bluetooth BR / EDR and the application protocol for exchanging this data, and the Generic Access Profile (GAP) 24 defines device discovery, connection, and security levels.

[0121] As shown in FIG. 4b(b), the Bluetooth LE protocol stack includes a Controller stack 480 operable to handle the timing-critical radio device interface and a Host stack 490 operable to handle high level data.

[0122] First, the controller stack 480 can be implemented using a communications module that can include a Bluetooth radio, and a processor module that can include a processing device such as a microprocessor.

[0123] The host stack 490 may be implemented as part of an OS running on the processor module or as an instantiation of a package on the OS.

[0124] In some cases, the controller stack and the host stack may run or execute on the same processing device within a processor module.

[0125] The controller stack 480 includes a physical layer (PHY) 32, a link layer 34, and a host controller interface 36.

[0126] The physical layer (PHY, wireless transceiver module) 32 is a layer that transmits and receives 2.4 GHz wireless signals, and uses a frequency hopping technique consisting of Gaussian Frequency Shift Keying (GFSK) modulation and 40 RF channels.

[0127] The link layer 34, which is responsible for transmitting and receiving Bluetooth packets, performs advertising and scanning functions using three advertising channels, creates connections between devices, and provides the ability to exchange data packets of up to 257 bytes through 37 data channels.

[0128] The host stack may include a Generic Access Profile (GAP) 40, a Logical Link Control and Adaptation Protocol (L2CAP) 41, a Security Manager (SM) 42, an Attribute Protocol (ATT) 440, a Generic Attribute Profile (GATT) 44, a Generic Access Profile 25, and an LT Profile 46. However, the host stack 490 is not limited thereto and may include various protocols and profiles.

[0129] The host stack uses L2CAP to multiplex various protocols and profiles provided above Bluetooth.

[0130] First, the Logical Link Control and Adaptation Protocol (L2CAP) 41 can provide a single bidirectional channel for transmitting data in a specific protocol or profile.

[0131] The L2CAP 41 is operable to multiplex data between upper layer protocols, segment and reassemble packages, and manage multicast data transmissions.

[0132] Bluetooth LE basically uses three fixed channels (one for signaling CH, one for Security Manager, and one for Attribute protocol), and can also use dynamic channels as needed.

[0133] In contrast, BR / EDR (Basic Rate / Enhanced Data Rate) basically uses dynamic channels and supports protocol service multiplexer, retransmission, streaming mode, etc.

[0134] The Security Manager (SM) 42 is a protocol for authenticating devices and providing key distribution.

[0135] ATT (Attribute Protocol) 43 defines rules for accessing data of a remote device in a server-client structure. ATT has the following six message types: Request, Response, Command, Notification, Indication, and Confirmation.

[0136] (1) Request and Response Messages: A Request message is a message for requesting and transmitting specific information from a client device to a server device, and a Response message is a response message to a Request message and can be used to send from a server device to a client device.

[0137] (2) Command message: A message sent from a client device to a server device mainly to instruct a specific operation, and the server device does not send a response to the Command message to the client device.

[0138] (3) Notification message: A message sent from a server device to a client device to notify the server device of an event or the like, and the client device does not send a confirmation message for the Notification message to the server device.

[0139] (4) Indication and Confirm Messages: These are messages sent from the server device to the client device to notify the server of an event, etc. Unlike Notification messages, the client device sends a Confirm message to the server device in response to an Indication message.

[0140] In this specification, when a long data is requested in a GATT profile using the attribute protocol (ATT) 43, a value for the data length is transmitted so that the client can clearly know the data length, and the characteristic value can be transmitted from the server using a UUID.

[0141] The General Access Profile (GAP) 45 is a new layer implemented for Bluetooth LE technology, and is used to control how role selection and multi-profile operation for communication between Bluetooth LE devices occurs.

[0142] The general access profile 45 is mainly used in device discovery, connection creation, and security procedures, defines a method for providing information to a user, and defines the following attribute types:

[0143] (1) Service: A combination of data and related behaviors that defines the basic operation of a device.

[0144] (2) Include: Defines the relationship between services

[0145] (3) Characteristics: Data values ​​used in the service

[0146] (4) Behavior: A computer-readable format defined in the UUID (Universal Unique Identifier, value type)

[0147] The LE profile 46 is a profile that depends on GATT and is mainly applied to Bluetooth LE devices. Examples of the LE profile 46 include Battery, Time, FindMe, Proximity, and Time. Specific details of the GATT-based profiles are as follows:

[0148] (1) Battery: Battery information exchange method

[0149] (2) Time: Time information exchange method

[0150] (3) FindMe: Provides distance-based alarm services

[0151] (4) Proximity: Battery information exchange method

[0152] (5) Time: Time information exchange method

[0153] The Generic Attribute Profile (GATT) 44 is operable as a protocol that describes how the attribute protocol 43 is used when configuring a service. For example, the Generic Attribute Profile 44 is operable to define how ATT attributes are grouped together in a service and to describe characteristics associated with a service.

[0154] Thus, the General Attribute Profile 44 and the Attribute Protocol (ATT) 43 can use features to describe the state and services of a device, how features relate to each other, and how they are used.

[0155] The procedure of the Bluetooth Low Energy (BLE) technology will be briefly described below.

[0156] The BLE procedure can be divided into a device filtering procedure, an advertising procedure, a scanning procedure, a discovering procedure, a connecting procedure, etc.

[0157] Device Filtering Procedure

[0158] A device filtering procedure is a method for reducing the number of devices that respond to requests, instructions, announcements, etc. in a controller stack.

[0159] Since it is not necessary for all devices to respond to requests when they receive them, the controller stack can reduce the number of requests sent, thereby reducing power consumption in the BLE controller stack.

[0160] An advertising device or a scanning device can perform the device filtering procedure to restrict the devices that receive advertising packets, scan requests or connection requests.

[0161] Here, the advertising device refers to a device that transmits an advertising event, i.e., executes an advertisement, and may be expressed as an advertiser.

[0162] A scanning device refers to a device that performs scanning and sends a scan request.

[0163] In BLE, when a scanning device receives some advertising packets from an advertising device, the scanning device must send a scan request to the advertising device.

[0164] However, if a device filtering procedure is used and a scan request transmission is unnecessary, the scanning device can ignore the advertisement packets transmitted from the advertising device.

[0165] The device filtering procedure can also be used in the connection request process. If device filtering is used in the connection request process, the connection request is ignored, thereby eliminating the need to send a response to the connection request.

[0166] Advertising Procedure

[0167] The advertising device performs an advertising procedure to perform a non-directional broadcast to devices within the area.

[0168] Here, undirected advertising is advertising directed to all devices, not a broadcast directed to a specific device, and all devices can scan the advertising to request additional information or a connection.

[0169] In contrast, with directed advertising, only devices designated as receiving devices can scan the advertisement and request additional information or connection.

[0170] The advertisement procedure is used to establish a Bluetooth connection with a nearby initiating device.

[0171] Alternatively, the advertising procedure can be used to provide periodic broadcasts of user data to scanning devices listening on the advertising channel.

[0172] In the advertising procedure, all advertisements (or advertising events) are broadcast over the advertising physical channel.

[0173] The advertising device may receive a scan request from a listening device that is listening to obtain additional user data from the advertising device, and the advertising device may transmit a response to the scan request to the device that sent the scan request over the same advertising physical channel as the advertising physical channel over which the scan request was received.

[0174] The broadcast user data sent as part of the advertising packet is dynamic data, whereas the scan response data is generally static data.

[0175] An advertising device can receive a connection request from an initiating device on an advertising (broadcast) physical channel. If the advertising device uses a connectable advertising event and the initiating device is not filtered by the device filtering procedure, the advertising device stops advertising and enters connected mode. After entering connected mode, the advertising device can start advertising again.

[0176] Scanning Procedure

[0177] A device performing scanning, i.e., a scanning device, performs a scanning procedure to listen for non-directional broadcast of user data from advertising devices using advertising physical channels.

[0178] The scanning device transmits a scan request to the advertising device via an advertising physical channel to request additional data from the advertising device, and the advertising device transmits a scan response, which is a response to the scan request and includes the additional data requested by the scanning device, via the advertising physical channel.

[0179] The scanning procedure can be used while connecting with other BLE devices in a BLE piconet.

[0180] If the scanning device is in an initiator mode that can receive the broadcasted advertising event and initiate a connection request, the scanning device can initiate a Bluetooth connection with the advertising device by sending a connection request to the advertising device over the advertising physical channel.

[0181] When a scanning device sends a connection request to an advertising device, the scanning device ceases initiator mode scanning for additional broadcasts and enters connection mode.

[0182] Discovering Procedure

[0183] A device capable of Bluetooth communication (hereinafter referred to as a 'Bluetooth device') performs an advertisement procedure and a scanning procedure to discover nearby devices or to be discovered by other devices within a given area.

[0184] The discovering procedure is performed asymmetrically. A Bluetooth device that tries to find other devices in its vicinity is called a discovering device, and it listens to find devices that advertise scannable advertising events. A Bluetooth device that is discovered and available to other devices is called a discoverable device, and it actively broadcasts advertising events via a broadcast physical channel so that other devices can scan for them.

[0185] Both discovering and discoverable devices may already be connected to other Bluetooth devices in a piconet.

[0186] Connecting Procedure

[0187] The connection procedure is asymmetric; it requires that a particular Bluetooth device performs an advertising procedure while other Bluetooth devices perform a scanning procedure.

[0188] That is, the advertisement procedure can be objective, so that only one device responds to the advertisement. After receiving a connectable advertisement event from the advertisement device, a connection can be initiated by sending a connection request to the advertisement device via the advertisement (broadcast) physical channel.

[0189] Next, the operating states of the BLE technology, i.e., advertising state, scanning state, initiating state, and connection state, will be briefly described.

[0190] Advertising State

[0191] The link layer (LL) enters the advertising state at the command of the host (stack). When the link layer is in the advertising state, it sends an advertising PDU (Packet Data Circuit) at the advertising event.

[0192] Each advertising event consists of at least one advertising PDU, and the advertising PDU is transmitted via the advertising channel index used. The advertising event can be terminated when the advertising PDU is transmitted via the advertising channel index used, or the advertising event can be terminated early if the advertising device needs to make space for performing other functions.

[0193] Scanning State

[0194] The Link Layer enters the scanning state at the direction of the host (stack). In the scanning state, the Link Layer listens for advertising channel indexes.

[0195] There are two types of scanning states: passive scanning and active scanning, and each scanning type is determined by the host.

[0196] No separate time or advertising channel index is defined for performing scanning.

[0197] During the scanning state, the link layer listens for advertising channel indexes during the scan window duration. The scan interval is defined as the interval between the start of two consecutive scan windows.

[0198] The Link Layer shall listen for all scan intervals of the scan window as directed by the host if there are no scheduling conflicts. In each scan window, the Link Layer shall scan for other advertising channel indexes. The Link Layer shall use all available advertising channel indexes.

[0199] When passively scanning, the link layer can only receive packets and cannot send any packets.

[0200] When actively scanning, the link layer listens to the advertising device to request an advertising PDU and additional information related to the advertising device depending on the advertising PDU type.

[0201] Initiating State

[0202] The link layer enters the starting state at the command of the host (stack).

[0203] When the link hierarchy is in the start state, it listens for an advertising channel index.

[0204] During the start state, the link layer listens for advertising channel indexes during the scan window interval.

[0205] connection state

[0206] The link layer enters the connected state when the device executing the connection request, i.e., the initiating device, sends a CONNECT_REQ PDU to the advertising device or when the advertising device receives a CONNECT_REQ PDU from the initiating device.

[0207] A connection is considered to be created after entering the connected state. However, a connection does not necessarily have to be considered established at the time of entering the connected state. The only difference between a newly created connection and an already established connection is the link layer connection supervision timeout value.

[0208] When two devices are connected, they act in different roles.

[0209] A link layer that performs the master role is called a master, and a link layer that performs the slave role is called a slave. The master adjusts the timing of connection events, and a connection event means a synchronized point between the master and the slave.

[0210] The packets defined in the Bluetooth interface are briefly explained below. BLE devices use the packets defined below.

[0211] Packet Format

[0212] The Link Layer has only one packet format that is used for both advertising channel packets and data channel packets.

[0213] Each packet is made up of four fields: a preamble, an access address, a PDU, and a CRC.

[0214] When a packet is transmitted on the advertisement channel, the PDU becomes an advertisement channel PDU, and when a packet is transmitted on the data channel, the PDU becomes a data channel PDU.

[0215] Advertising Channel PDU

[0216] An advertisement channel PDU (Packet Data Circuit) has a 16-bit header and a payload of various sizes.

[0217] The PDU type field of the advertising channel PDU included in the header indicates the PDU type as defined in Table 3 below.

[0218] [Table 3]

[0219] Advertising PDU

[0220] The following advertising channel PDU types are called advertising PDUs and are used for specific events.

[0221] ADV_IND: Connectable non-directional advertising event

[0222] ADV_DIRECT_IND: Connectable directional advertising event

[0223] ADV_NONCONN_IND: Non-connectable non-directed advertising event

[0224] ADV_SCAN_IND: Scannable non-directional advertising event

[0225] The PDU is transmitted by the Link Layer in the Advertising State and received by the Link Layer in the Scanning State or Initiating State.

[0226] Scanning PDU

[0227] The following advertising channel PDU types are called scanning PDUs and are used in the situations described below.

[0228] SCAN_REQ: Sent by the Link Layer in the Scanning state and received by the Link Layer in the Advertising state.

[0229] SCAN_RSP: Sent by the Link Layer in the Advertising state and received by the Link Layer in the Scanning state.

[0230] Initiating PDU

[0231] The following advertising channel PDU types are called Start PDUs.

[0232] CONNECT_REQ: Sent by the Link Layer in the Initiation state and received by the Link Layer in the Advertisement state.

[0233] Data Channel PDU

[0234] The data channel PDU has a 16-bit header, a variable size payload, and can include a Message Integrity Check (MIC) field.

[0235] The procedures, states, packet formats, etc. of the BLE technology described above can be applied to perform the method proposed in this specification.

[0236] Referring again to FIG. 4A, the load 455 is a battery. The battery can store energy by using the power output from the power pickup circuit 210. However, the mobile device 450 does not necessarily include a battery. For example, the battery can be provided in a detachable external configuration. As another example, the wireless power receiving apparatus 200 can include a driving means for driving various operations of the electronic device instead of a battery.

[0237] Although the mobile device 450 is illustrated as including a wireless power receiving device 200 and the base station 400 is illustrated as including a wireless power transmitting device 100, in a broad sense, the wireless power receiving device 200 can be considered the same as the mobile device 450, and the wireless power transmitting device 100 can be considered the same as the base station 400.

[0238] When the communication / control circuit 120 and the communication / control circuit 220 include an OB communication module or a short-range communication module such as Bluetooth or Bluetooth LE in addition to an IB communication module, the wireless power transmitting device 100 including the communication / control circuit 120 and the wireless power receiving device 200 including the communication / control circuit 220 can be represented by a simplified block diagram as shown in FIG. 4C.

[0239] FIG. 4c is a block diagram illustrating a wireless power transmission system using BLE communication according to an example.

[0240] 4c, the wireless power transmission device 100 includes a power conversion circuit 110 and a communication / control circuit 120. The communication / control circuit 120 includes an in-band communication module 121 and a BLE communication module 122.

[0241] Meanwhile, the wireless power receiving device 200 includes a power pickup circuit 210 and a communication / control circuit 220. The communication / control circuit 220 includes an in-band communication module 221 and a BLE communication module 222.

[0242] In one aspect, the BLE communication modules 122 and 222 implement the architecture and operation according to Fig. 4b. For example, the BLE communication modules 122 and 222 may be used to establish a connection between the wireless power transmitting apparatus 100 and the wireless power receiving apparatus 200 and exchange control information and packets required for wireless power transmission.

[0243] In another aspect, communication / control circuit 120 can be configured to operate a profile for wireless charging, where the profile for wireless charging is GATT using BLE transmission.

[0244] FIG. 4d is a block diagram illustrating another example of a wireless power transmission system using BLE communication.

[0245] Referring to FIG. 4d, the communication / control circuits 120 and 220 may each include only an in-band communication module 121 and 221, and the BLE communication module 122 and 222 may be provided separately from the communication / control circuits 120 and 220.

[0246] Hereinafter, a coil or a coil section including a coil and at least one element adjacent to the coil may also be referred to as a coil assembly, a coil cell, or a cell.

[0247] FIG. 5 is a state transition diagram for explaining a wireless power transmission procedure.

[0248] Referring to FIG. 5, power transmission from a wireless power transmission device according to one embodiment of the present specification to a receiver can be broadly divided into a selection phase 510, a ping phase 520, an identification and configuration phase 530, a negotiation phase 540, a calibration phase 550, a power transfer phase 560, and a renegotiation phase 570.

[0249] The selection step 510 is a step (e.g., including steps S502, S504, S508, S510, and S512) to which a transition is made when a specific error or event is detected while starting or maintaining power transmission. The specific error and event will be clarified in the following description. Furthermore, in the selection step 510, the wireless power transmission apparatus can monitor whether an object is present on the interface surface. If the wireless power transmission apparatus detects that an object has been placed on the interface surface, the wireless power transmission apparatus can transition to the PING step 520. In the selection step 510, the wireless power transmission apparatus can transmit an analog PING signal, which is a power signal (or pulse) corresponding to a fairly short duration, and detect whether an object is present in the active area of ​​the interface surface based on a change in current in the transmission coil or primary coil.

[0250] If an object is detected in the selection step 510, the wireless power transmitter may measure a quality factor of a wireless power resonant circuit (e.g., a power transmitting coil and / or a resonant capacitor). In one embodiment of the present specification, if an object is detected in the selection step 510, the quality factor may be measured to determine whether the wireless power receiver is placed in the charging area with a foreign object. The inductance and / or the series resistance component of the coil included in the wireless power transmitter may decrease due to environmental changes, thereby decreasing the quality factor value. To determine whether a foreign object is present using the measured quality factor value, the wireless power transmitter may receive a reference quality factor value measured in advance when no foreign object is present in the charging area from the wireless power receiver. The reference quality factor value received in the negotiation step 540 may be compared with the measured quality factor value to determine whether a foreign object is present. However, in the case of a wireless power receiving device with a low reference quality factor value (for example, a specific wireless power receiving device may have a low reference quality factor value depending on the type, use, and characteristics of the wireless power receiving device), there may not be a large difference between the quality factor value measured when a foreign object is present and the reference quality factor value, making it difficult to determine whether a foreign object is present. Therefore, other determination factors must be further considered or other methods must be used to determine whether a foreign object is present.

[0251] In another embodiment of the present disclosure, when an object is detected in the selection step 510, a quality factor value within a specific frequency range (e.g., an operating frequency range) can be measured to determine whether a foreign object has been placed in the charging area. The inductance and / or series resistance component of the coil of the wireless power transmission device can be reduced due to environmental changes, thereby changing (shifting) the resonant frequency of the coil of the wireless power transmission device. That is, the quality factor peak frequency, which is the frequency at which the maximum quality factor value is measured within the operating frequency band, can shift.

[0252] In step 520, when an object is detected, the wireless power transmission apparatus wakes up the receiver and transmits a digital ping to identify whether the detected object is a wireless power receiver. If the wireless power transmission apparatus cannot receive a response signal, such as a signal strength packet, to the digital ping from the receiver in step 520, it can transition back to selection step 510. Also, in step 520, the wireless power transmission apparatus can transition back to selection step 510 if it receives a signal, such as a charging completion packet, indicating that power transmission has been completed from the receiver.

[0253] Upon completion of the PING step 520, the wireless power transmitter can transition to an Identification and Configuration step 530 to identify the receiver and collect receiver configuration and status information.

