Wireless power transmission device, wireless power transmission method, wireless power receiving device, and wireless power receiving method

Abstract

A wireless power transmitting device according to an embodiment of the present specification receives information on received power values ​​for two or more correction points for power correction from a wireless power receiving device, configures a power correction curve for foreign object detection based on the information on the received power values, and transmits the data packet requesting initiation of a power correction protocol for updating the power correction curve.

Description

[Technical Field]

[0001] The present specification relates to a wireless power transmitting apparatus, a wireless power receiving apparatus that receives wireless power from the wireless power transmitting apparatus, and a wireless power transmitting method and a wireless power receiving method that use the wireless power receiving apparatus and the wireless power transmitting apparatus. [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 a wireless device, such as a smartphone or tablet, to be charged simply by placing the device on a wireless charging pad, thereby providing greater mobility, convenience, and safety than existing wired charging environments that use wired charging connectors. In addition to wireless charging of 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. Patent document 1 also describes that a wireless power transmitting device transmits a specific bit pattern response, that the bit pattern response is 8 bits and is sometimes called ATN (attention), that the wireless power transmitting device requests the wireless power receiving device to transmit a power-related packet, that the power-related packet may be an EPT packet or a re-ping start packet, that if the power-related packet is an EPT packet, the EPT packet may include EPT / rst (0x0B), that the wireless power transmitting device induces a re-ping or an EPT (power transfer interruption) by transmitting a power-related request packet to the wireless power receiving device in response to a DSR (poll) packet, and that when the wireless power transmitting device receives the power-related packet, it resets the wireless power receiving device according to the value indicated by the power-related packet and performs Q measurement and FOD again. [Prior art document] [Patent documents] [Patent Document 1] International Publication No. 2019 / 208960 Summary of the Invention [Problem to be solved by the invention]

[0005] The technical problem of this specification is to provide a wireless power transmission device, a wireless power transmission method, a wireless power receiving device, a wireless power receiving method, and a wireless charging system that perform power correction for detecting a foreign object during power transmission.

[0006] The technical problems of this specification are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0007] A wireless power transmitting device according to one embodiment of the present specification for solving the above problem includes: a power conversion circuit that transmits wireless power to a wireless power receiving device and transmits the wireless power to the wireless power receiving device; and a communication / control circuit that communicates with the wireless power receiving device to control the wireless power, receives information on received power values ​​for two or more correction points for power correction from the wireless power receiving device, and configures a power correction curve for foreign object detection based on the information on the received power values. The communication / control circuit receives a received power packet (RP) from the wireless power receiving device, including information on the received power received by the wireless power receiving device, transmits a response pattern (ATN) to the wireless power receiving device requesting permission to communicate in response to the received power packet, receives a data stream response packet (DSR) from the wireless power receiving device requesting transmission of a data packet, and transmits the data packet requesting initiation of a power correction protocol for updating the power correction curve in response to the DSR.

[0008] A wireless power transmission method according to one embodiment of the present specification for solving the above problem is a wireless power transmission method by a wireless power transmission device that transmits wireless power to a wireless power receiving device, the method comprising: receiving, from the wireless power receiving device, information on received power values ​​for two or more correction points for power correction; constructing a power correction curve for foreign object detection based on the information on the received power values; receiving, from the wireless power receiving device, a received power packet (RP) including information on the received power received by the wireless power receiving device; transmitting, to the wireless power receiving device, a response pattern (ATN) requesting communication authority in response to the received power packet; receiving, from the wireless power receiving device, a data stream response packet (DSR) requesting transmission of a data packet; and transmitting, in response to the DSR, the data packet requesting initiation of a power correction protocol for updating the power correction curve.