[0254] In the identification and configuration step 530, the wireless power transmission device can transition to the selection step 510 if an unexpected packet is received (unexpected packet), or a desired packet is not received within a predefined time (time out), or there is a packet transmission error (transmission error), or no power transfer contract is set (no power transfer contract).

[0255] The wireless power transmitting apparatus may determine whether it is necessary to enter the negotiation stage 540 based on a negotiation field value of the configuration packet received in the identification and configuration stage 530. If the determination result indicates that negotiation is necessary, the wireless power transmitting apparatus may enter the negotiation stage 540 and perform a predetermined FO detection procedure. On the other hand, if the determination result indicates that negotiation is not necessary, the wireless power transmitting apparatus may directly enter the power transmission stage 560.

[0256] In the negotiation step 540, the wireless power transmission apparatus may receive a Foreign Object Detection (FOD) status packet including a reference quality factor value. Alternatively, the wireless power transmission apparatus may receive an FOD status packet including a reference peak frequency value. Alternatively, the wireless power transmission apparatus may receive a status packet including a reference quality factor value and a reference peak frequency value. In this case, the wireless power transmission apparatus may determine a quality factor threshold for FOD detection based on the reference quality factor value. Alternatively, the wireless power transmission apparatus may determine a peak frequency threshold for FOD detection based on the reference peak frequency value.

[0257] The wireless power transmission device may detect whether an FO exists in the charging area by using the determined quality factor threshold for FO detection and a currently measured quality factor value (the quality factor value measured before the PING step), and may control power transmission according to the FO detection result. For example, if an FO is detected, power transmission may be interrupted, but is not limited thereto.

[0258] The wireless power transmission device may detect whether an FO exists in the charging area by using the determined peak frequency threshold for FO detection and a currently measured peak frequency value (a peak frequency value measured before the PING step), and may control power transmission according to the FO detection result. For example, if an FO is detected, power transmission may be interrupted, but is not limited thereto.

[0259] If FO is detected, the wireless power transmitter may return to the selection step 510. On the other hand, if FO is not detected, the wireless power transmitter may proceed to the power transmission step 560 via the correction step 550. In particular, if FO is not detected, the wireless power transmitter may determine the strength of the power received at the receiving end in the correction step 550 and measure the power loss at the receiving end and the transmitting end to determine the strength of the power transmitted at the transmitting end. That is, the wireless power transmitter may predict the power loss based on the difference between the transmission power of the transmitting end and the reception power of the receiving end in the correction step 550. The wireless power transmitter according to an embodiment may also correct the threshold for FO detection to reflect the predicted power loss.

[0260] In the power transmission step 560, the wireless power transmission device can transition to the selection step 510 if an unexpected packet is received (unexpected packet), or a desired packet is not received within a predefined time (time out), or a violation of the pre-set power transmission contract occurs (power transfer contract violation), or charging is completed.

[0261] In addition, in the power transmission step 560, if it is necessary to reconfigure the power transmission contract due to a change in the state of the wireless power transmission device, the wireless power transmission device may transition to a renegotiation step 570. At this time, if the renegotiation is successfully completed, the wireless power transmission device may return to the power transmission step 560.

[0262] In this embodiment, the correction stage 550 and the power transmission stage 560 are separated into separate stages, but the correction stage 550 may be integrated into the power transmission stage 560. In this case, the operations in the correction stage 550 may be performed in the power transmission stage 560.

[0263] The power transmission contract may be set based on status and characteristic information of the wireless power transmitter and the receiver. For example, the status information of the wireless power transmitter may include information on a maximum transmittable power amount, information on a maximum number of receivers that can be accommodated, etc., and the status information of the receiver may include information on required power, etc.

[0264] FIG. 6 illustrates a power control method according to one embodiment.

[0265] 6, in the power transmission step 560, the wireless power transmitting apparatus 100 and the wireless power receiving apparatus 200 can control the amount of power transmitted by communicating in parallel with power transmission and reception. The wireless power transmitting apparatus and the wireless power receiving apparatus operate at a specific control point. The control point indicates the combination of voltage and current provided at the output of the wireless power receiving apparatus when power transmission is performed.

[0266] More specifically, the wireless power receiving device selects a desired control point (e.g., a desired output current / voltage, a temperature at a specific location of the mobile device, etc.), and then determines a currently operating actual control point. The wireless power receiving device can calculate a control error value using the desired control point and the actual control point, and transmit the control error value to the wireless power transmitting device as a control error packet.

[0267] The wireless power transmitter can then control power transfer by setting / controlling a new operating point (amplitude, frequency, and duty cycle) using the received control error packet. Thus, the control error packet is transmitted / received at regular time intervals during the power transfer phase. For example, the wireless power receiver can transmit a control error value by setting a negative value when trying to reduce the current of the wireless power transmitter and a positive value when trying to increase the current. In this way, in the induction mode, the wireless power receiver can control power transfer by transmitting a control error packet to the wireless power transmitter.

[0268] The resonant mode described below can operate in a different manner from the inductive mode. In the resonant mode, one wireless power transmitter must be able to simultaneously serve multiple wireless power receivers. However, when controlling power transmission as in the inductive mode, the transmitted power is controlled through communication with one wireless power receiver, making it difficult to control power transmission to additional wireless power receivers. Therefore, in the resonant mode described herein, the wireless power transmitters commonly transmit a basic power, and the wireless power receivers control the amount of power they receive by controlling their own resonant frequencies. However, even in this resonant mode operation, the method described in FIG. 6 is not completely excluded, and additional transmission power control can also be performed using the method described in FIG. 6.

[0269] 7 is a block diagram of a wireless power transmission device according to another embodiment. This may belong to a wireless power transmission system of a magnetic resonance type or a shared mode. The shared mode may refer to a mode in which one-to-many communication and charging are performed between a wireless power transmission device and a wireless power receiving device. The shared mode may be implemented in a magnetic induction type or a resonance type.

[0270] 7, the wireless power transmission device 700 may include at least one of a cover 720 that covers a coil assembly, a power adapter 730 that supplies power to a power transmitter 740, the power transmitter 740 that transmits wireless power, or a user interface 750 that provides power transfer progress and other related information. In particular, the user interface 750 may be included as an option or may be included as another user interface 750 of the wireless power transmission device 700.

[0271] The power transmitter 740 may include at least one of a coil assembly 760 , an impedance matching circuit 770 , an inverter 780 , a communication circuit 790 , or a control circuit 710 .

[0272] The coil assembly 760 includes at least one primary coil that generates a magnetic field, also referred to as a coil cell.

[0273] The impedance matching circuit 770 can provide impedance matching between the inverter and the primary coil(s). The impedance matching circuit 770 can generate a resonance at a suitable frequency to boost the primary coil current. In a multi-coil power transmitter 740, the impedance matching circuit can additionally include a multiplexer that routes signals to a subset of the primary coils at the inverter. The impedance matching circuit is also referred to as a tank circuit.

[0274] The impedance matching circuit 770 may include a capacitor, an inductor, and a switching element for switching their connections. Impedance matching may be performed by detecting a reflected wave of wireless power transmitted through the coil assembly 760 and switching the switching element based on the detected reflected wave to adjust the connection state of the capacitor or inductor, adjust the capacitance of the capacitor, or adjust the inductance of the inductor. In some cases, the impedance matching circuit 770 may be omitted, and this specification also includes an embodiment of the wireless power transmission apparatus 700 in which the impedance matching circuit 770 is omitted.

[0275] Inverter 780 can convert a DC input to an AC signal. Inverter 780 can be driven in a half-bridge or full-bridge configuration to generate a pulse wave with adjustable frequency and duty cycle. The inverter can also include multiple stages to adjust the input voltage level.

[0276] The communication circuitry 790 can perform communication with the power receiver. The power receiver performs load modulation to communicate requests and information to the power transmitter. Thus, the power transmitter 740 can monitor the amplitude and / or phase of the current and / or voltage in the primary coil to demodulate the data transmitted by the power receiver using the communication circuitry 790.

[0277] The power transmitter 740 can also control the output power so as to transmit data via the communication circuit 790 using a frequency shift keying (FSK) method or the like.

[0278] The control circuit 710 can control communication and power transfer of the power transmitter 740. The control circuit 710 can control power transmission by adjusting the operating point described above. The operating point can be determined by, for example, at least one of the operating frequency, the duty cycle, and the input voltage.

[0279] The communication circuitry 790 and the control circuitry 710 may be provided in separate circuits / components / chipsets or may be provided in a single circuit / component / chipset.

[0280] 8 shows a wireless power receiving apparatus according to another embodiment, which can belong to a magnetic resonance type or a shared mode wireless power transmitting system.

[0281] 8, the wireless power receiving device 800 may include at least one of a user interface 820 that provides power transfer progress and other related information, a power receiver 830 that receives wireless power, a load circuit 840, or a base 850 that supports and covers the coil assembly. In particular, the user interface 820 may be included as an option or may be included as another user interface 820 of the power receiving device.

[0282] The power receiver 830 may include at least one of a power converter 860 , an impedance matching circuit 870 , a coil assembly 880 , a communication circuit 890 , or a control circuit 810 .

[0283] The power converter 860 can convert the AC power received from the secondary coil into a voltage and current suitable for the load circuit. As an example, the power converter 860 can include a rectifier. The rectifier can rectify the received wireless power to convert AC to DC. The rectifier can convert AC to DC using a diode or a transistor and smooth the DC using a capacitor and a resistor. The rectifier can be a full-wave rectifier, a half-wave rectifier, a voltage multiplier, or the like, implemented as a bridge circuit. Additionally, the power converter can adapt the reflected impedance of the power receiver.

[0284] The impedance matching circuit 870 may provide impedance matching between the combination of the power converter 860 and the load circuit 840 and the secondary coil. As an example, the impedance matching circuit may generate a resonance around 100 kHz, which can enhance power transfer. The impedance matching circuit 870 may be configured with a capacitor, an inductor, or a switching element that switches a combination of these. Impedance matching may be performed by controlling the switching elements of the circuit constituting the impedance matching circuit 870 based on the voltage value, current value, power value, frequency value, etc. of the received wireless power. In some cases, the impedance matching circuit 870 may be omitted, and this specification also includes an embodiment of the wireless power receiving apparatus 200 in which the impedance matching circuit 870 is omitted.

[0285] The coil assembly 880 includes at least one secondary coil and may optionally further include elements for shielding metallic portions of the receiver from magnetic fields.

[0286] The communications circuitry 890 may perform load modulation to communicate requests and other information to the power transmitter.

[0287] To that end, the power receiver 830 may also switch resistors or capacitors to change the reflected impedance.

[0288] The control circuit 810 can control the received power. To do so, the control circuit 810 can determine / calculate the difference between the actual operating point and the desired operating point of the power receiver 830. The control circuit 810 can then adjust / reduce the difference between the actual operating point and the desired operating point by adjusting the reflected impedance of the power transmitter and / or executing an operating point adjustment request for the power transmitter. When this difference is minimized, optimal power reception can be achieved.

[0289] The communication circuitry 890 and the control circuitry 810 may be provided in separate components / chipsets or may be provided in a single component / chipset.

[0290] 9 shows a communication frame structure according to one embodiment, which is a communication frame structure in shared mode.

[0291] 9, different types of frames can be used together in the shared mode. For example, in the shared mode, a slotted frame having multiple slots as shown in (A) and a free format frame without a specific format as shown in (B) can be used. More specifically, the slotted frame is a frame for transmitting a short data packet from the wireless power receiving apparatus 200 to the wireless power transmitting apparatus 100, and the free format frame is a frame that does not have multiple slots and can transmit a long data packet.

[0292] Meanwhile, the slot frame and the free form frame may be renamed to various names by those skilled in the art, for example, the slot frame may be renamed to a channel frame, and the free form frame may be renamed to a message frame.

[0293] More specifically, the slot frame may include a sync pattern indicating the start of a slot, a measurement slot, nine slots, and additional sync patterns each having the same time interval before the nine slots.

[0294] Here, the additional sync pattern is a sync pattern different from the sync pattern indicating the start of a frame described above. More specifically, the additional sync pattern may indicate information related to adjacent slots (i.e., two consecutive slots located on both sides of the sync pattern) without indicating the start of a frame.

[0295] A sync pattern may be positioned between each two consecutive slots among the nine slots, and in this case, the sync pattern may provide information related to the two consecutive slots.

[0296] The nine slots and the sync patterns provided before each of the nine slots may each have the same time interval. For example, the nine slots may have a time interval of 50 ms. The nine sync patterns may also have a time length of 50 ms.

[0297] On the other hand, a free format frame such as (B) does not have a specific form other than a sync pattern indicating the start of a frame and a measurement slot. That is, the free format frame is intended to perform a different role from the slot frame, for example, to communicate a long data packet (e.g., an additional owner information packet) between the wireless power transmitting apparatus and the wireless power receiving apparatus, or to select one of multiple coils in a wireless power transmitting apparatus configured with multiple coils.

[0298] Hereinafter, the sync pattern included in each frame will be described in more detail with reference to the drawings.

[0299] FIG. 10 shows the structure of a sync pattern according to one embodiment.

[0300] Referring to Figure 10, the sync pattern may consist of a preamble, a start bit, a response field, a type field, an information field, and a parity bit. In Figure 10, the start bit is indicated by ZERO.

[0301] More specifically, the preamble consists of consecutive bits and can be set to all 0. That is, the preamble is a bit for adjusting the time length of the sync pattern.

[0302] The number of bits constituting the preamble can depend on the operating frequency so that the length of the sync pattern is closest to, but not exceeding, 50 ms. For example, if the operating frequency is 100 kHz, the sync pattern can be composed of two preamble bits, and if the operating frequency is 105 kHz, the sync pattern can be composed of three preamble bits.

[0303] The start bit is the bit following the preamble and may represent a zero. The zero indicates the type of sync pattern. Here, the type of sync pattern may include a frame sync containing information related to a frame and a slot sync containing information about a slot. That is, the sync pattern may be a frame sync located between consecutive frames and indicating the start of a frame, or a slot sync located between consecutive slots among a plurality of slots constituting a frame and containing information related to the consecutive slots.

[0304] For example, if the zero is 0, it means that the corresponding slot is a slot sync located between slots, and if it is 1, it means that the corresponding sync pattern is a frame sync located between frames.

[0305] The parity bit is the last bit of the sync pattern and can indicate the number of bits constituting the data field (i.e., response field, type field, information field) of the sync pattern. For example, the parity bit can be 1 if the number of bits constituting the data field of the sync pattern is even, and can be 0 otherwise (i.e., odd).

[0306] The response field may contain response information of the wireless power transmitting device in response to communication with the wireless power receiving device in a slot before the sync pattern. For example, the response field may contain '00' if no communication with the wireless power receiving device is detected. Also, the response field may contain '01' if a communication error is detected in communication with the wireless power receiving device. A communication error occurs when two or more wireless power receiving devices attempt to access one slot, causing a collision between the two or more wireless power receiving devices.

[0307] The response field may include information indicating whether the data packet has been correctly received from the wireless power receiving apparatus. More specifically, the response field may be set to “10” (10—not acknowledge, NAK) if the wireless power transmitting apparatus rejects the data packet, and may be set to “11” (11—acknowledge, ACK) if the wireless power transmitting apparatus confirms the data packet.

[0308] The type field may indicate the type of sync pattern. More specifically, if the sync pattern is the first sync pattern of a frame (i.e., the first sync pattern of a frame and located before the measurement slot), the type field may have a value of '1', indicating that the sync pattern is a frame sync.

[0309] Also, the type field may have '0' indicating that it is a slot sync if the sync pattern is not the first sync pattern of the frame in a slot frame.

[0310] In addition, the meaning of the value of the information field can be determined depending on the type of sync pattern indicated by the type field. For example, if the type field is 1 (i.e., if it indicates a frame sync), the meaning of the information field can indicate the type of frame. That is, the information field can indicate whether the current frame is a slotted frame or a free-format frame. For example, if the information field is '00', it indicates a slotted frame, and if the information field is '01' it indicates a free-format frame.

[0311] On the other hand, if the type field is 0 (i.e., slot sync), the information field may indicate the status of the next slot located after the sync pattern. More specifically, the information field may have '00' if the next slot is allocated to a specific wireless power receiving device, '01' if the slot is locked for temporary use by a specific wireless power receiving device, or '10' if the slot is freely available to any wireless power receiving device.

[0312] FIG. 11 illustrates an operation state of a wireless power transmitter and a wireless power receiver in a shared mode according to an embodiment.

[0313] Referring to FIG. 11, a wireless power receiving device operating in a sharing mode can operate in any one of a selection phase 1100, an introduction phase 1110, a configuration phase 1120, a negotiation phase 1130, and a power transfer phase 1140.

[0314] First, a wireless power transmitter according to an embodiment may transmit a wireless power signal to detect a wireless power receiver. That is, a process of detecting a wireless power receiver using a wireless power signal is called analog ping.

[0315] Meanwhile, a wireless power receiving device that receives a wireless power signal can enter a selection state 1100. The wireless power receiving device that enters the selection state 1100 can detect the presence of an FSK signal in the wireless power signal, as described above.

[0316] That is, the wireless power receiving apparatus can perform communication in either an exclusive mode or a shared mode depending on whether an FSK signal is present.

[0317] More specifically, the wireless power receiving device operates in a shared mode if the wireless power signal includes an FSK signal, and operates in an exclusive mode if the wireless power signal does not include an FSK signal.

[0318] When the wireless power receiving apparatus operates in a shared mode, the wireless power receiving apparatus may enter an introduction state 1110. In the introduction state 1110, the wireless power receiving apparatus may transmit a control information packet (CI) to the wireless power transmitting apparatus in order to transmit a control information packet in the configuration state, negotiation state, and power transmission state. The control information packet may have a header and information related to control. For example, the control information packet has a header of 0X53.

[0319] In the introduction state 1110, the wireless power receiving device attempts to request a free slot to transmit a control information (CI) packet through the following configuration, negotiation, and power transmission stages. At this time, the wireless power receiving device selects a free slot and transmits the first CI packet. If the wireless power transmitting device responds to the corresponding CI packet with an ACK, the wireless power transmitting device enters the configuration stage. If the wireless power transmitting device responds with a NAK, it means that another wireless power receiving device is proceeding through the configuration and negotiation stages. In this case, the wireless power receiving device attempts to request a free slot again.

[0320] If the wireless power receiving device receives an ACK in response to a CI packet, the wireless power receiving device determines the location of a private slot in the U frame by counting the remaining slot syncs up to the first frame sync. In all subsequent slot-based frames, the wireless power receiving device transmits a CI packet through the corresponding slot.

[0321] If the wireless power transmitter permits the wireless power receiver to proceed to the configuration stage, the wireless power transmitter provides a series of locked slots for the exclusive use of the wireless power receiver, which ensures that the wireless power receiver proceeds to the configuration stage without collision.

[0322] The wireless power receiving device transmits a sequence of data packets, such as two identification data packets (IDHI and IDLO), using the lock slot. Upon completing this phase, the wireless power receiving device enters the negotiation phase. In the negotiation phase, the wireless power transmitting device continues to provide the wireless power receiving device with a lock slot for exclusive use. This ensures that the wireless power receiving device proceeds through the negotiation phase without collisions.

[0323] The wireless power receiving device uses the corresponding lock slot to transmit one or more negotiation data packets, which may be intermixed with private data packets. The sequence is eventually terminated with a specific request (SRQ) packet. Upon completing the sequence, the wireless power receiving device enters the power transmission phase, and the wireless power transmitting device ceases providing the lock slot.

[0324] In the power transmission state, the wireless power receiving device transmits a CI packet using the assigned slot to receive power. The wireless power receiving device may include a regulator circuit. The regulator circuit may be included in the communication / control circuit. The wireless power receiving device can self-regulate its reflected impedance via the regulator circuit. That is, the wireless power receiving device can adjust the reflected impedance to transmit the amount of power required by the external load. This can prevent excessive power reception and overheating.

[0325] In shared mode, the wireless power transmitter may not adjust power in response to received CI packets (depending on the operating mode), in which case control is needed to prevent overvoltage conditions.

[0326] The following describes authentication between a wireless power transmitting device and a wireless power receiving device.

[0327] A wireless power transmission system using in-band communication can use USB-C authentication, which includes authentication of a wireless power transmitting device by a wireless power receiving device, and authentication of a wireless power receiving device by a wireless power transmitting device.

[0328] FIG. 12 is a block diagram illustrating a wireless charging certificate format according to an embodiment.

[0329] Referring to FIG. 12, the wireless charging certificate format includes a certificate structure version, a reserved bit, a certificate type, a signature offset, a serial number, an issuer ID, a subject ID, a public key, and a signature.

[0330] The certificate type may be, for example, 3 bits, and may indicate that the corresponding certificate is one of a root certificate, intermediate certificate, or final certificate, or may indicate that the certificate is a certificate for a wireless power transmitting device or a certificate for a wireless power receiving device, or may indicate all of these.

[0331] For example, the certificate type is 3 bits and can indicate information on the Root Certificate, Manufacturer / Secondary Certificate, Product Unit Certificate (for the Power Transmitter), etc. More specifically, if the certificate type is '001'b, it indicates the Root Certificate, if it is '010'b, it indicates the Intermediate Certificate (Manufacturer / Secondary Certificate), and if it is '111'b, it indicates the Product Unit Certificate for the Power Transmitter, which is the final certificate.

[0332] The wireless power transmitter can inform the wireless power receiver whether it supports the authentication function using a capability packet (in the case of authentication of the wireless power transmitter by the wireless power receiver (authentication of PTx by PRx)). Meanwhile, the wireless power receiver can inform the wireless power transmitter whether it supports the authentication function using a configuration packet (in the case of authentication of the wireless power receiver by the wireless power transmitter (authentication of PRx by PTx)). The structure of the indication information (capability packet and configuration packet) for whether the authentication function is supported will be disclosed in more detail below.

[0333] FIG. 13 shows a performance packet structure of a wireless power transmission apparatus according to an embodiment.

[0334] 13, a performance packet having a corresponding header value of 0X31 has three bytes, where the first byte (B0) includes a power class and a guaranteed power value, the second byte (B1) includes reserved and a potential power value, and the third byte (B2) includes an authentication initiator (AI), an authentication responder (AR), reserved, WPID, and Not Responsible. Specifically, the authentication initiator is 1 bit, and if its value is '1b', it indicates that the corresponding wireless power transmission apparatus can operate as an authentication initiator. Also, the authentication responder is 1 bit, and if its value is '1b', it indicates that the corresponding wireless power transmission apparatus can operate as an authentication responder.

[0335] FIG. 14 shows a configuration packet structure of a wireless power receiving apparatus according to an embodiment.

[0336] 14, a configuration packet having a corresponding header value of 0X51 has five bytes, where the first byte (B0) includes a power class and a maximum power value, the second byte (B1) includes AI, AR, and Reserved, the third byte (B2) includes Prop, Reserved, ZERO, and Count, the fourth byte (B3) includes a window size and a window offset, and the fifth byte (B4) includes Neg, Polarity, Depth, Authentication, and Reserved. Specifically, the authentication initiator is 1 bit, and if its value is '1b', it indicates that the corresponding wireless power receiving apparatus can operate as an authentication initiator. Also, the authentication responder is 1 bit, and if its value is '1b', it indicates that the corresponding wireless power receiving apparatus can operate as an authentication responder.

[0337] A message used in the authentication procedure is called an authentication message. An authentication message is used to carry information related to authentication. There are two types of authentication messages. One is an authentication request and the other is an authentication response. An authentication request is sent by an authentication initiator, and an authentication response is sent by an authentication responder. The wireless power transmitting device and the receiving device can be either an authentication initiator or an authentication responder. For example, if the wireless power transmitting device is the authentication initiator, the wireless power receiving device becomes the authentication responder, and if the wireless power receiving device is the authentication initiator, the wireless power transmitting device becomes the authentication responder.

[0338] The authentication request message includes GET_DIGESTS (for example, 4 bytes), GET_CERTIFICATE (for example, 8 bytes), and CHALLENGE (for example, 36 bytes).

[0339] The authentication response message includes DIGESTS (for example, 4 + 32 bytes), CERTIFICATE (for example, 4 + certificate chain (3 x 512 bytes) = 1540 bytes), CHALLENGE_AUTH (for example, 168 bytes), and ERROR (for example, 4 bytes).

[0340] An authentication message is also called an authentication packet, authentication data, or authentication control information. Messages such as GET_DIGEST and DIGESTS are also called GET_DIGEST packets and DIGEST packets.

[0341] FIG. 15 illustrates an application-level data stream between a wireless power transmitting device and a receiving device according to an example.

[0342] Referring to FIG. 15, the data stream may include auxiliary data control (ADC) data packets and / or auxiliary data transport (ADT) data packets.

[0343] The ADC data packet is used when opening a data stream. The ADC data packet can indicate the type of message and the number of data bytes contained in the stream. In contrast, the ADT data packet is a sequence of data that contains the actual message. The ADC / end data packet is used to signal the end of the stream. For example, the maximum number of data bytes in a data transmission stream can be limited to 2047.

[0344] ACK or NAC (NACK) is used to indicate whether the ADC data packet and ADT data packet have been received normally. Control information required for wireless charging, such as a control error packet (CE) or DSR, can be transmitted between the transmission timings of the ADC data packet and ADT data packet.

[0345] Using this data stream structure, authentication-related information or other application-level information can be transmitted and received between the wireless power transmitting device and the receiving device.

[0346] A method for detecting foreign objects and correcting power will now be described.

[0347] When a wireless power transmitter transmits wireless power to a wireless power receiver using a magnetic field, if a foreign object is present in the vicinity, a portion of the magnetic field is absorbed by the foreign object. That is, a portion of the wireless power transmitted by the wireless power transmitter is supplied to the foreign object, and the remainder is supplied to the wireless power receiver. From the perspective of power transmission efficiency, the amount of power or energy absorbed by the foreign object is equivalent to a loss of transmission power. As a causal relationship can be established between the presence of a foreign object and power loss, the wireless power transmitter can detect a foreign object based on the amount of power loss. This foreign object detection method can be called a power loss-based foreign object detection method.

[0348] The power lost due to a foreign object can be defined as the power transmitted by the wireless power transmitter (Ptransmitted) minus the power actually received by the wireless power receiver (Preceived). Since the wireless power transmitter knows its transmitted power (Ptransmitted), the lost power can be calculated when the wireless power receiver knows only the power actually received (Preceived). To this end, the wireless power receiver can notify the wireless power transmitter of the received power (Preceived) by transmitting a received power packet (RPP) to the wireless power transmitter.

[0349] Meanwhile, a wireless power transmitter and a wireless power receiver are configured with numerous internal circuit components and are independent of each other. However, because wireless power is transmitted between them through magnetic coupling, the wireless power transmitter and the wireless power receiver constitute a single wireless power transmission system. The amount of power transmitted by the wireless power transmitter (transmission power) and the amount of power received by the wireless power receiver (received power) are uniquely determined by the power transmission characteristics. For example, the power transmission characteristics can be viewed as a ratio or function of the transmission power and the received power. Therefore, if the wireless power transmitter knows the power transmission characteristics in advance, it can predict how much of its transmitted power will be received by the wireless power receiver. If the actual received power reported by the wireless power receiver is lower than the received power predicted based on the power transmission characteristics, it can be determined that a power loss has occurred during the power transmission process. A foreign object detection method based on power loss can determine the presence of a foreign object in such a case. Since the power loss used to determine a foreign object is also determined based on the power transmission characteristics, accurate understanding of the power transmission characteristics is necessary to improve the reliability of foreign object detection.

[0350] The power transmission characteristics depend on the environment or the inherent characteristics of the device transmitting the wireless power. In order to determine the power transmission characteristics in any given wireless charging environment, the wireless power transmitting device and the receiving device may generally use power calibration at the start of wireless power transmission. Once the power transmission characteristics are determined or set by the power calibration, foreign object detection is performed accordingly.

[0351] The power transmission characteristics also depend on changes in load or the degree of magnetic coupling. For example, if the wireless power receiving device uses multiple load steps or load variations (or load increases), or if the degree of magnetic coupling changes due to a change in the position between the wireless power transmitting device and the receiving device, at least a portion of the power transmission characteristics may change. If at least a portion of the power transmission characteristics change, at least a portion of the power correction set according to the previous power transmission characteristics becomes invalid. Furthermore, the power loss and foreign object detection based on at least a portion of the set power correction also becomes invalid. Therefore, additional power corrections are needed to match the changed power transmission characteristics.

[0352] Power correction due to load change (1)

[0353] FIG. 16 is a flow diagram illustrating a method for performing power correction and foreign object detection according to one embodiment.

[0354] 16, the wireless power receiving apparatus receives and measures transmission power (hereinafter referred to as first light-load transmission power; Ptr_light) from the wireless power transmitting apparatus under a light-load condition, and then transmits a first received power packet (RPP) indicating the received power value under the light-load condition to the wireless power transmitting apparatus (S1400). The first received power packet may have, for example, a format shown in FIG. 17.

[0355] FIG. 17 illustrates a format of a received power packet according to an example.

[0356] 17, the received power packet may be, for example, 24 bits in total, and may include a field (e.g., 8 bits) indicating an estimated received power value and a mode field (e.g., 3 bits). The mode field indicates how to interpret the received power value. Table 4 shows an example of the mode field.

[0357]

Table 4

[0358] Referring to Table 4, when the mode field is '000', it indicates that the received power value is a general power value (which can be represented by RP / 0), and when the mode field is '001' or '010', it indicates that the received power packet is related to power calibration (which can be represented by RP / 1 or RP / 2, respectively). That is, the wireless power receiving apparatus can instruct the wireless power transmitting apparatus to perform power calibration by transmitting a received power packet with the mode field = '001' or '010'. Specifically, when the mode field is '001' (i.e., RP / 1), the received power packet indicates the first information for constructing a power calibration curve and can generally indicate the power value received by the wireless power receiving apparatus when the wireless power receiving apparatus is in a light-load condition (hereinafter, referred to as the light-load calibration value, Prec_light). Also, if the mode field is '010' (i.e., RP / 2), the received power packet indicates additional information for constructing a power calibration curve and may generally indicate a power value received by the wireless power receiving apparatus when the wireless power receiving apparatus is in a connected-load condition (hereinafter, referred to as a connected-load calibration value, Prec_connected). The light-load condition may indicate a condition in which a load (e.g., a battery) is not electrically connected to the wireless power receiving apparatus, and the connected-load condition may indicate a condition in which a load is connected to the wireless power receiving apparatus. Meanwhile, the wireless power transmitting apparatus can know that power calibration is in progress by receiving a received power packet with the mode field = '001' or '010' from the wireless power receiving apparatus. Referring again to FIG. 16, the first received power packet indicates a received power value measured under a light-load condition (i.e., a light-load calibration value, Prec_light), so the mode field of the first received power packet is '001' (i.e., RP / 1). Therefore, step S1400 may further include the wireless power receiving device setting the mode field to '001'.If the mode field is found to be '001', the wireless power transmitter can identify that the received power value indicated by the first received power packet is the first information for constructing a power correction curve, and the first information for constructing the power correction curve is the light load correction value (Prec_light). The wireless power transmitter can store the light load correction value (Prec_light) in a memory to perform power correction. Although not shown in the drawings, the wireless power transmitter can transmit an ACK or NAK to the wireless power receiver in response to the first received power packet. In addition, the first received power packet can be transmitted multiple times consecutively until an ACK response is received from the wireless power transmitter. In this case, the consecutively transmitted first received power packets (i.e., RP / 1) are treated as one received power packet (i.e., a single RP / 1).

[0359] In one aspect, when receiving RP / 1, the wireless power transmitting device transmits a NAK (while monitoring the CE value) until the wireless power receiving device stably reaches the corresponding power level, and after the power level stabilizes, transmits an ACK and takes the RP1 value at that time.

[0360] The wireless power receiving device receives and measures the first connected load transmission power (Ptr_connected(1)) from the wireless power transmitting device under the first connected load condition (connected-load condition), and then transmits a second received power packet (i.e., RP / 2) indicating the first connected load correction value (Prec_connected(1)) to the wireless power transmitting device (S1405).

[0361] Step S1405 may further include the wireless power receiving apparatus setting the mode field to '010'. If it is determined that the mode field is '010', the wireless power transmitting apparatus identifies that the received power value indicated by the second received power packet is the first connected load correction value (Prec_connected(1)). The wireless power transmitting apparatus may store the first connected load correction value (Prec_connected(1)) in a memory to perform power correction.

[0362] Although not shown in the drawings, the wireless power transmitter can transmit an ACK or NAK to the wireless power receiver in response to the second received power packet (RP / 2). The second received power packet (RP / 2) can also be transmitted multiple times consecutively. In this case, the continuously transmitted second received power packets (RP / 2) are treated as one received power packet (i.e., a single RP / 2). When receiving RP / 2, the wireless power transmitter transmits a NAK (while monitoring the CE value) until the wireless power receiver stably reaches the corresponding power level. After the power level stabilizes, the wireless power transmitter transmits an ACK and takes the RP2 value at that time.

[0363] The light load transmission power (Ptr_light), the light load correction value (Prec_light), the first connected load transmission power (Ptr_connected(1)), and the first connected load correction value (Prec_connected(1)) obtained through steps S1400 and S1405 are referred to as power correction data. Power transmission characteristics can be derived or set using the power correction data. The derived power transmission characteristics are also referred to as a calibration curve. Throughout this specification, the operation of calculating, deriving, or setting the power transmission characteristics, or the operation of deriving, setting, or calculating the calibration curve is generally referred to as power calibration. In this embodiment, the power calibration performed at the start of the power transmission step is referred to as initial power calibration. Therefore, the wireless power transmission device performs initial power calibration using RP1 and RP2 at the time of sending ACK.

[0364] FIG. 18 is a power transmission characteristic or correction curve according to one embodiment.

[0365] Referring to Figure 18, when the power correction data (light load transmission power (Ptr_light), light load correction value (Prec_light), first connected load transmission power (Ptr_connected(1))), and first connected load correction value (Prec_connected(1))) are expressed in the form of coordinates (x, y) consisting of pairs of transmission power and received power, one is the first coordinate (Ptr_light, Prec_light) under light load conditions, and the other is the second coordinate (Ptr_connected(1), Prec_connected(1)) under first connected load conditions.

[0366] When the first and second coordinates are expressed as a graph by linear interpolation, a power transmission characteristic or correction curve as shown in Figure 18 can be derived. The power transmission characteristic (or correction curve) has a gradient a and a y-axis offset b. Here, a is referred to as a first correction constant, and b is referred to as a second correction constant.

[0367] The process of deriving the correction constants a and b can be expressed mathematically as follows:

[0368]

number

[0369]

number

[0370] The power transmission characteristics (or calibration curve) shown in FIG. 18 is derived using two coordinates under two load conditions, and is therefore also called 2-point calibration.

[0371] On the one hand, power correction is effective within the range of power correction data (i.e., the range where the transmission power Ptr satisfies Ptr_light ≦ Ptr ≦ Ptr_connected(1)). That is, when the first connected load transmission power is used as power correction data, the corresponding power correction is effective within a range smaller than or equal to the first connected load transmission power. In contrast, it is not effective in a range larger than the first connected load transmission power (for example, the range where Ptr_connected(1) < Ptr). If the wireless power transmission device performs power correction by extrapolating a range not covered by the correction curve, false detection or undetected foreign objects may occur.

[0372] Again, referring to FIG. 16, the wireless power receiving device changes the connected load (S1410). The change in the connected load can include an increase or a decrease in the connected load. The change in the connected load can mean that the target rectified voltage (target Vrec) or the target power of the wireless power receiving device increases or decreases compared to the previous connected load. The situation where the connected load is changed can include the case where the wireless power receiving device uses multiple load steps to reach the target power. When the connected load is changed, at least a part of the previously set power transmission characteristics can be changed, or additional power transmission characteristics can be set while maintaining the previously set power transmission characteristics. For example, when the transmission power Ptr increases to a range where Ptr_connected(1) < Ptr due to an increase in the connected load, the power transmission characteristics in FIG. 18 cannot cover this situation.

[0373] Therefore, additional power correction data is required to reflect the changed state of the connected load in the power correction. To this end, the wireless power receiving apparatus receives and measures a second connected load transmission power (Ptr_connected(2)) from the wireless power transmitting apparatus under the second connected load condition, and then transmits a third received power packet indicating a second connected load correction value (Prec_connected(2)) to the wireless power transmitting apparatus (S1415). If the wireless power transmitting apparatus responds with an ACK to the second received power packet (RP / 2) in step S1410, additional RP / 2 transmission from the wireless power receiving apparatus may not be permitted. However, to improve the power loss-based foreign object detection function, the restriction on the timing of power correction may be removed, and multi-point power correction (more than two points) may be required. Therefore, transmission of the third received power packet may be permitted as in step S1415.

[0374] Step S1415 may further include the wireless power receiving device setting the mode field to '010'. If the wireless power transmitting device determines that the mode field is '010', the wireless power transmitting device identifies that the received power value indicated by the third received power packet is the second connected load correction value (Prec_connected(2)). Because the mode field is '010', the wireless power transmitting device can know that additional power correction is required.

[0375] The wireless power transmission apparatus can store the second connected load correction value (Prec_connected(2)) in a memory in order to perform power correction.

[0376] Based on the power correction data obtained through steps S1400 to S1415, power transmission characteristics can be derived or set. The derived power transmission characteristics can be represented graphically using an interpolation technique as shown in FIG.

[0377] FIG. 19 shows a power transmission characteristic or correction curve according to another embodiment.

[0378] Referring to FIG. 19, when the power correction data (light load transmission power (Ptr_light), light load correction value (Prec_light), first connected load transmission power (Ptr_connected(1))), first connected load correction value (Prec_connected(1)), second connected load transmission power (Ptr_connected(2))), and second connected load correction value (Prec_connected(2))) are expressed in the form of coordinates (x, y) consisting of pairs of transmission power and reception power, they become the first coordinate (Ptr_light, Prec_light), the second coordinate (Ptr_connected(1), Prec_connected(1)), and the third coordinate (Ptr_connected(2), Prec_connected(2)).

[0379] When the first to third coordinates are expressed as a graph by linear interpolation, a power transmission characteristic or correction curve with different slopes for each section can be derived as shown in Figure 19. For ease of explanation, the first to third coordinates are defined as (x0, y0), (x1, y1), and (x2, y2), respectively.

[0380] The power transmission characteristics (or correction curve) in the first section (x0 to x1) have a slope of a0 and are derived with a y-axis offset of b0. The power transmission characteristics (or correction curve) in the second section (x1 to x2) have a slope of a1 and are derived with a y-axis offset of b1. The process of deriving the correction constants a0, b0, a1, and b1 can be expressed mathematically as follows:

[0381]

number

[0382]

number

[0383]

number

[0384]

Number

[0385] Since the power transmission characteristics (or correction curve) according to FIG. 19 are derived using three coordinates under three load conditions, it is also called 3-point correction or multiple calibration.

[0386] Comparing FIG. 19 with FIG. 18, it can be known that the correction range of 3-point correction is increased up to Ptr_connected(2) compared to 2-point correction. Therefore, foreign object detection is also possible in the section where the transmission power is Ptr_connected(1) < Ptr ≦ Ptr_connected(2).

[0387] Thereafter, when the wireless power receiving device receives a received power packet that instructs a general value (e.g., mode field = '000'b) Preceived instead of a received power packet related to further power correction for the power Ptransmitted transmitted by the wireless power transmitting device (e.g., mode field = '001'b or '010'b) (S1420), the wireless power transmitting device ends the power correction and performs foreign object detection based on the transmission power Ptransmitted and the received power Preceived (S1425). For example, step S1425 may include the step of the wireless power transmitting device performing foreign object detection based on power loss according to FIG. 20.

[0388] Although not shown in the drawings, the wireless power transmitting device transmits an ACK or NAK to the wireless power receiving device as a response to receiving a received power packet related to power correction.

[0389] Specifically, the wireless power transmitting device can repeat the operation of transmitting NAK to the wireless power receiving device until control is performed at a desired operating point.

[0390] For example, according to the embodiment of FIG. 16, after transmitting a first received power packet to the wireless power transmitter (S1400), if a NAK is received, the wireless power receiver can change the operating point and transmit a control error packet to the wireless power transmitter. When control is performed at the desired operating point, the wireless power transmitter transmits an ACK to the wireless power receiver. From the perspective of the wireless power transmitter, the wireless power transmitter determines, based on the received control error packet, whether the first received power packet was transmitted when the wireless power receiver was in a stable state. That is, if it is determined that the wireless power receiver is not yet stabilized, the wireless power transmitter transmits a NAK to the first received power packet. When control is performed at the desired operating point by changing the operating point, the wireless power transmitter transmits an ACK to the wireless power receiver.

[0391] Upon receiving an ACK in response to the first received power packet, the wireless power receiving apparatus transmits a second received power packet to the wireless power transmitting apparatus (S1405). The wireless power receiving apparatus transmits a control error packet to the wireless power transmitting apparatus between received power packets to inform the wireless power transmitting apparatus of the degree to which the operating point of the wireless power receiving apparatus deviates from the target operating point. This operation is repeated every time the wireless power receiving apparatus receives a NAK in response to the second received power packet, and is completed only when the wireless power transmitting apparatus transmits an ACK to the wireless power receiving apparatus when control is performed at the desired operating point.

[0392] Thereafter, the wireless power receiving apparatus transmits a third received power packet to the wireless power transmitting apparatus (S1415) by changing the connected load (S1410), and can transmit a control error packet to the wireless power transmitting apparatus. This operation is repeated every time the wireless power receiving apparatus receives a NAK in response to the second received power packet. When the wireless power transmitting apparatus has performed control at the desired operating point, it transmits an ACK to the wireless power receiving apparatus, and the wireless power transmitting apparatus ends the power correction.

[0393] Thereafter, when the wireless power receiving device receives a received power packet indicating a general value (e.g., mode field = '000'b) Preceived, not a received power packet related to power correction (e.g., mode field = '001'b or '010b') (S1420), the wireless power transmitting device corrects Preceived based on the power correction, calculates the power loss, and performs foreign object detection based on the power loss (S1425).

[0394] Meanwhile, other embodiments include a wireless power transmitting apparatus and method, and a wireless power receiving apparatus and method, that perform power correction associated with an authentication procedure.

[0395] For example, a wireless power receiving apparatus that supports authentication may adaptively perform power correction depending on whether a wireless power transmitting apparatus is authenticated or the authentication progress stage.

[0396] For example, this embodiment includes a wireless power receiving device and method that perform a step of performing power correction using a connected load corresponding to a basic power profile (BPP or 5W) when entering an initial power transmission step, a step of verifying that the wireless power transmitting device supports a certified (e.g., Qi-certified) extended power profile (EPP or 5W or more), a step of entering into a power transmission contract at a desired target power value (e.g., 8W or 15W) if the verification result and authentication are successfully performed, and a step of transmitting a received power packet for power correction under the connected load condition to the wireless power transmitting device.

[0397] Thus, the wireless power transmitter is controlled to perform additional power correction. Here, the step of establishing a power transmission contract at a target power value (e.g., 8 W or 15 W) can be performed in the renegotiation step. When the wireless power transmitter receives the received power packet (RP / 1) under a light load condition or the received power packet (RP / 2) under a connected load condition, the wireless power transmitter can transmit an ACK signal to RP(1) or RP(2) to notify the wireless power receiver that the power correction operation has been successfully performed when controlled at a desired operating point by referring to the control error packet value.

[0398] FIG. 20 is a flowchart illustrating a foreign object detection method according to one embodiment.

[0399] 20, the wireless power transmission apparatus compares the transmission power Ptransmitted with power correction data x0, x1, and x2 to determine which correction interval the transmission power belongs to (S1800, S1820). If the transmission power Ptransmitted is between x0 and x1 (S1800), the wireless power transmission apparatus calculates a corrected transmission power value Pcalibrated using correction constants a0 and b0 (S1805). If the transmission power Ptransmitted is between x1 and x2 (S1820), the wireless power transmission apparatus calculates a corrected transmission power value Pcalibrated using correction constants a1 and b1 (S1825).

[0400] After calculating the corrected transmission power value Ptransmitted, the wireless power transmission apparatus calculates the power loss Ploss from the difference between the corrected transmission power value Ptransmitted and the received power Preceived (S1810), and then detects a foreign object based on the power loss Ploss (S1815).

[0401] Since the correction range is increased, a wider range of power values ​​can be corrected, and since the reliability of the correction is increased in this way, the reliability of foreign object detection based on power loss can also be increased.

[0402] Although this embodiment describes a case where three received power packets related to power correction are continuously transmitted and received, the present invention is not limited to this embodiment. That is, embodiments according to the present invention also include a case where more received power packets related to power correction (e.g., received power packets RP / 1 and RP / 2 for power correction calculation) are continuously transmitted and received depending on the number of changes in the connected load or the number of multiple load stages.

[0403] In addition, according to this embodiment, if the load of the wireless power receiving device changes during the power transmission step, an operation of performing power correction during the power transmission step is included. That is, from step S1400 to step S1425, the wireless power transmitting device and the wireless power receiving device are operating in the power transmission step, and the wireless power transmitting device can continue to transmit wireless power.

[0404] The wireless power transmission apparatus in the embodiments of Figures 16 to 20 corresponds to the wireless power transmission apparatus, wireless power transmitter, or power transmission unit disclosed in Figures 1 to 15. Therefore, the operation of the wireless power transmission apparatus in the embodiments is implemented by one or a combination of two or more of the components of the wireless power transmission apparatus in Figures 1 to 15. For example, in the embodiments, the operation of transmitting wireless power may be performed by the power conversion unit 110. Also, in the embodiments, the operation of receiving a received power packet, the operation of performing power correction, the operation of deriving or calculating power transmission characteristics, the operation of performing FOD, etc. may be performed by the communication / control unit 120.

[0405] 16 to 20 correspond to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power receiving apparatus in the present embodiment is implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in FIGS. 1 to 15. For example, in the present embodiment, the operation of receiving wireless power may be performed by the power pickup unit 210. In addition, in the present embodiment, the operation of generating and transmitting a received power packet, the operation of performing power correction, the operation of performing FOD, etc. may be performed by the communication / control unit 220.

[0406] 21 is a flow chart illustrating a method for performing power calibration and foreign object detection according to another embodiment of the present invention. This embodiment relates to power re-calibration, which performs power calibration again after a renegotiation stage.

[0407] 21, after the wireless power transmitting device and the wireless power receiving device establish an initial basic power contract (e.g., 5 W) in the negotiation stage, the wireless power transmitting device and the wireless power receiving device perform power correction at the start of the power transmission stage (S1900). At this time, the power correction may include the power correction according to the embodiments described with reference to FIGS.

[0408] In one aspect, the power correction in step S1900 includes a step of transmitting a plurality of received power packets related to the power correction from the wireless power receiving device to the wireless power transmitting device, and a step of the wireless power transmitting device performing multiple correction using the power correction data from the plurality of received power packets. As an example, if the number of received power packets is two, the multiple correction is a two-point correction. In the case of the two-point correction, the correction curve or power transmission characteristic derived in step S1900 is as shown in FIG. 18. As another example, if the number of received power packets is three, the multiple correction is a three-point correction. In the case of the three-point correction, the correction curve or power transmission characteristic derived in step S1900 is as shown in FIG.

[0409] The wireless power receiving device transmits a first received power packet, with the mode field set to '000'b or '100'b (general value), to the wireless power transmitting device (S1905). The wireless power transmitting device performs FOD based on the first received power packet to check for the presence of a foreign object (S1910). If no foreign object is detected, the wireless power transmitting device transmits an ACK response to the first received power packet to the wireless power receiving device (S1915). If the wireless power receiving device determines that no foreign object is present based on the ACK response, it transmits a renegotiation packet to the wireless power transmitting device (S1920). In one aspect, a wireless power receiving device that supports authentication may request renegotiation after verifying that the wireless power transmitting device supports authentication and confirming that it is an authenticated wireless power transmitting device. The wireless power receiving device requests renegotiation to update an existing power contract (e.g., increase to a higher power) by transmitting the renegotiation packet. During the renegotiation phase, the wireless power transmitting device and the wireless power receiving device may renew the power contract. At this time, the power contract can be updated to a higher power requirement (GP) (ie, greater than 5W) than the existing power.

[0410] After the renegotiation step, the wireless power receiving device transmits a second received power packet with the mode field set to '010'b to the wireless power transmitting device (S1925). That is, the second received power packet is related to power adjustment, and upon receiving the second received power packet, the wireless power transmitting device can perform power adjustment again under the requested power (or target power) updated by the renegotiation.

[0411] If the mode field is found to be '010', the wireless power transmitting apparatus stores the received power value indicated by the second received power packet in memory and performs power correction. Through the power correction, for example, a power transmission characteristic (or correction curve) such as that shown in FIG. 19 can be derived. That is, if the power correction data (light load transmission power (Ptr_light), light load correction value (Prec_light), first connected load transmission power (Ptr_connected(1))), first connected load correction value (Prec_connected(1)), second connected load transmission power (Ptr_connected(2))), and second connected load correction value (Prec_connected(2))) are expressed in the form of coordinates (x, y) consisting of pairs of transmission power and reception power, when the first coordinate (Ptr_light, Prec_light), second coordinate (Ptr_connected(1), Prec_connected(1)), and third coordinate (Ptr_connected(2), Prec_connected(2)) are derived, a power transmission characteristic or correction curve with different slopes for each section can be derived as shown in FIG. 19.

[0412] Alternatively, steps S1920 and S1925 may be repeatedly executed.

[0413] Thereafter, when the wireless power receiving device receives a received power packet indicating a general value (e.g., mode field = '000'b) Preceived, not a received power packet related to power correction (e.g., mode field = '001'b or '010b'), for the power Ptransmitted transmitted by the wireless power transmitting device (S1930), the wireless power transmitting device performs foreign object detection based on the transmitted power Ptransmitted and the received power Preceived (S1935). For example, step S1935 may include the wireless power transmitting device performing foreign object detection based on power loss as shown in FIG. 20.

[0414] Meanwhile, other embodiments include a wireless power transmitting apparatus and method, and a wireless power receiving apparatus and method, that perform power correction associated with an authentication procedure.

[0415] For example, a wireless power receiving apparatus that supports authentication may adaptively perform power correction depending on whether a wireless power transmitting apparatus is authenticated or the authentication progress stage.

[0416] For example, this embodiment includes a wireless power receiving device and method that perform a step of performing power correction using a connected load corresponding to a basic power profile (BPP or 5W) when entering an initial power transmission step, a step of verifying that the wireless power transmitting device supports a certified (e.g., Qi-certified) extended power profile (EPP or 5W or more), a step of entering into a power transmission contract at a desired target power value (e.g., 8W or 15W) if the verification result and authentication are successfully performed, and a step of transmitting a received power packet for power correction under the connected load condition to the wireless power transmitting device.

[0417] Thus, the wireless power transmitter is controlled to perform additional power correction. Here, the step of establishing a power transmission contract at a target power value (e.g., 8 W or 15 W) can be performed in the renegotiation step. When the wireless power transmitter receives the received power packet (RP / 1) under a light load condition or the received power packet (RP / 2) under a connected load condition, the wireless power transmitter can transmit an ACK signal to RP(1) or RP(2) to notify the wireless power receiver that the power correction operation has been successfully performed when controlled at a desired operating point by referring to the control error packet value.

[0418] The wireless power transmission apparatus in the embodiment of Fig. 21 corresponds to the wireless power transmission apparatus, wireless power transmitter, or power transmission unit disclosed in Figs. 1 to 15. Therefore, the operation of the wireless power transmission apparatus in this embodiment is implemented by one or a combination of two or more of the components of the wireless power transmission apparatus in Figs. 1 to 15. For example, in this embodiment, the operation of transmitting wireless power may be performed by the power conversion unit 110. Also, in this embodiment, the operation of receiving a received power packet, the operation of performing power correction, the operation of deriving or calculating power transmission characteristics, the operation of performing FOD, etc. may be performed by the communication / control unit 120.

[0419] 21 corresponds to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power receiving apparatus in this embodiment is implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of receiving wireless power may be performed by the power pickup unit 210. In addition, in this embodiment, the operation of generating and transmitting a received power packet, the operation of performing power correction, the operation of performing FOD, etc. may be performed by the communication / control unit 220.

[0420] As described above, when entering the power transmission stage, the wireless power transmitter and the wireless power receiver perform initial power correction using RP / 1 and RP / 2. Thereafter, if the wireless power receiver increases the load power to RP / 2 or more, it can perform additional power correction. However, if the wireless power transmitter supports an additional power correction mode (e.g., WPC ver. 1.3 or later), the wireless power receiver can transmit an RP / 2 packet for additional power correction to the wireless power transmitter. Here, whether the wireless power transmitter supports additional power correction can be confirmed by the version number of the standard supported by the wireless power transmitter. For example, a WPC Qi wireless power transmitter can support additional power correction only in ver. 1.3 or later. Meanwhile, for a wireless power transmitter supporting a higher version (e.g., WPC ver. 1.3 or later), the wireless power receiver can transmit the RP / 2 packet for additional power correction by indicating it as RP / 3 as shown in Table 5 to distinguish it from the existing RP / 2.

[0421] Power correction by changing coupling and / or inserting foreign objects (1)

[0422] The position of the wireless power receiving device may be changed by a user's will or independently of the user's will. Such a change in the position of the wireless power receiving device eventually causes a change in coupling between the wireless power transmitting device and the receiving device. For example, if the transmitting power is increased but the receiving power does not increase correspondingly, this may be due to a coupling change or the insertion of a foreign object. Alternatively, if the control error (CE) suddenly changes after the CE converges to zero without any intentional change to the load of the wireless power receiving device, this may be due to a coupling change or the insertion of a foreign object. The wireless power transmitting device cannot distinguish between the insertion of a foreign object and the coupling change during the power transmission phase. When the wireless power transmitting device detects any phenomenon related to the coupling change or the insertion of a foreign object, the wireless power transmitting device can restart the foreign object detection procedure from the beginning.

[0423] When the coupling is changed, the existing power correction is no longer valid because the power transmission characteristics at light load / connected load depend on the specific coupling conditions, i.e., the power transmission characteristics derived under specific coupling conditions are no longer valid when the corresponding coupling conditions are changed.

[0424] Hereinafter, a method for detecting a coupling change and / or a foreign object insertion, and a method for re-executing FOD and / or performing power correction in response to the coupling change and / or the foreign object insertion will be described in more detail. For convenience of explanation, the coupling change and / or the foreign object insertion will be referred to as a coupling change. The operation of the wireless power transmitting apparatus and the receiving apparatus according to this embodiment can be represented by a flowchart as shown in FIG. 22.

[0425] FIG. 22 is a flowchart illustrating the operation of a wireless power transmitting device and a wireless power receiving device based on coupling change according to an embodiment.

[0426] 22, a wireless power transmitting apparatus transmits wireless power to a wireless power receiving apparatus in a power transmitting step (S2000). In the power transmitting step, the wireless power receiving apparatus transmits a received power packet (RPP) and a control error packet (CEP) to the wireless power transmitting apparatus (S2005).

[0427] The wireless power transmitting device monitors information regarding the power transmitted in the power transmission step and / or information (or packets) received from the wireless power receiving device, and detects the occurrence of a coupling change based on the monitoring results (S2010).

[0428] For example, if the transmitted power (Ptransmitted) increases without an increase in the received power, the wireless power transmitting device may determine that a coupling change event has occurred or that a foreign object has been inserted.

[0429] As another example, if the CE suddenly changes even though there is no intentional load change in the wireless power receiving device while receiving RP / 0 after the control error (CE) has converged to approximately 0, the wireless power transmitting device may determine that a coupling change event has occurred or that a foreign object has been inserted. In this case, the wireless power transmitting device may check whether the change in CE is due to an intentional change in load conditions in the wireless power receiving device through the mode field of the received power packet (RPP). That is, the wireless power transmitting device may determine whether a coupling change event has occurred based on the CEP and RPP.

[0430] In step S2010, if a coupling change (or foreign object insertion) is detected, the wireless power transmitter performs the entire FOD procedure again (Q-factor based FOD and APLD) to detect the foreign object or performs power correction, where the power correction includes an operation of renewing the power correction set before the coupling change.

[0431] The wireless power transmitting device may perform an operation of transmitting a specific bit pattern response to the wireless power receiving device in response to the received power packet received in step S2005 to notify the wireless power receiving device that a coupling change has occurred (S2015).

[0432] FSK modulation can be used to transmit the bit pattern response. For example, the bit pattern response is 8 bits and is called ATN (attention) or RFC (request for communication). The wireless power transmitting apparatus sets a specific bit value in the bit pattern response and transmits it to the wireless power receiving apparatus to request the wireless power receiving apparatus to transmit a DSR (Poll) packet, request the wireless power receiving apparatus to transmit a power-related packet, attract the attention of the wireless power receiving apparatus, request the transmission of a specific packet (e.g., an EPT packet), or provide a response to a packet received from the wireless power receiving apparatus. Here, the power-related packet is an EPT packet or a re-ping start packet. If the power-related packet is an EPT packet, the EPT packet can include EPT / rst (0x0B).

[0433] For example, an ACK response indicating a request acknowledgement may be represented by a bit pattern of '11111111', a NAK response rejecting a request may be represented by a bit pattern of '00000000', and an ND response indicating an unrecognized or invalid request may be represented by a bit pattern of '01010101'. Additionally, the ATN may be defined as various 8-bit bit patterns excluding the bit patterns defined for the ACK / NAK / ND responses. For example, the ATN may be defined as '00001111', '11110000', '10101010', '10110110', '00110011', or '01001001'. However, this is merely an example, and the ATN may be configured with various bit patterns.

[0434] The ATN bit pattern response generally notifies the wireless power receiving device that the wireless power transmitting device has a message to send. Therefore, after receiving the ATN bit pattern response, the wireless power receiving device transmits a DSR (poll) packet to the wireless power transmitting device to determine the specific reason why the wireless power transmitting device sent the ATN bit pattern response (S2020).

[0435] At this time, the wireless power transmitter induces a re-ping or an EPT by transmitting a power-related request packet to the wireless power receiver in response to the DSR (poll) packet (S2025). This is to perform power adjustment due to the coupling change again. Step S2025 corresponds to an operation in which the wireless power transmitter requests the wireless power receiver to re-ping or suspend power transmission. For example, the power-related request packet is a packet transmitted by the wireless power transmitter to the wireless power receiver, and is also referred to as an end power transfer request (EPTR) packet. In one aspect, the power transmission suspend request packet may have the same structure as the EPT packet transmitted by the wireless power receiver to the wireless power transmitter. For example, the power transmission suspend request packet may indicate the following values:

[0436] 0x00―EPT / nul―use if none of the other codes is appropriate.

[0437] 0x01―EPT / cc―charge complete; use to indicate that the battery is full.

[0438] 0x02―EPT / if―internal fault;use if an internal logic error has been encountered.

[0439] 0x03―EPT / otover temperature; use if(eg)the battery temperature exceeds a limit.

[0440] 0x04―EPT / ov―over voltage;use if a voltage exceeds a limit.

[0441] 0x05―EPT / oc―over current; use if the current exceeds a limit.

[0442] 0x06―EPT / bf―battery failure;use if the battery cannot be charged.

[0443] 0x08―EPT / nr―no response;use if the target operating point cannot be reached.

[0444] 0x0A―EPT / an―aborted negotiation;use if a suitable Power Transfer Contract cannot be negotiated.

[0445] 0x0B―EPT / rst―restart;use to restart the power transfer.

[0446] 0x0C―EPT / rep―re-ping;use to restart the power transfer after a specified delay(the re-ping delay).

[0447] In this embodiment, the value of the power transmission interruption request packet can indicate restart or reping. Since the initiator of the reping or power transmission interruption is the wireless power receiving apparatus, the wireless power transmitting apparatus cannot arbitrarily initiate the reping or power transmission interruption without the permission of the wireless power receiving apparatus. Therefore, a process of requesting the wireless power receiving apparatus, which is the initiator of the reping or power transmission interruption, to reping or power transmission interruption is first performed in step S2025.

[0448] Upon receiving the request for a re-ping or a power-related packet, the wireless power receiving apparatus transmits an ACK to the wireless power transmitting apparatus as a response to the power-related request packet (S2030) and transmits the power-related packet to the wireless power transmitting apparatus (S2035). Here, the power-related packet is also referred to as a re-ping start packet. For example, the power-related packet is an end power transfer (EPT) packet, and the EPT packet can be set to a value indicating a re-ping (e.g., '0x0D' or '0x0C')) or a value indicating a restart of power transmission (e.g., '0x0B'). The re-ping can be performed after a predetermined re-ping delay. In this case, the re-ping delay value can be set by a re-ping time (or delay) packet during the negotiation phase (e.g., when the value of the EPT packet is '0x0C'). Alternatively, the re-ping can be performed immediately during the negotiation phase, regardless of a specific re-ping delay time pre-set by a re-ping time (or delay) packet, etc. (e.g., if the value of the EPT packet is '0x0D' or '0x0E').

[0449] Upon receiving the power-related packet, the wireless power transmitting apparatus resets the wireless power receiving apparatus according to a value indicated by the power-related packet and performs Q measurement and foreign object detection again (S2040). Even if wireless power is not supplied to the wireless power receiving apparatus during the process of performing step S2040, the wireless power receiving apparatus can display on a user interface that it is charging. The foreign object detection in step S2040 may correspond to a foreign object detection operation before power transmission. If the wireless power transmitting apparatus fails to receive a power-related packet within a certain time period in step S2035, the wireless power transmitting apparatus may reset the wireless power receiving apparatus and perform the entire FOD procedure again.

[0450] In this case, the wireless power transmitting device can suppress the step of transmitting an analog PING signal in the selection step and the step of detecting and identifying the wireless power receiving device (at this time, a beep signal indicating detection / identification can be output).

[0451] At this time, power correction may be performed again. In this case, this embodiment may include the wireless power transmitting apparatus again performing foreign object detection through Q measurement and new power correction. In this case, the new power correction may include the power correction described in the embodiments of FIGS. 16 to 21. The new power correction of the wireless power transmitting apparatus may include the power correction operation of the wireless power transmitting apparatus according to the embodiments of FIGS. 16 to 21, and the new power correction of the wireless power receiving apparatus may include the power correction operation of the wireless power receiving apparatus according to the embodiments of FIGS. 16 to 21. As a result, additional power correction due to coupling change is completed, and power correction data, such as a corrected transmission power value and / or a corrected received power value, may be derived based on the new power correction.

[0452] 22 corresponds to the wireless power transmitting apparatus, wireless power transmitter, or power transmitting unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power transmitting apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power transmitting apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of transmitting wireless power to the wireless power receiving apparatus in step S2000 of transmitting power may be performed by the power conversion unit 110. Also, the operation of receiving RPP, CEP, etc. in step S2005, the operation of detecting a coupling change in step S2010, the operation of transmitting a power-related request packet in step S2025, the operation of receiving a power-related packet in step S2035, and the operation of performing Q measurement and FOD in step S2040 may be performed by the communication / control unit 120.

[0453] 22 corresponds to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power receiving apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of receiving wireless power from the wireless power transmitting apparatus in step S2000 may be performed by the power pickup unit 210. Also, the operation of generating and transmitting packets such as RPP and CEP in step S2005, the operation of detecting a coupling change in step S2010, the operation of receiving a power-related request packet in step S2025, and the operation of generating and transmitting a power-related packet in step S2035 may be performed by the communication / control unit 220.

[0454] The power correction method shown in Fig. 22 is an example of a case where the wireless power receiving apparatus is the initiator of the re-ping. However, for immediate re-ping, the wireless power transmitting apparatus may also be the initiator of the re-ping. Therefore, the following describes a power correction method when the wireless power transmitting apparatus is the initiator of the re-ping.

[0455] FIG. 23 is a flow chart illustrating a power correction method based on coupling change according to another embodiment.

[0456] 23, steps S2100 to S2120 are the same as steps S2000 to S2020, respectively. However, in the embodiment of FIG. 23, since the wireless power transmitting apparatus is the initiator of the re-PING, the wireless power transmitting apparatus transmits a power-related packet (S2125) instead of transmitting a power-related request packet to the wireless power receiving apparatus, receives an ACK (ACK) from the wireless power receiving apparatus (S2130), and proceeds to the power correction step. The power-related packet in step S2125 is, for example, 1 byte (8 bits) and may have the format of the re-PING packet as shown in FIG. 24.

[0457] FIG. 24 illustrates a format of a re-PING packet according to an example.

[0458] 24, the re-ping packet has a packet structure including 2 reserved bits (reserved) and a field (e.g., 6 bits) indicating re-ping time information. The re-ping time information is a natural number between 1 and 64 and is used to calculate the re-ping time Tre-ping. For example, the re-ping time Tre-ping = (re-ping time information) x 0.2 seconds. Therefore, the re-ping time is 0.2 seconds, 0.4 seconds, ..., 12.6 seconds. Of course, the number of bits included in the reserved bits and the field indicating the re-ping time can be variously modified.

[0459] 23, the wireless power transmitter may perform the entire FOD procedure again (Q-factor based FOD and APLD) to detect a foreign object or perform power correction (S2135). The foreign object detection in step S2135 may correspond to a foreign object detection operation before power transmission. For example, re-executing the FOD procedure includes a process in which the wireless power transmitter removes power and restarts from Q measurement to the digital PING step. For another example, the power correction may include an operation of renewing the power correction set before the coupling change.

[0460] While the re-PING is being performed, the wireless power transmitting device can suppress the steps of transmitting an analog PING signal in the selection step and the step of detecting and identifying the wireless power receiving device (at this time, a beep signal indicating detection / identification can be output).

[0461] If the wireless power receiving device receives the digital PING signal earlier or later than the re-PING time, this may indicate that the wireless power receiving device placed on the wireless power transmitting device has been replaced by the user, and therefore the wireless power receiving device may execute a default UX (a beep signal or a message instructing the user to start wireless charging).

[0462] 23 corresponds to the wireless power transmitting apparatus, wireless power transmitter, or power transmitting unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power transmitting apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power transmitting apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of transmitting wireless power to the wireless power receiving apparatus in step S2100 may be performed by the power conversion unit 110. Also, the operation of receiving RPP, CEP, etc. in step S2105, the operation of detecting coupling change and / or foreign object insertion in step S2110, the operation of generating and transmitting a bit pattern response in step S2115, the operation of receiving a DSR packet in step S2120, the operation of transmitting a power-related packet in step S2125, the operation of receiving an ACK response in step S2130, and the operation of performing Q measurement and FOD or power correction in step S2135 may be performed by the communication / control unit 120.

[0463] 23 corresponds to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power receiving apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of receiving wireless power from the wireless power transmitting apparatus in step S2100 may be performed by the power pickup unit 210. Also, the operation of generating and transmitting packets such as RPP and CEP in step S2105, the operation of receiving a bit pattern response in step S2115, the operation of generating and transmitting a DSR packet in step S2120, the operation of receiving a power-related packet in step S2125, and the operation of transmitting an ACK in step S2130 may be performed by the communication / control unit 220.

[0464] Power correction due to load change (2): Using RP / 3

[0465] FIG. 25 is a flow diagram illustrating a method for performing power correction and foreign object detection according to one embodiment.

[0466] 25, the wireless power receiving apparatus receives and measures transmission power (hereinafter referred to as first light-load transmission power; Ptr_light) from the wireless power transmitting apparatus under a light-load condition, and then transmits a first received power packet (RPP) indicating the received power value under the light-load condition to the wireless power transmitting apparatus (S2300). The first received power packet may have, for example, the format shown in FIG. 17. In addition, the mode field indicates how to interpret the received power value, and an example of the mode field is shown in Table 5.

[0467] [Table 5]

[0468] Referring to Table 5, when the mode field is '000', it indicates that the received power value is a general power value (which can be represented by RP / 0), and when the mode field is '001', '010', or '011', it indicates that the received power packet is related to power calibration (which can be represented by RP / 1, RP / 2, or RP / 3, respectively). That is, the wireless power receiving apparatus can indicate power calibration by transmitting a received power packet with the mode field = '001', '010', or '011' to the wireless power transmitting apparatus. Specifically, when the mode field is '001' (i.e., RP / 1), the received power packet can indicate the power value (hereinafter referred to as the light-load calibration value, Prec_light) received by the wireless power receiving apparatus when the wireless power receiving apparatus is in a light-load condition. Also, if the mode field = '010' (i.e., RP / 2), the received power packet may indicate the power value (hereinafter referred to as the connected-load calibration value, Prec_connected) received by the wireless power receiving device when the wireless power receiving device is in a connected-load condition. Also, if the mode field = '011' (i.e., RP / 3), it may indicate that the received power packet is associated with a multi-point connected-load calibration value. The light load condition may mean a condition in which no load (e.g., a battery) is electrically connected to the wireless power receiving device, and the connected load condition may mean a condition in which a load is connected to the wireless power receiving device.

[0469] When the wireless power transmitter and the wireless power receiver enter the power transmission stage, they perform initial power correction using RP / 1 and RP / 2. If the wireless power receiver subsequently increases the load power to more than RP / 2, additional power correction is required. Therefore, the wireless power receiver transmits RP / 3 to the wireless power transmitter, enabling the wireless power transmitter to perform additional power correction.

[0470] Here, if the wireless power transmitter supports an additional power correction mode (e.g., WPC ver. 1.3 or later), the wireless power receiver can transmit an RP / 3 packet for additional power correction to the wireless power transmitter. Whether the wireless power transmitter supports additional power correction can be determined, for example, by the version number of the standard supported by the wireless power transmitter. That is, the WPC Qi wireless power transmitter can support additional power correction only in ver. 1.3 or later.

[0471] Referring again to FIG. 25 , the first received power packet indicates a received power value measured under a light load condition (i.e., a light load correction value, Prec_light), so the mode field of the first received power packet is set to '001' (i.e., RP / 1). Therefore, step S2300 may further include the wireless power receiving apparatus setting the mode field to '001'. Upon determining that the mode field is '001', the wireless power transmitting apparatus identifies that the received power value indicated by the first received power packet is the light load correction value (Prec_light). The wireless power transmitting apparatus may store the light load correction value (Prec_light) in a memory to perform power correction. Although not shown in the drawing, the wireless power transmitting apparatus may transmit an ACK or NAK to the wireless power receiving apparatus in response to the first received power packet. In addition, the first received power packet may be transmitted multiple times or continuously. In this case, the first received power packet (ie, RP / 1) transmitted consecutively is treated as one received power packet (ie, a single RP / 1).

[0472] In one aspect, when receiving RP / 1, the wireless power transmitting device transmits a NAK (while monitoring the CE value) until the wireless power receiving device stably reaches the corresponding power level, and after the power level stabilizes, transmits an ACK and takes the RP1 value at that time.

[0473] After the wireless power receiving device receives and measures the first connected-load transmission power (Ptr_connected(1)) from the wireless power transmitting device under the first connected-load condition, it transmits a second received power packet (i.e., RP / 2) that indicates the first connected-load correction value (Prec_connected(1)) to the wireless power transmitting device (S2305).

[0474] Step S2305 can further include the step where the wireless power receiving device sets the mode field = '010'. When it is confirmed that the mode field = '010', the wireless power transmitting device identifies that the received power value indicated by the second received power packet is the first connected-load correction value (Prec_connected(1)). The wireless power transmitting device can store the first connected-load correction value (Prec_connected(1)) in the memory to perform power correction.

[0475] Based on RP / 1 and RP / 2, for example, the power transmission characteristics or correction curves according to FIGS. 18 and Equations 1 to 2 can be derived.

[0476] The wireless power receiving device changes the connected load (S2310). The change in the connected load can include an increase or a decrease in the connected load. The change in the connected load can mean that the target rectifying voltage (target Vrec) or the target power of the wireless power receiving device increases or decreases compared to the previous connected load. The situation where the connected load is changed can include the case where the wireless power receiving device uses multiple load steps to reach the target power. When the connected load is changed, at least a part of the previously set power transmission characteristics can be changed, or additional power transmission characteristics can be set while maintaining the previously set power transmission characteristics. For example, when the transmission power Ptr increases to the range where Ptr_connected(1) < Ptr due to an increase in the connected load, the power transmission characteristics in FIG. 18 cannot cover this situation.

[0477] Therefore, to reflect the changed state of the connected load in the power correction and improve foreign object detection performance, the wireless power transmitter and / or receiver performs multi-point power correction. To do this, additional power correction data is required. To do this, the wireless power receiver receives and measures a second connected load transmission power (Ptr_connected(2)) from the wireless power transmitter under a second connected load condition, and then transmits a third received power packet (RP / 3) indicating a second connected load correction value (Prec_connected(2)) to the wireless power transmitter (S2315). If the wireless power transmitter responds with an ACK in response to the second received power packet (RP / 2) in step S2310, additional RP / 2 transmission from the wireless power receiver may not be permitted. However, to improve power loss-based foreign object detection performance, the restriction on the timing of power correction may be removed, and multi-point power correction of two or more points may be required. Therefore, transmission of the third received power packet may be permitted as in step S2325.

[0478] Step S2325 may further include the wireless power receiving device setting the mode field to '011'. If the wireless power transmitting device determines that the mode field is '011', the wireless power transmitting device identifies that the received power value indicated by the third received power packet is a multi-point correction value (Prec_connected(2)) under the second connected load condition. Because the mode field is '011', the wireless power transmitting device can know that additional power correction is required.

[0479] As an example related to the transmission timing of RP / 3, the transmission of RP / 3 can be performed at any time when the wireless power receiving device steps up the target load power. That is, at the start of the power transmission step, an initial power correction is performed based on RP / 1 and RP / 2 (steps S2300 to S2310), and after the initial power correction, a multi-point power correction can be performed at any time when the wireless power receiving device steps up the target load power.

[0480] As another example related to the transmission timing of RP / 3, the wireless power receiving device may transmit RP / 3 between multiple RP / 0s or between multiple RP / 0s and a CEP during a power transmission phase, where the transmission of RP / 3 may be performed at any time when the wireless power receiving device steps up the target load power.

[0481] The wireless power transmitting apparatus can store the second connected load correction value (Prec_connected(2)) in a memory to perform multi-point power correction.

[0482] Based on the power correction data obtained through steps S2300, S2305, and S2325, power transmission characteristics can be derived or set. The derived power transmission characteristics are, for example, as shown in FIG.

[0483] Thereafter, when the wireless power receiving device receives a fourth received power packet (i.e., RP / 0) indicating a general value (e.g., Mode field = '000'b) Preceived, not a received power packet related to power correction (e.g., Mode field = '001'b or '010b'), for the power Ptransmitted transmitted by the wireless power transmitting device (S2330), the wireless power transmitting device completes the power correction and performs foreign object detection based on the transmitted power Ptransmitted and the received power Preceived (S2335). For example, step S2335 may include the wireless power transmitting device performing foreign object detection based on power loss as shown in FIG. 20.

[0484] Although not shown in the drawings, the wireless power transmitter can transmit an ACK or NAK to the wireless power receiver in response to RP / 1, RP / 2, and RP / 3. The wireless power transmitter can repeat the operation of transmitting a NAK to the wireless power receiver until control is performed at a desired operating point. In addition, the wireless power receiver can transmit one or more CE packets between all received power packets, including RP / 1, RP / 2, and RP / 3.

[0485] For example, in the embodiment of FIG. 25, the wireless power receiving apparatus transmits a first received power packet (RP / 1) to the wireless power transmitting apparatus (S2300). However, if the corresponding power level cannot be reached, the wireless power transmitting apparatus transmits a NAK to the wireless power receiving apparatus. In this case, the wireless power transmitting apparatus checks one or more CE packets transmitted from the wireless power receiving apparatus while changing the operating point, and determines whether the wireless power receiving apparatus has reached the desired operating point. This process (RP / 1(NAK)-CE-CE-CE-CE-RP1(NAK)-CE-CE-CE) is repeated, and when the power level stabilizes, the wireless power transmitting apparatus transmits an ACK and takes the RP / 1 value at that time as power correction data.

[0486] Upon receiving an ACK in response to the first received power packet (RP / 1), the wireless power receiving apparatus transmits a second received power packet (RP / 2) to the wireless power transmitting apparatus (S2305). However, if the corresponding power level cannot be reached, the wireless power transmitting apparatus transmits a NAK to the wireless power receiving apparatus. In this case, the wireless power transmitting apparatus checks one or more CE packets transmitted from the wireless power receiving apparatus while changing the operating point, and determines whether the wireless power receiving apparatus has reached the desired operating point. This process (RP / 2(NAK)-CE-CE-CE-CE-RP2(NAK)-CE-CE-CE) is repeated, and when the power level stabilizes, the wireless power transmitting apparatus transmits an ACK and takes the RP / 2 value at that time as a power correction parameter.

[0487] Thereafter, the wireless power receiving apparatus transmits a third received power packet (RP / 3) to the wireless power transmitting apparatus in response to a change in the connected load (S2310) (S2325). However, if the corresponding power level cannot be reached, the wireless power transmitting apparatus transmits a NAK to the wireless power receiving apparatus. In this case, the wireless power transmitting apparatus checks one or more CE packets transmitted from the wireless power receiving apparatus while changing the operating point, and determines whether the wireless power receiving apparatus has reached the desired operating point. This process (RP / 3(NAK)-CE-CE-CE-CE-RP3(NAK)-CE-CE-CE) is repeated. When the power level stabilizes, the wireless power transmitting apparatus transmits an ACK and takes the RP / 3 value at that time as power correction data.

[0488] Thereafter, when the wireless power receiving device receives a received power packet indicating a general value (e.g., mode field = '000'b) Preceived, not a received power packet related to power correction (e.g., mode field = '001'b or '010b') (S2330), the wireless power transmitting device corrects Preceived based on the power correction, calculates the power loss, and performs foreign object detection based on the power loss (S2335).

[0489] The wireless power transmission apparatus in the embodiment of Fig. 25 corresponds to the wireless power transmission apparatus, wireless power transmitter, or power transmission unit disclosed in Fig. 1 to Fig. 15. Therefore, the operation of the wireless power transmission apparatus in this embodiment is implemented by one or a combination of two or more of the components of the wireless power transmission apparatus in Fig. 1 to Fig. 15. For example, in the above embodiment, the power correction process, ACK / NAK transmission, and / or RP and CEP reception operations by the wireless power transmission apparatus may be performed by the communication / control unit 120.

[0490] 25 corresponds to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power receiving apparatus in this embodiment is implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in FIGS. 1 to 15. For example, in the above embodiment, the power correction process, RP and CEP transmission, and / or ACK / NAK reception operations by the wireless power receiving apparatus may be performed by the communication / control unit 220.

[0491] Other embodiments of the present invention include a wireless power transmission apparatus and method, and a wireless power reception apparatus and method, that perform power correction in connection with an authentication procedure. That is, multi-point power correction can be performed in connection with authentication.

[0492] For example, a method for performing multi-point power correction for a wireless power receiving device without authentication function may include the steps of performing initial power correction using RP / 1 and / or RP / 2 at an intermediate power level (e.g., basic power profile (BPP) or 5W) when the wireless power transmitting device and the receiving device enter an initial power transmission stage, the wireless power transmitting device performing power transmission at the intermediate power level, and the wireless power receiving device continuously transmitting RP / 3 packets to the wireless power transmitting device after the initial power correction to gradually increase the load power to a target load power. Here, the wireless power receiving device may perform foreign object detection with no power correction or only partial power correction. Also, the wireless power receiving device may transmit RP / 0 while maintaining the power level.

[0493] As another example, a method for performing multi-point power correction for a wireless power receiving device without authentication function may include the steps of performing initial power correction using RP / 1 and / or RP / 2 at an intermediate power level (e.g., basic power profile (BPP or 5W)) when the wireless power transmitting device and the receiving device enter an initial power transmission stage, the wireless power transmitting device performing power transmission at the intermediate power level, and transmitting RP / 0 to the wireless power transmitting device while the wireless power receiving device maintains a target load power, and the wireless power receiving device transmitting an RP / 3 packet to the wireless power transmitting device at any appropriate time after the initial power correction to gradually increase the load power. Here, the wireless power receiving device may perform foreign object detection with no power correction or only partial power correction.

[0494] As another example, a method for performing multi-point power correction for a wireless power receiving device performing an authentication function may include the steps of performing initial power correction based on RP / 1 and / or RP / 2 at an intermediate power level (e.g., BPP or 5W) when the wireless power transmitting device and the receiving device enter an initial power transmission stage, performing authentication while the wireless power transmitting device and / or the receiving device transmit power at the intermediate power level, and, after successful authentication, transmitting an RP / 3 packet to the wireless power transmitting device to gradually increase the load power. Here, the performing authentication may further include verifying that the certified (e.g., Qi-certified) Extended Power Profile (EPP or 5W or higher) is supported, and, if the verification result indicates successful authentication, entering into a power transmission contract for a desired target power value (e.g., 8W or 15W). Also, the wireless power receiving device may transmit an RP / 0 packet to the wireless power transmitting device while authentication is in progress.

[0495] Accordingly, the wireless power transmitting device is controlled to perform additional power correction. Here, the step of establishing a power transmission contract for a target power value (e.g., 8 W or 15 W) can be performed in the renegotiation step. That is, after the authentication completion and renegotiation steps, the wireless power receiving device can increase the target power. In this case, the wireless power receiving device performs additional power correction by transmitting RP / 3 to the wireless power transmitting device.

[0496] Power correction by changing coupling and / or detecting foreign objects (2): Using EPT / fod

[0497] When a wireless power transmission device performs foreign object detection using the RP / 0 value, it is not possible to clearly distinguish between changes caused by the insertion of an actual foreign object and changes caused by the user moving the wireless power receiving device. Therefore, the wireless power transmission device can re-perform foreign object detection using the Q and resonance value and interrupt power transmission only when an actual foreign object is detected.

[0498] Therefore, a method for preventing false foreign object detection by redoing pre-power foreign object detection when a foreign object is inserted midway or a coupling change is also required. This method can be performed based on an interrupt power transmission (EPT) packet.

[0499] A method for performing foreign object detection according to one embodiment includes a step in which a wireless power transmitting device and / or a wireless power receiving device monitors RP / 0 and / or CEP, a step in which the wireless power transmitting device and / or the receiving device detects the occurrence of a specific event, a step in which the wireless power receiving device transmits an EPT packet (EPT / fod) for FOD to the wireless power transmitting device, and a step in which the wireless power transmitting device performs FOD based on the EPT packet.

[0500] Here, the specific event may include, for example, a case where a foreign object is inserted during the power transmission step, or a case where the wireless power receiving device is moved due to an external influence, causing a change in coupling.

[0501] The EPT packet for FOD generated by the wireless power receiving apparatus is, for example, EPT / fod, EPT / rst, or EPT / rep (0x0B—EPT / rst—restart; use to restart the power transfer / 0x0C—EPT / rep—re-ping; use to restart the power transfer after a specified delay (the re-ping delay)). Such an EPT packet for FOD may have a structure as shown in FIG. 17 and may indicate one of the values ​​in Table 6 below.

[0502] [Table 6]

[0503] Here, EPT / fod can indicate the reason for FOD and additional power correction before power transmission. That is, the wireless power receiving device can use the EPT / fod value when it recognizes the need for FOD and additional power correction before power transmission through internal observation. For example, a wireless power transmitting device can determine whether a foreign object is inserted using the corrected power value, and a wireless power receiving device can suspect a foreign object insertion when the received power value or the operating point (e.g., rectified voltage) value ideally changes.

[0504] EPT / rst may cause the wireless power transmitter and / or receiver to generate noise due to restart, which may result in an undesirable experience for the user. EPT / rep may be used to provide users with better wireless charging services. That is, the wireless power receiver may transmit an EPT / rep packet to the wireless power transmitter. In this case, the wireless power transmitter may again measure the Q factor before power transmission (pre-power) and perform foreign object detection through new power correction.

[0505] When a wireless power receiving device uses EPT / rep, there is a problem that the wireless power transmitting device cannot determine the time required for FOD before power transmission. Therefore, it is necessary to define EPT / fod using a new code in the EPT packet. In addition, the wireless power receiving device transmits an EPT / fod packet to a wireless power transmitting device, causing the wireless power transmitting device to suspend power transmission and perform FOD before power transmission. The EPT / fod packet, like the EPT / rep packet, is defined to prevent the wireless power transmitting device and / or receiving device from generating noise.

[0506] A method for performing foreign object detection according to another embodiment includes a step in which a wireless power transmitting device and / or a wireless power receiving device monitors RP / 0 and / or CEP, a step in which the wireless power transmitting device and / or the receiving device detects the occurrence of a specific event, a step in which the wireless power transmitting device transmits an EPT packet (EPT / fod) for FOD to the wireless power receiving device, a step in which the wireless power transmitting device performs FOD based on the EPT packet, and a step in which power transmission is restarted based on the FOD result.

[0507] In one aspect, the EPT packet for FOD generated by the wireless power transmitting apparatus may have the same structure as the EPT packet for FOD generated by the wireless power receiving apparatus as shown in Figure 17. In this case, the EPT packet may indicate one of the values ​​in Table 7 below.

[0508] [Table 7]

[0509] For example, the EPT packet indicates a specific value meaning EPT / fod, where EPT / fod can indicate the FOD before power transmission and the reason for additional power correction. That is, the wireless power transmission device can use the EPT / fod value when it recognizes the need for FOD before power transmission and additional power correction from internal observation.

[0510] In another aspect, an EPT packet for FOD generated by a wireless power transmitting apparatus may have a different structure from an EPT packet for FOD generated by a wireless power receiving apparatus, in which case at least some of the values ​​in Table 8 below indicating the EPT packet may be reused.

[0511] [Table 8]

[0512] Meanwhile, before the step of the wireless power transmitting apparatus transmitting the EPT packet for FOD to the wireless power receiving apparatus, the steps of the wireless power transmitting apparatus transmitting the ATN to the wireless power receiving apparatus, the wireless power receiving apparatus transmitting the CEP to the wireless power transmitting apparatus, and the wireless power receiving apparatus transmitting a DSR / poll to the wireless power transmitting apparatus may be performed. Furthermore, upon receiving the EPT packet for FOD, the wireless power receiving apparatus may transmit a DSR / ACK to the wireless power transmitting apparatus.

[0513] Meanwhile, after restarting power transmission based on the EPT / fod packet, the wireless power transmitter and receiver can immediately enter the power transmission stage if it is determined that there is no foreign object. The method of entering the power transmission stage may differ depending on whether the wireless power transmitter and receiver are attempting to immediately enter the power transmission stage after restarting or whether they are attempting to execute a full protocol. Specifically, the operation of entering the power transmission stage can be defined as follows from the perspective of the wireless power receiver and the wireless power transmitter.

[0514] First, the operation of the wireless power receiving device is as follows.

[0515] For example, when the wireless power receiving device attempts to immediately enter the power transmission phase after restart, it can transmit RP / 0 as the first packet to the wireless power transmitting device. After restart, an initial power correction can be performed in the power transmission phase, and the previous power contract can be effectively preserved.

[0516] As another example, when the wireless power receiving device attempts to execute a full protocol after restarting, it can transmit a signal strength (SS) packet as the first packet to the wireless power transmitting device.

[0517] In this case, after restarting, the wireless power receiving device goes through a digital PING step, an identification and configuration step, and a negotiation step before entering a power transmission step. The wireless power receiving device performs initial power correction by transmitting RP / 1 and RP / 2 when starting power transmission, and thereafter, the wireless power receiving device can perform additional power correction by transmitting RP / 3 every time the target load power is increased.

[0518] Next, the operation of the wireless power transmitting device is as follows.

[0519] The wireless power transmitter may have different procedures for entering the power transmission stage depending on the first packet of the wireless power receiver.

[0520] As an example, when the wireless power transmitting apparatus receives a signal strength (SS) packet as the first packet from the wireless power receiving apparatus, the wireless power transmitting apparatus executes the full protocol.

[0521] FIG. 26 is a flow chart illustrating a method for correcting power based on foreign object insertion or coupling change according to one embodiment.

[0522] 26, a wireless power transmitting apparatus transmits wireless power to a wireless power receiving apparatus in a power transmitting step (S2400). In the power transmitting step, the wireless power receiving apparatus transmits a received power packet (RPP) and a control error packet (CEP) to the wireless power transmitting apparatus (S2405).

[0523] The wireless power transmitting device monitors information regarding the power transmitted in the power transmission step and / or information (or packets) received from the wireless power receiving device, and detects the occurrence of foreign object insertion or coupling change based on the monitoring results (S2410).

[0524] For example, if the transmitted power (Ptransmitted) increases without an increase in the received power, the wireless power transmitting device may determine that a coupling change event has occurred or that a foreign object has been inserted.

[0525] As another example, if the CE suddenly changes without any intentional load change in the wireless power receiving device after the control error (CE) has converged to approximately 0, the wireless power transmitting device may determine that a coupling change event has occurred or that a foreign object has been inserted. In this case, the wireless power transmitting device may check whether the change in CE is due to an intentional change in load conditions in the wireless power receiving device through a mode field in a received power packet (RPP). That is, the wireless power transmitting device may determine whether a coupling change event has occurred based on the CEP and RPP.

[0526] In step S2410, if a coupling change (or foreign object insertion) is detected, the wireless power transmitting apparatus performs the entire FOD procedure again (Q-factor based FOD and APLD) to detect the foreign object or performs power correction, where the power correction includes an operation of renewing the power correction set before the coupling change.

[0527] The wireless power transmitting device may perform an operation of transmitting a specific bit pattern response to the wireless power receiving device in response to the received power packet received in step S2405 to notify the wireless power receiving device that a coupling change has occurred (S2415).

[0528] FSK modulation can be used to transmit the bit pattern response. For example, the bit pattern response is 8 bits and is called ATN (attention) or RFC (request for communication). The wireless power transmitting device can request the wireless power receiving device to transmit a DSR (Poll) packet or an EPT / fod packet by setting a specific bit value in the bit pattern response and transmitting it to the wireless power receiving device.

[0529] For example, an ACK response indicating a request acknowledgement may be represented by a bit pattern of '11111111', a NAK response rejecting a request may be represented by a bit pattern of '00000000', and an ND response indicating an unrecognized or invalid request may be represented by a bit pattern of '01010101'. Additionally, the ATN may be defined as various 8-bit bit patterns excluding the bit patterns defined for the ACK / NAK / ND responses. For example, the ATN may be defined as '00001111', '11110000', '10101010', '10110110', '00110011', or '01001001'. However, this is merely an example, and the ATN may be configured with various bit patterns.

[0530] Since the ATN bit pattern response generally informs the wireless power receiving device that the wireless power transmitting device has a message to send, after receiving the ATN bit pattern response, the wireless power receiving device transmits a DSR (poll) packet to the wireless power transmitting device to determine the specific reason why the wireless power transmitting device sent the ATN bit pattern response (S2420).

[0531] At this time, the wireless power transmitter transmits a packet requesting a re-ping for Q-factor measurement to the wireless power receiver in response to the DSR (poll) packet (S2425). This is to perform power correction again due to coupling change or foreign object insertion. Step S2425 corresponds to an operation in which the wireless power transmitter requests the wireless power receiver to re-ping or suspend power transmission.

[0532] The wireless power receiving device, having received the packet requesting re-PING, transmits a power interruption packet (EPT / fod) for FOD for Q-factor measurement to the wireless power transmitting device (S2430). The EPT packet can be set to a value indicating FOD or a value indicating restart of power transmission (e.g., '0x0B').

[0533] Upon receiving the power interruption packet, the wireless power transmitting apparatus resets the wireless power receiving apparatus according to the value indicated by the power interruption packet and performs Q measurement and foreign object detection (FOD) (S2435). Even if wireless power is not supplied to the wireless power receiving apparatus during the process of performing step S2435, the wireless power receiving apparatus can display on the user interface that it is charging. The foreign object detection in step S2435 may correspond to a foreign object detection operation before power transmission. If the wireless power transmitting apparatus fails to receive the power interruption packet within a certain time period in step S2430, the wireless power transmitting apparatus can reset the wireless power receiving apparatus and perform the entire FOD procedure again.

[0534] In this case, the wireless power transmitting device can suppress the step of transmitting an analog PING signal in the selection step and the step of detecting and identifying the wireless power receiving device (at this time, a beep signal indicating detection / identification can be output).

[0535] At this time, the power correction may be performed again. In this case, the present embodiment may include the step of the wireless power transmitting apparatus again performing foreign object detection through Q measurement and new power correction.

[0536] In this case, the new power correction may include the power correction described in the embodiments of Figures 16 to 21. The new power correction of the wireless power transmitting apparatus may include the power correction operation of the wireless power transmitting apparatus according to the embodiments of Figures 16 to 21, and the new power correction of the wireless power receiving apparatus may include the power correction operation of the wireless power receiving apparatus according to the embodiments of Figures 16 to 21. As a result, additional power correction due to coupling change is completed, and power correction data such as a corrected transmission power value and / or a corrected reception power value according to the new power correction may be derived.

[0537] 26 corresponds to the wireless power transmission apparatus, wireless power transmitter, or power transmission unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power transmission apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power transmission apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of transmitting wireless power to the wireless power receiving apparatus in step S2400 of transmitting power may be performed by the power conversion unit 110. Also, the operation of receiving RPP, CEP, etc. in step S2405, the operation of detecting a coupling change or foreign object insertion in step S2410, the operation of transmitting a re-PING request packet in step S2425, the operation of receiving a power interruption packet in step S2430, and the operation of performing Q measurement and FOD in step S2435 may be performed by the communication / control unit 120.

[0538] 26 corresponds to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power receiving apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of receiving wireless power from the wireless power transmitting apparatus in step S2400 may be performed by the power pickup unit 210. Also, the operation of generating and transmitting packets such as RPP and CEP in step S2405, the operation of receiving a re-PING request packet in step S2425, and the operation of generating and transmitting a power interrupt packet in step S2430 may be performed by the communication / control unit 220.

[0539] FIG. 27 is a flow chart illustrating a method for correcting power based on coupling change or foreign object insertion according to another embodiment.

[0540] 27, steps S2500 to S2520 are the same as steps S2400 to S2420, respectively. However, since the wireless power transmitting apparatus is the initiator of the re-ping in the embodiment of Fig. 27, the wireless power transmitting apparatus transmits a power interrupt packet (S2525) instead of transmitting a power-related request packet to the wireless power receiving apparatus, and receives an ACK from the wireless power receiving apparatus (S2530) to enter the power correction step.

[0541] In step S2525, the EPT packet for FOD generated by the wireless power receiving device is, for example, EPT / fod, EPT / rst, or EPT / rep (0x0B—EPT / rst—restart; use to restart the power transfer; 0x0C—EPT / rep—re-ping; use to restart the power transfer after a specified delay (the re-ping delay)). Here, EPT / fod may indicate the reason for FOD and additional power correction before power transmission. That is, the wireless power receiving device can use the EPT / fod value when it recognizes the need for FOD and additional power correction before power transmission from internal observation.

[0542] EPT / rst may cause the wireless power transmitting device and / or receiving device to generate noise due to restart, which may give the user an undesirable experience. To provide users with better wireless charging services, EPT / rep can be used. That is, the wireless power receiving device can send an EPT / rep packet to the wireless power transmitting device.

[0543] The wireless power transmission apparatus re-executes the entire FOD procedure (Q-factor based FOD and APLD) to detect a foreign object or perform power correction (S2535). For example, re-executing the FOD procedure includes the wireless power transmission apparatus removing power and restarting from Q measurement up to the digital PING stage. For another example, power correction includes an operation of renewing the power correction set before the coupling change.

[0544] While the re-PING is being performed, the wireless power transmitting device can suppress the step of transmitting an analog PING signal in the selection step and the step of detecting and identifying the wireless power receiving device (at this time, a beep signal indicating detection / identification can be output).

[0545] If the wireless power receiving device receives the digital PING signal earlier or later than the re-PING time, this may indicate that the wireless power receiving device placed on the wireless power transmitting device has been replaced by the user, and therefore the wireless power receiving device may execute a default UX (a beep signal or a message instructing the user to start wireless charging).

[0546] The wireless power transmitter and receiver can restart power transmission based on the foreign object detection result. Meanwhile, after restarting power transmission based on the EPT / fod packet, the wireless power transmitter and receiver can immediately enter the power transmission stage if it is determined that there is no foreign object. The method of entering the power transmission stage may differ depending on whether the power transmission stage is to be entered immediately after the restart or whether a full protocol is to be executed. Specifically, the operation of entering the power transmission stage can be defined as follows from the perspective of the wireless power receiver and the wireless power transmitter.

[0547] First, the operation of the wireless power receiving device is as follows.

[0548] For example, when the wireless power receiving device attempts to immediately enter the power transmission phase after restart, it can transmit RP / 0 as the first packet to the wireless power transmitting device. After restart, an initial power correction can be performed in the power transmission phase, and the previous power contract can be effectively preserved.

[0549] As another example, when the wireless power receiving device attempts to execute a full protocol after restart, it can transmit a signal strength (SS) packet as the first packet to the wireless power transmitting device. After restart, an initial power correction can be performed during the power transmission phase, and the previous power contract can be effectively maintained.

[0550] Next, the operation of the wireless power transmitting device is as follows.

[0551] The wireless power transmitter may have different procedures for entering the power transmission stage depending on the first packet of the wireless power receiver.

[0552] As an example, when the wireless power transmitting apparatus receives an SS as the first packet from the wireless power receiving apparatus, the wireless power transmitting apparatus executes the full protocol.

[0553] 27 corresponds to the wireless power transmission apparatus, wireless power transmitter, or power transmission unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power transmission apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power transmission apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of transmitting wireless power to the wireless power receiving apparatus in step S2500 of transmitting power may be performed by the power conversion unit 110. Also, the operation of receiving RPP, CEP, etc. in step S2505, the operation of detecting coupling change and / or foreign object insertion in step S2510, the operation of generating and transmitting a bit pattern response in step S2515, the operation of receiving a DSR packet in step S2520, the operation of transmitting a power interrupt packet in step S2525, the operation of receiving an ACK response in step S2530, and the operation of performing Q measurement and FOD in step S2535 may be performed by the communication / control unit 120.

[0554] 27 corresponds to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 15. Therefore, the operation of the wireless power receiving apparatus in this embodiment may be implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in FIGS. 1 to 15. For example, in this embodiment, the operation of receiving wireless power from the wireless power transmitting apparatus in step S2500 may be performed by the power pickup unit 210. Also, the operation of generating and transmitting packets such as RPP and CEP in step S2505, the operation of receiving a bit pattern response in step S2515, the operation of generating and transmitting a DSR packet in step S2520, the operation of receiving a power interrupt packet in step S2525, and the operation of transmitting an ACK in step S2530 may be performed by the communication / control unit 220.

[0555] Hereinafter, a method for constructing a power correction curve according to another embodiment will be described.

[0556] The power correction curve should represent the charging profile of the wireless power receiving device. In one aspect, the power correction curve can include multiple segments. In another aspect, each segment of the power correction curve represents the charging profile of a specific power range at a specific operating point of the wireless power receiving device.

[0557] Each segment of the power correction curve may be represented by a received power value of the wireless power receiving device. For example, each segment of the power correction curve may be represented by a power level of a first received power (RP / 1), a second received power (RP / 2), and a third received power (RP / 3) of the wireless power receiving device. In one aspect, the initial correction curve is based on two points. Here, the two points may be determined by the first received power (RP / 1) and the second received power (RP / 2). In another aspect, the extended correction curve is based on multiple points (more than two points). Here, the multiple points may be determined by at least two or more of the first received power (RP / 1), the second received power (RP / 2), and the third received power (RP / 3). That is, one or multiple third received powers (RP / 3) may be used to extend the initial correction curve. In another aspect, the relationship RP / 1<=RP / 2<=RP / 3 may hold.

[0558] FIG. 28 shows a power transmission characteristic or correction curve according to another embodiment of the present invention.

[0559] 28, when the wireless power receiving device operates in another operating mode (e.g., when the wireless power receiving device operates at another operating point), it can transmit a first received power packet (RP / 1), a second received power packet (RP / 2), and a third received power packet (RP / 3) to the wireless power transmitting device. That is, when the wireless power receiving device changes its operating point (op.point 1, 2, 3), the wireless power transmitting device can receive the first received power packet (RP / 1), the second received power packet (RP / 2), and the third received power packet (RP / 3) from the wireless power receiving device.

[0560] An example of a time when the wireless power receiving device changes its operating point may include a time when the power transmission phase begins. Another example of a time when the wireless power receiving device changes its operating point may include a time when the operating point is stepped up after a power transmission contract is renegotiated (e.g., after successful authentication). Another example of a time when the wireless power receiving device changes its operating point may include a time when the operating point is stepped down during a power transmission phase.

[0561] The format of the received power packet according to this embodiment is the same as the format shown in Fig. 17. However, the mode field can indicate 0 to 4 as shown in Table 9 below, and received power packets of modes '000', '001', '010', '011', and '100' can be represented as RP / 0, RP / 1, RP / 2, RP / 3, and RP / 4, respectively.

[0562] [Table 9]

[0563] Protocol for the initial power calibration

[0564] The wireless power transmitting device and / or the wireless power receiving device may perform initial power correction at each operating point using multiple received power packets. Here, the multiple received power values ​​may include a first received power packet (RP / 1) and a second received power packet (RP / 2). Every time the operating point of the wireless power receiving device is changed, the wireless power transmitting device and / or the wireless power receiving device may derive a new correction curve using the new received power packets (RP / 1 and RP / 2).

[0565] Specifically, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a first operating point (op.point 1). After receiving the first received power packet (RP / 1) and the second received power packet (RP / 2), the wireless power transmitting device configures a first power correction curve at the first operating point (op.point 1) based on the received power packet. The first power correction curve becomes the first segment of the correction curve.

[0566] Thereafter, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a second operating point (op.point 2). After receiving the first received power packet (RP / 1) and the second received power packet (RP / 2), the wireless power transmitting device configures a second power correction curve at the second operating point (op.point 2) based on the received power packets. The second power correction curve becomes the second segment of the correction curve.

[0567] Thereafter, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a third operating point (op.point 3). After receiving the first received power packet (RP / 1) and the second received power packet (RP / 2), the wireless power transmitting device configures a third power correction curve at the third operating point (op.point 3) based on the received power packets. The third power correction curve becomes the third segment of the correction curve.

[0568] FIG. 28 shows an example in which power correction curves are configured at three operating points (op. points 1, 2, and 3), but by changing the operating points of the wireless power receiving device, three or more power correction curves may be configured, or three or less power correction curves may be configured.

[0569] Protocol to extend the initial power calibration curve

[0570] The wireless power transmitting device and / or the wireless power receiving device can use the third received power packet (RP / 3) to derive an extended initial correction curve at the operating point.

[0571] Each time the wireless power receiving device needs to expand the initial power correction curve at each operating point (op.point 1, 2, 3), it can send a series or a number of RP / 3s to the wireless power transmitting device, allowing the wireless power transmitting device to expand the power correction curve.

[0572] Specifically, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a first operating point (op.point 1), and the wireless power transmitting device configures a first power correction curve based on the first received power packet (RP / 1) and the second received power packet (RP / 2). After that, the wireless power receiving device transmits a third received power packet (RP / 3) to the wireless power transmitting device. The wireless power transmitting device configures the first power correction curve to be extended based on the received third received power packet (RP / 3). The wireless power transmitting device configures the first power correction curve by extending a power correction curve that connects the estimated received power values ​​of the first received power packet (RP / 1) and the second received power packet (RP / 2) and connects the estimated received power values ​​of the second received power packet (RP / 2) and the third received power packet (RP / 3) (see FIG. 17 ).

[0573] The wireless power receiving device can also transmit a third received power packet (RP / 3) to the wireless power transmitting device at the second operating point (op.point 2) and / or the third operating point (op.point 3), and the wireless power transmitting device can receive the third received power packet (RP / 3) at each operating point and extend the second power correction curve and / or the third power correction curve.

[0574] According to an embodiment, the wireless power transmitting device and / or the wireless power receiving device may derive an extended initial correction curve at each operating point by using the second received power packet (RP / 2) instead of the third received power packet (RP / 3). That is, whenever the initial power correction curve at each operating point (op.point 1, 2, 3) needs to be extended, the wireless power receiving device may transmit a series or a number of additional RP / 2 packets to the wireless power transmitting device, so that the wireless power transmitting device extends the power correction curve.

[0575] Depending on the embodiment, the second receive power packet (RP / 2) may be named an additional receive power packet, and the third receive power packet (RP / 3) may be named an extended receive power packet.

[0576] FIG. 29 shows a power transmission characteristic or correction curve according to another embodiment of the present invention.

[0577] 29, a first segment of the correction curve (first power correction curve) may be defined by RP / 1, RP / 2, and RP / 3. In one aspect, the wireless power transmitting device and / or the wireless power receiving device may use the dual points RP / 1 and RP / 2 to derive or calculate an initial correction curve of the first power correction curve. In another aspect, the wireless power transmitting device and / or the wireless power receiving device may use RP / 3 to derive or calculate an extended correction curve of the first power correction curve. Here, one or more RP / 3s may be used to extend the initial correction curve of the first power correction curve. Furthermore, the relationship RP / 1<=RP / 2<=RP / 3 may hold.

[0578] The second segment of the correction curve may be determined or defined by a plurality of modes of received power packets (RP) different from the received power packets (RP) used to determine the first segment. For example, the next segment of the correction curve may be defined by a fifth received power packet (RP / 5), a sixth received power packet (RP / 6), and a seventh received power packet (RP / 7). In one aspect, the wireless power transmitting device and / or the wireless power receiving device may use the double points RP / 5 and RP / 6 to derive or calculate an initial correction curve for the second segment (second power correction curve). In another aspect, the wireless power transmitting device and / or the wireless power receiving device may use the seventh received power packet (RP / 7) to derive or calculate an extended correction curve for the second power correction curve. Here, one or more seventh received power packets (RP / 7) may be used to extend the initial correction curve for the second power correction curve. Furthermore, the relationship RP / 5<=RP / 6<=RP / 7 may hold.

[0579] As shown in FIG. 29, the fifth received power packet (RP / 5), the sixth received power packet (RP / 6), and the seventh received power packet (RP / 7) can be used as received power packets (RP) for configuring segments (power correction curves) above the third segment (third power correction curve).

[0580] The format of the received power packet according to this embodiment is the same as the format shown in Fig. 17. However, the mode field can indicate 0 to 7 as shown in Table 10 below, and received power packets of modes '000', '001', '010', '011', '100', '101', '110', and '111' can be represented as RP / 0, RP / 1, RP / 2, RP / 3, RP / 4, RP / 5, RP / 6, and RP / 7, respectively.

[0581] [Table 10]

[0582] That is, when the wireless power receiving device changes its operating point, it can use the first receive power packet set (RP / 1, RP / 2, RP / 3) or the second receive power packet set (RP / 5, RP / 6, RP / 7). That is, when the wireless power receiving device changes its operating point (op.point 1, 2, 3), the wireless power transmitting device can receive the first receive power packet set (RP / 1, RP / 2, RP / 3) or the second receive power packet set (RP / 5, RP / 6, RP / 7) from the wireless power receiving device. An example of a time when the wireless power receiving device changes its operating point can include the start of a power transmission phase. Another example of a time when the wireless power receiving device changes its operating point can include a time when the operating point is stepped up after renegotiating a power transmission contract (e.g., after successful authentication). Another example of a time when the wireless power receiving device changes its operating point can include a time when the operating point is stepped down during a power transmission phase.

[0583] Protocol for the initial power calibration

[0584] The wireless power transmitting device and / or the wireless power receiving device may perform initial power correction at each operating point using multiple received power packets. Here, the multiple received power values ​​may include a first received power packet (RP / 1) and a second received power packet (RP / 2). Every time the operating point of the wireless power receiving device is changed, the wireless power transmitting device and / or the wireless power receiving device may derive a new correction curve using new received power packets (RP / 5 and RP / 6).

[0585] Specifically, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a first operating point (op.point 1). After receiving the first received power packet (RP / 1) and the second received power packet (RP / 2), the wireless power transmitting device configures a first power correction curve at the first operating point (op.point 1) based on the received power packet. The first power correction curve becomes the first segment of the correction curve.

[0586] Thereafter, the wireless power receiving device transmits a fifth received power packet (RP / 5) and a sixth received power packet (RP / 6) at the second operating point (op.point 2). After receiving the fifth received power packet (RP / 5) and the sixth received power packet (RP / 6), the wireless power transmitting device configures a second power correction curve at the second operating point (op.point 2) based on the received fifth received power packet (RP / 5) and the sixth received power packet (RP / 6). The second power correction curve becomes the second segment of the correction curve.

[0587] Thereafter, the wireless power receiving device again transmits a fifth received power packet (RP / 5) and a sixth received power packet (RP / 6) at the third operating point (op.point 3). After receiving the fifth received power packet (RP / 5) and the sixth received power packet (RP / 6), the wireless power transmitting device configures a third power correction curve at the third operating point (op.point 3) based on the received fifth received power packet (RP / 5) and the sixth received power packet (RP / 6). The third power correction curve becomes the third segment of the correction curve.

[0588] FIG. 29 shows an example in which power correction curves are configured at three operating points (op.points 1, 2, and 3), but by changing the operating points of the wireless power receiving device, more than three power correction curves or less than three power correction curves can also be configured.

[0589] Protocol to extend the initial power calibration curve

[0590] The wireless power transmitting device and / or the wireless power receiving device can derive an expanded initial correction curve at each operating point using the third received power packet (RP / 3) or the seventh received power packet (RP / 7). Each time the wireless power receiving device needs to expand the initial power correction curve at each operating point (op.point 1, 2, 3), it can transmit a series or a number of the third received power packets (RP / 3) or the seventh received power packets (RP / 7) to the wireless power transmitting device, causing the wireless power transmitting device to expand the power correction curve.

[0591] Specifically, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a first operating point (op.point 1), and the wireless power transmitting device configures a first power correction curve based on the first received power packet (RP / 1) and the second received power packet (RP / 2). After that, the wireless power receiving device transmits a third received power packet (RP / 3) to the wireless power transmitting device. The wireless power transmitting device configures the first power correction curve to be extended based on the received third received power packet (RP / 3). The wireless power transmitting device configures the first power correction curve by extending a power correction curve that connects the estimated received power values ​​of the first received power packet (RP / 1) and the second received power packet (RP / 2) and connects the estimated received power values ​​of the second received power packet (RP / 2) and the third received power packet (RP / 3) (see FIG. 17 ).

[0592] The wireless power receiving device can transmit a seventh received power packet (RP / 7) at the second operating point (op.point 2) and / or the third operating point (op.point 3) to the wireless power transmitting device, and the wireless power transmitting device can receive the seventh received power packet (RP / 7) at each operating point to extend the second power correction curve and / or the third power correction curve.

[0593] Depending on the embodiment, the first receive power packet (RP / 1) and the fifth receive power packet (RP / 5) may be named first receive power packets, the second receive power packet (RP / 2) and the sixth receive power packet (RP / 6) may be named additional receive power packets, and the third receive power packet (RP / 2) and the seventh receive power packet (RP / 7) may be named extended receive power packets.

[0594] FIG. 30 shows a power transmission characteristic or correction curve according to another embodiment of the present invention.

[0595] Referring to FIG. 30 , a first segment of the correction curve (first power correction curve) may be defined by RP / 1, RP / 2, and RP / 3. In one aspect, the wireless power transmitting device and / or the wireless power receiving device may use the dual points RP / 1 and RP / 2 to derive or calculate an initial correction curve of the first power correction curve. In another aspect, the wireless power transmitting device and / or the wireless power receiving device may use RP / 3 to derive or calculate an extended correction curve of the first power correction curve. Here, one or more RP / 3s may be used to extend the initial correction curve of the first power correction curve. Also, the relationship RP / 1<=RP / 2<=RP / 3 may hold.

[0596] The next segment of the correction curve can be determined or defined by RP / 3. In one aspect, the wireless power transmitting device and / or the wireless power receiving device can use two RP / 3 double points to derive or calculate an initial correction curve. In another aspect, the wireless power transmitting device and / or the wireless power receiving device can use additional RP / 3 points to derive or calculate an extended correction curve.

[0597] The format of the received power packet according to this embodiment is the same as the format shown in Fig. 17. The mode field is the same as that in Table 9.

[0598] After the wireless power transmitting device receives the first received power packet (RP / 1), the second received power packet (RP / 2), and / or the third received power packet (RP / 3) from the wireless power receiving device and configures the first power correction curve or the extended first power correction curve, the wireless power receiving device can transmit the third received power packet (RP / 3) when changing its own operating point. That is, the wireless power transmitting device can receive the third received power packet (RP / 3) from the wireless power receiving device when the wireless power receiving device changes its own operating point (op.point 1, 2, 3).

[0599] An example of a time when the wireless power receiving device changes its operating point may include a time when the power transmission phase begins. Another example of a time when the wireless power receiving device changes its operating point may include a time when the operating point is stepped up after a power transmission contract is renegotiated (e.g., after successful authentication). Another example of a time when the wireless power receiving device changes its operating point may include a time when the operating point is stepped down during a power transmission phase.

[0600] Protocol for the initial power calibration

[0601] The wireless power transmitting device and / or the wireless power receiving device may perform initial power correction at each operating point using multiple received power packets. Here, the multiple received power values ​​may include a first received power packet (RP / 1) and a second received power packet (RP / 2). Every time the operating point of the wireless power receiving device is changed, the wireless power transmitting device and / or the wireless power receiving device may derive a new correction curve using the new received power packets (RP / 1 and RP / 2).

[0602] Specifically, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a first operating point (op.point 1). After receiving the first received power packet (RP / 1) and the second received power packet (RP / 2), the wireless power transmitting device configures a first power correction curve at the first operating point (op.point 1) based on the received power packet. The first power correction curve becomes the first segment of the correction curve.

[0603] Thereafter, the wireless power receiving apparatus sequentially transmits two third received power packets (RP / 3) at the second operating point (op.point 2). After receiving the two third received power packets (RP / 3), the wireless power transmitting apparatus configures a second power correction curve at the second operating point (op.point 2) based on the received two third received power packets (RP / 3). The second power correction curve becomes the second segment of the correction curve.

[0604] Thereafter, the wireless power receiving apparatus sequentially transmits two third received power packets (RP / 3) at a third operating point (op.point 3). After receiving the two third received power packets (RP / 3), the wireless power transmitting apparatus configures a third power correction curve at the third operating point (op.point 3) based on the received two third received power packets. The third power correction curve becomes the third segment of the correction curve.

[0605] FIG. 30 shows an example in which power correction curves are configured at three operating points (op.points 1, 2, and 3), but by changing the operating points of the wireless power receiving device, more than three power correction curves or less than three power correction curves can also be configured.

[0606] Protocol to extend the initial power calibration curve

[0607] The wireless power transmitting device and / or the wireless power receiving device can derive an extended initial correction curve at each operating point using the third received power packet (RP / 3).

[0608] Each time the wireless power receiving device needs to expand the initial power correction curve at each operating point (op.point 1, 2, 3), it can send a series or a number of RP / 3s to the wireless power transmitting device, allowing the wireless power transmitting device to expand the power correction curve.

[0609] Specifically, the wireless power receiving device transmits a first received power packet (RP / 1) and a second received power packet (RP / 2) at a first operating point (op.point 1), and the wireless power transmitting device configures a first power correction curve based on the first received power packet (RP / 1) and the second received power packet (RP / 2). After that, the wireless power receiving device transmits a third received power packet (RP / 3) to the wireless power transmitting device. The wireless power transmitting device configures the first power correction curve to be extended based on the received third received power packet (RP / 3). The wireless power transmitting device configures the first power correction curve by extending a power correction curve that connects the estimated received power values ​​of the first received power packet (RP / 1) and the second received power packet (RP / 2) and connects the estimated received power values ​​of the second received power packet (RP / 2) and the third received power packet (RP / 3) (see FIG. 17 ).

[0610] The wireless power receiving device can also transmit a third received power packet (RP / 3) to the wireless power transmitting device at the second operating point (op.point 2) and / or the third operating point (op.point 3), and the wireless power transmitting device can receive the third received power packet (RP / 3) at each operating point and extend the second power correction curve and / or the third power correction curve.

[0611] Depending on the embodiment, the second receive power packet (RP / 2) may be named an additional receive power packet, and the third receive power packet (RP / 3) may be named an extended receive power packet.

[0612] Hereinafter, a method for constructing a power correction curve according to another embodiment will be described.

[0613] FIG. 31 is a graph showing an initial power correction curve.

[0614] 31, when the wireless power receiving device configures an initial calibration curve, the wireless power receiving device can transmit at least a first received power packet (RP / 1) and a second received power packet (RP / 2) to the wireless power transmitting device. That is, when the wireless power receiving device configures an initial calibration curve, the wireless power transmitting device can receive at least RP / 1 and RP / 2 from the wireless power receiving device.

[0615] An example of the time when the wireless power receiving device configures the initial correction curve may include the start of the power transmission phase.

[0616] The x-axis and y-axis represent the measured transmission power value (t(est)) and the measured reception power value (r(est)), respectively, and the actual transmission power value is t and the actual reception power value is r. In this case, the following Equation 7 holds.

[0617] [Number 7] Pt(est)+δPt=Pt=Pr=Pr(est)-δPr

[0618] where ΔPt is the error between the actual transmit power value and the measured transmit power value, and ΔPr is the error between the actual receive power value and the measured receive power value. This is the case when no foreign object is detected using pre-power FOD.

[0619] Based on Equation 7, the corrected power value P(cal) can be calculated by Equation 8 below.

[0620] [Number 8] P(cal)=δPt+δPr=Pr(est)-Pt(est)

[0621] Therefore, by substituting RP / 1 and RP / 2 into Equation 8, the corrected power values ​​can be expressed as Equation 9 below.

[0622] [Number 9] P1(cal)=RP / 1-Pt1(est) P2(cal)=RP / 2-Pt2(est)

[0623] FIG. 32 is a graph showing an expanded power correction curve.

[0624] Referring to FIG. 32, after the initial correction curve is configured based on Equations 7 to 9, the wireless power transmitter and receiver can extend the initial correction curve based on a changed event (e.g., a change in the operating point of the wireless power receiver). For example, when a specific event occurs for the wireless power receiver, the wireless power receiver can transmit a third received power packet (RP / 3) to the wireless power transmitter. In this case, the wireless power transmitter can configure an extended correction curve by extending the initial correction curve using RP / 3. In FIG. 32, it can be seen that the slope of the correction curve changes before and after P2(cal). That is, the curve before P2(cal) is the initial correction curve, and the curve after P2(cal) is the extended correction curve.

[0625] If Equation 9 is directly applied to RP / 3, an additionally corrected power value can be derived as shown in Equation 10.

[0626] [Number 10] P3(cal)=RP / 3-Pt3(est)

[0627] Meanwhile, RP / 3 can be adopted as a new calibration point when it is located above the existing (or initial) calibration curve section (or range), thereby improving the detectability of foreign objects.

[0628] As an example, if RP / 3 exceeds the range of the existing correction curve, the existing correction curve may be expanded or modified.

[0629] As another example, if RP / 3 is lower than the range of the existing correction curve, the existing correction curve can be maintained according to more detailed conditions, or foreign object detection before power transmission can be performed.

[0630] For example, the wireless power transmission device can maintain an existing correction curve or perform foreign object detection before power transmission based on the result of comparing Pfo derived by the following Equation 11 with a threshold value (TH).

[0631] [Number 11] Pfo = Pt(est) + Pcal - Pr(est)

[0632] If Pfo is less than the threshold, it is assumed that no foreign object is present, and the wireless power transmitting device and / or receiving device can maintain the existing correction curve.

[0633] On the other hand, if Pfo is equal to or greater than the threshold, it is estimated that there is a high possibility that a foreign object is present, and the wireless power transmission apparatus can perform foreign object detection before transmitting power to confirm the presence of a foreign object. The specific operation for this is shown in FIG.

[0634] FIG. 33 illustrates a method for performing foreign object detection when Pfo is equal to or greater than a threshold.

[0635] Referring to FIG. 33, the method includes a step S2600 in which the wireless power receiving device transmits a third received power packet (RP / 3), a step S2610 in which the wireless power transmitting device, upon receiving the third received power packet (RP / 3), determines that Pfo is greater than or equal to a threshold and transmits an ATN pattern, a step S2615 in which the wireless power receiving device transmits a CE packet to the wireless power transmitting device, a step S2620 in which the wireless power receiving device transmits a DSR (poll) packet to the wireless power transmitting device, a step S2630 in which the wireless power transmitting device, upon receiving the DSR (poll) packet, transmits an end power transfer (EPT(PTx)) packet to the wireless power receiving device to request the wireless power receiving device to transmit an EPT packet in response to the DSR (poll) packet, and a step S2635 in which the wireless power receiving device, upon receiving the EPT(PTx) packet, transmits an EPT packet (EPT / rst or EPT / re-ping) to the wireless power transmitting device.

[0636] When a wireless power transmitting device receives an EPT packet (EPT / rst or EPT / re-ping) from a wireless power receiving device, the wireless power transmitting device performs foreign object detection before transmitting power. If it is determined that there is no foreign object as a result of the foreign object detection, the wireless power transmitting device performs a re-ping, and power recalibration can be performed during the power transmission stage.

[0637] The power transmission interrupt (EPT(PTx)) packet of the wireless power transmitting device may have the same format as the power transmission interrupt (EPT) packet of the wireless power receiving device, and the power transmission interrupt code (End Power Transfer code) may use the following values.

[0638] 0x00-EPT / nul-use if none of the other codes is appropriate.

[0639] 0x01 - Reserved

[0640] 0x02-EPT / if-PTx internal fault;use if an internal logic error has been encountered.

[0641] 0x03-EPT / ot-PTx over temperature;use if(e.g.)the battery temperature exceeds a limit.

[0642] 0x04-EPT / ov-PTx over voltage;use if a voltage exceeds a limit.

[0643] 0x05-EPT / oc-PTx over current;use if the current exceeds a limit.

[0644] 0x06-Reserved.

[0645] 0x08-Reserved.

[0646] 0x0A-Reserved.

[0647] 0x0B-EPT / rst-PTx restart;use to restart the power transfer.

[0648] NOTE PTx engages in FOD after stopping the power transfer and before restarting it.For details about this procedure.

[0649] 0x0C-EPT / rep-PTxre-ping;use to restart the power transfer after a specified delay(the re-ping delay).

[0650] NOTE.PTx should use this End Power Transfer Code only if it has verified that the PRx complies with version 1.3 or higher of the Qi Specification.

[0651] EPT / rfid-RFID / NFC card;use if an RFID / NFC card has been detected by PTx.

[0652] Hereinafter, a method for constructing a power correction curve according to another embodiment will be described.

[0653] FIG. 34 is a graph illustrating a method for modeling a correction curve according to an example.

[0654] 34, the wireless power transmitting device configures an initial correction curve (first power correction curve) using a first received power packet (RP / 1) and a second received power packet (RP / 2) received from the wireless power receiving device, and configures an updated correction curve (second power correction curve) by receiving a plurality of third received power packets (RP / 3) transmitted by the wireless power receiving device while changing the operating point from the first operating point (op.point 1) to the second operating point (op.point 2). The second received power packet (RP / 2) may be named an additional received power packet, and the third received power packet (RP / 3) may be named an extended received power packet.

[0655] FIG. 35 is a graph showing a method for modeling a correction curve according to another example.

[0656] 35, the wireless power transmitting device configures an initial correction curve (first power correction curve) using a first received power packet (RP / 1) and a second received power packet (RP / 2) received from the wireless power receiving device, and configures an updated correction curve (second power correction curve) by receiving the first received power packet (RP / 1) and the second received power packet (RP / 2) retransmitted by the wireless power receiving device while changing the operating point from the first operating point (op.point 1) to the second operating point (op.point 2). The second received power packet (RP / 2) can be called an additional received power packet.

[0657] FIG. 36 is a diagram illustrating a method for constructing an initial correction curve according to an embodiment.

[0658] 36, in order to configure an initial calibration curve, the wireless power receiving device may transmit a first received power packet (RP / 1) and a second received power packet (RP / 2) to the wireless power transmitting device. That is, the wireless power transmitting device may receive the first received power packet (RP / 1) and the second received power packet (RP / 2) from the wireless power receiving device and configure the initial calibration curve based on the received power packet. An example of a time when the wireless power receiving device configures the initial calibration curve may include a start time of the power transmission phase.

[0659] If P(cal) (e.g., P1(cal) and / or P2(cal)) calculated based on Equation 7, Equation 8, and Equation 9 described in the embodiment of FIG. 31 is a negative number, the value can be set to 0. This is because a negative P(cal) can increase the number of false foreign object detection events. Therefore, the initial correction curve is configured to exceed the uncorrected curve, thereby further improving the ability to detect foreign objects compared to the uncorrected curve.

[0660] According to FIG. 36, the initial correction curve constructed based on the first received power packet (RP / 1) and the second received power packet (RP / 2) can be interpreted as a linear function with a gradient a.

[0661] The slope a can be expressed by the following equation 12.

[0662]

number

[0663] Meanwhile, when the wireless power transmission device identifies the risk of a foreign object using the correction curve, the wireless power transmission device needs to confirm the presence of the foreign object using pre-power FOD (pre-power FOD).

[0664] The wireless power transmission apparatus can calculate Pfo based on Equation 11 described in the embodiment of Fig. 31 and estimate whether a foreign object is present based on Pfo. As described in the embodiment of Fig. 31, the wireless power transmission apparatus compares Pfo with a threshold value (TH), and if Pfo is less than the threshold value, estimates that a foreign object is not present, whereas if Pfo is equal to or greater than the threshold value, estimates that a foreign object is likely to be present, and can proceed with a protocol for performing foreign object detection, for example, as shown in Fig. 33.

[0665] Meanwhile, a calibration time-out for the initial calibration can be defined. If the wireless power transmitting apparatus cannot transmit an ACK response to the second received power packet (RP / 2) received from the wireless power receiving apparatus within the calibration time-out, the power signal can be removed. The calibration time-out can be defined within a range of, for example, 13.5±1.5 seconds.

[0666] After the initial correction curve is constructed, the correction curve can be updated in certain situations.

[0667] As an example, the wireless power receiving device can update the y-intercept of the correction curve by sending only a single correction point to the wireless power transmitting device using RP / 3.

[0668] FIG. 37 shows a correction curve in which the y-intercept of the initial correction curve is updated.

[0669] 37, when a specific event (e.g., an operating point change) occurs in the wireless power receiving device, the wireless power receiving device can transmit a third received power packet (RP / 3) to the wireless power transmitting device. The wireless power transmitting device can configure a new correction curve by updating the y-intercept while maintaining the slope (a1) of the initial correction curve using the received single third received power packet (RP / 3). The wireless power receiving device can continuously transmit the third received power packet (RP / 3) until it receives an ACK from the wireless power transmitting device, and the wireless power transmitting device can configure a new correction curve using the third received power packet (RP / 3) that has transmitted an ACK among the third received power packets (RP / 3) transmitted by the wireless power receiving device. The third received power packet (RP / 3) can be called an extended received power packet.

[0670] By applying Equation 9 to RP / 3, the additionally corrected power value (P3(cal)) can be derived as shown in Equation 10.

[0671] As mentioned above, to prevent false foreign object detection events, if P(cal) is negative, its value can be set to 0. Therefore, the correction curve updated by the third received power packet (RP / 3) is configured to exceed the uncorrected curve, thereby further improving foreign object detection capability compared to the uncorrected case.

[0672] The wireless power transmission apparatus can calculate Pfo based on Equation 11 described in the embodiment of Fig. 31 and estimate whether a foreign object is present based on Pfo. As described in the embodiment of Fig. 31, the wireless power transmission apparatus compares Pfo with a threshold value (TH), and if Pfo is less than the threshold value, estimates that a foreign object is not present, whereas if Pfo is equal to or greater than the threshold value, estimates that a foreign object is likely to be present, and can proceed with a protocol for performing foreign object detection, for example, as shown in Fig. 33.

[0673] Although an example of constructing an updated correction curve using a single third received power packet (RP / 3) has been described, an updated correction curve can be constructed using the first received power packet (RP / 1) instead of the third received power packet (RP / 3). That is, when a specific event (e.g., an operating point change) occurs, the wireless power receiving apparatus transmits an additional first received power packet (RP / 1) to the wireless power transmitting apparatus, and the wireless power transmitting apparatus can construct a new correction curve by updating the y-intercept while maintaining the slope (a1) of the initial correction curve using the received first received power packet (RP / 1).

[0674] Although an example of constructing an updated correction curve using a single third received power packet (RP / 3) has been described, an updated correction curve can be constructed using a second received power packet (RP / 2) instead of the third received power packet (RP / 3). That is, when a specific event (e.g., an operating point change) occurs, the wireless power receiving apparatus transmits an additional second received power packet (RP / 2) to the wireless power transmitting apparatus, and the wireless power transmitting apparatus can construct a new correction curve by updating the y-intercept while maintaining the slope (a1) of the initial correction curve using the received second received power packet (RP / 2). The second received power packet (RP / 2) can be referred to as an additional received power packet.

[0675] As another example, the wireless power receiving device can update the slope and y-intercept of the correction curve by sending multiple consecutive correction points to the wireless power transmitting device using RP / 3.

[0676] FIG. 38 shows the correction curve with the slope and y-intercept of the initial correction curve updated.

[0677] 38, when a specific event (e.g., an operating point change) occurs in the wireless power receiving device, the wireless power receiving device can transmit multiple consecutive third received power packets (RP / 3) to the wireless power transmitting device. In this case, the wireless power transmitting device can configure a new correction curve by updating the slope and y-intercept of the initial correction curve using the multiple third received power packets (RP / 3).

[0678] As shown in FIG. 38, a new correction curve can be constructed having a new slope (a2) and y-intercept passing through (Pt3(1), RP3(1)) and (Pt3(2), RP3(2)).

[0679] By applying Equation 9 to RP / 3, the additionally corrected power value (P3(cal)) can be derived as shown in Equation 10.

[0680] As mentioned above, to prevent false foreign object detection events, if P(cal) is negative, its value can be set to 0. Therefore, the correction curve updated by the third received power packet (RP / 3) is configured to exceed the uncorrected curve, thereby further improving foreign object detection capability compared to the uncorrected case.

[0681] The wireless power transmission apparatus can calculate Pfo based on Equation 11 described in the embodiment of Fig. 31 and estimate whether a foreign object is present based on Pfo. As described in the embodiment of Fig. 31, the wireless power transmission apparatus compares Pfo with a threshold value (TH), and if Pfo is less than the threshold value, estimates that a foreign object is not present, whereas if Pfo is equal to or greater than the threshold value, estimates that a foreign object is likely to be present, and can proceed with a protocol for performing foreign object detection, for example, as shown in Fig. 33.

[0682] Meanwhile, a calibration time-out for updating the calibration curve can be defined.

[0683] The calibration time-out for updating the calibration curve may be defined as the time required for the wireless power transmitting apparatus to transmit an ACK response to the next received third received power packet (RP / 3) after receiving the first third received power packet (RP / 3) transmitted by the wireless power receiving apparatus for updating the calibration curve. For example, the calibration time-out for updating the calibration curve may be defined within a range of 7±1.5 seconds.

[0684] Although an example of constructing an updated correction curve using a plurality of third received power packets (RP / 3) has been described, an updated correction curve can be constructed using new first received power packets (RP / 1) and second received power packets (RP / 2) instead of the plurality of third received power packets (RP / 3). That is, when a specific event (e.g., an operating point change) occurs, the wireless power receiving apparatus transmits additional first received power packets (RP / 1) and second received power packets (RP / 2) to the wireless power transmitting apparatus, and the wireless power transmitting apparatus can construct a new correction curve using the received new first received power packets (RP / 1) and second received power packets (RP / 2). The second received power packet (RP / 2) can be referred to as an additional received power packet.

[0685] In this case, the calibration time-out for updating the calibration curve can be defined as the time required from when the wireless power transmitting device receives the first received power packet (RP / 1) transmitted by the wireless power receiving device for updating the calibration curve until when it transmits an ACK response to the next received second received power packet (RP / 2).

[0686] The wireless power transmitting apparatus in the embodiments of Figures 28 to 38 corresponds to the wireless power transmitting apparatus, wireless power transmitter, or power transmitting unit disclosed in Figures 1 to 15. Therefore, the operation of the wireless power transmitting apparatus in the present embodiment is implemented by one or a combination of two or more of the components of the wireless power transmitting apparatus in Figures 1 to 15. For example, an operation of receiving a received power packet from the wireless power receiving apparatus, an operation of configuring a correction curve, etc. may be performed by the communication / control unit 120.

[0687] The wireless power receiving apparatus in the embodiments of Figures 28 to 38 corresponds to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in Figures 1 to 15. Therefore, the operation of the wireless power receiving apparatus in the present embodiment is implemented by one or a combination of two or more of the components of the wireless power receiving apparatus in Figures 1 to 15. For example, an operation of transmitting a received power packet to the wireless power transmitting apparatus may be performed by the communication / control unit 220.

[0688] Since not all components or steps are required for the wireless power transmission method and apparatus, or the receiving apparatus and method according to the above-described embodiments of the present invention, the wireless power transmission apparatus and method, or the receiving apparatus and method may be implemented by including some or all of the above-described components or steps. Furthermore, the above-described embodiments of the wireless power transmission apparatus and method, or the receiving apparatus and method may be implemented in combination with each other. Furthermore, the above-described components or steps do not necessarily have to be implemented in the order described, and a later-described step may be implemented before an earlier-described step.

[0689] The above description merely illustrates the technical concept of the present invention, and various modifications and variations may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the above-described embodiments of the present invention may be embodied separately or in combination with each other.

[0690] Therefore, the embodiments disclosed in the present invention are for illustrative purposes only and are not intended to limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention should not be limited by such embodiments. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

Claims

1. A wireless power receiving device, a power pickup configured to receive wireless power from a wireless power transmitter; a controller configured to control the wireless power; The wireless power receiving device includes: transmitting a control error packet including a control error value to the wireless power transmitting device; transmitting a first received power packet associated with a power correction to the wireless power transmitting device in a first operating mode; receiving an ACK based on the control error value from the wireless power transmitting device in response to the first received power packet; After receiving the ACK, transmitting a second received power packet related to a power correction to the wireless power transmitting device in the first operating mode; Sending an end power transfer (EPT) packet to the wireless power transmitting device based on changing an operation mode from the first operation mode to a second operation mode; transmitting a third received power packet associated with a power correction to the wireless power transmitting device in the second operating mode; The wireless power receiving device transmits a fourth received power packet related to a power correction to the wireless power transmitting device in the second operating mode.

2. A method for receiving wireless power from a wireless power transmitting device, comprising: The method is performed by a wireless power receiving device, transmitting a control error packet including a control error value to the wireless power transmitting device; transmitting a first received power packet associated with a power correction to the wireless power transmitting device in a first operating mode; receiving an ACK based on the control error value from the wireless power transmitting device in response to the first received power packet; after receiving the ACK, transmitting a second received power packet related to a power correction to the wireless power transmitting device in the first operating mode; transmitting an end power transfer (EPT) packet to the wireless power transmitting device based on changing an operation mode from the first operation mode to a second operation mode; transmitting a third received power packet associated with a power correction to the wireless power transmitting device in the second operating mode; transmitting a fourth received power packet associated with a power correction to the wireless power transmitting device in the second mode of operation.

3. A wireless power transmission device, a converter configured to transmit wireless power to a wireless power receiving device; a controller configured to control the wireless power; The wireless power transmission device includes: receiving a control error packet including a control error value from the wireless power receiving device; receiving a first received power packet associated with a power correction from the wireless power receiving device in a first operating mode; transmitting an ACK based on the control error value to the wireless power receiving device in response to the first received power packet; receiving a second received power packet from the wireless power receiving device in the first operating mode, the second received power packet being associated with a power correction after transmitting the ACK; receiving an end power transfer (EPT) packet from the wireless power receiving device based on changing an operation mode from the first operation mode to a second operation mode; receiving a third received power packet from the wireless power receiving device in the second operating mode, the third received power packet being associated with a power correction; The wireless power transmitting device receives a fourth received power packet related to a power correction from the wireless power receiving device in the second operating mode.

4. A method for transmitting wireless power to a wireless power receiving device, comprising: The method is performed by a wireless power transmission device, receiving a control error packet including a control error value from the wireless power receiving device; receiving a first received power packet associated with a power correction from the wireless power receiving device in a first mode of operation; transmitting an ACK based on the control error value to the wireless power receiving device in response to the first received power packet; receiving, after transmitting the ACK, a second received power packet associated with a power correction in the first operating mode from the wireless power receiving device; receiving an end power transfer (EPT) packet from the wireless power receiving device based on changing an operation mode from the first operation mode to a second operation mode; receiving a third received power packet from the wireless power receiving device in the second operating mode, the third received power packet being associated with a power correction; receiving a fourth received power packet from the wireless power receiving device in the second mode of operation, the fourth received power packet being associated with a power correction.

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