[0009] A wireless power receiving device according to one embodiment of the present specification for solving the above problem includes: a power pickup circuit that receives wireless power from a wireless power transmitting device; and a communication / control circuit that communicates with the wireless power transmitting device and controls the wireless power. The communication / control circuit transmits a received power packet (RP) to the wireless power transmitting device, including information on the received power received by the wireless power receiving device; receives an answer pattern (ATN) from the wireless power transmitting device requesting permission to communicate as a response to the received power packet; transmits a data stream response packet (DSR) to the wireless power transmitting device, including a request to transmit a data packet as a response to the ATN; receives from the wireless power transmitting device the data packet requesting initiation of a power correction protocol for updating a power correction curve for foreign object detection as a response to the DSR; and transmits an additional received power packet (RP / 2) including information on a received power value for an additional correction point or transmits a first received power packet (RP / 1) including information on a received power value for a first correction point based on the information contained in the data packet.

[0010] A wireless power receiving method according to one embodiment of the present specification for solving the above problem is a wireless power receiving method by a wireless power receiving device that receives wireless power from a wireless power transmitting device, the method comprising: transmitting a received power packet (RP) to the wireless power transmitting device, the received power packet including information on the received power received by the wireless power receiving device; receiving an answer pattern (ATN) from the wireless power transmitting device requesting permission to communicate as a response to the received power packet; transmitting a data stream response packet (DSR) to the wireless power transmitting device requesting transmission of a data packet as a response to the ATN; receiving from the wireless power transmitting device the data packet requesting initiation of a power correction protocol for updating a power correction curve for foreign object detection as a response to the DSR; and transmitting an additional received power packet (RP / 2) including information on a received power value for an additional correction point or transmitting a first received power packet (RP / 1) including information on a received power value for a first correction point based on the information included in the data packet.

[0011] Other specific details of the present specification are contained in the detailed description and drawings. [Effects of the Invention]

[0012] During power transmission, the power correction curve for foreign object detection can be updated according to the needs of the wireless power transmission device.

[0013] The effects of the present specification are not limited to the above-mentioned examples, and a wider variety of effects are included within the present specification. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a block diagram of a wireless power system according to one embodiment. [Figure 2] FIG. 10 is a block diagram of a wireless power system according to another embodiment. [Figure 3a] 1 illustrates various embodiments of electronic devices into which a wireless power transmission system may be incorporated. [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] FIG. 1 is a block diagram illustrating a wireless power transmission system using BLE communication according to an example. [Figure 4c] FIG. 10 is a block diagram showing 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 is a flow chart illustrating a dual point power correction method. [Figure 10] 10 is a graph showing an example of a power correction curve according to a double-point power correction method. [Figure 11] 10 illustrates a format of a message field of a received power packet according to an example. [Figure 12] 10 is a diagram illustrating a format of a message field of a received power packet according to another example. [Figure 13] 10 is a flow diagram illustrating a power correction protocol for constructing an extended power correction curve according to one embodiment. [Figure 14] 10 illustrates a format of a message field of a power correction request packet according to an embodiment. [Figure 15] 10 is a diagram illustrating a format of a message field of a power correction request packet according to another embodiment. [Figure 16] 10 is a diagram illustrating an example of an extended power correction curve configured through an extended power correction protocol. [Figure 17]10 is a flow diagram illustrating a power correction protocol for construction of a power recalibration curve according to one embodiment. [Figure 18] 10 is a diagram showing an example of a new power correction curve constructed through a power re-correction protocol. DETAILED DESCRIPTION OF THE INVENTION

[0015] 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."

[0016] 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."

[0017] 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."

[0018] 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."

[0019] 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 "PDCCH" 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."

[0020] 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, transmitting power via magnetic coupling, transmitting power via radio frequency (RF), transmitting power via microwave, and transmitting power via ultrasound.

[0021] FIG. 1 is a block diagram of a wireless power system 10 according to one embodiment.

[0022] Referring to FIG. 1, a wireless power system 10 includes a wireless power transmitting device 100 and a wireless power receiving device 200.

[0023] The wireless power transmitting apparatus 100 receives power from an external power source S to generate a magnetic field. The wireless power receiving apparatus 200 receives power wirelessly by generating a current using the generated magnetic field.

[0024] 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 interchangeably. Examples of out-band communication include NFC, Bluetooth (registered trademark), and Bluetooth Low Energy (BLE).

[0025] 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.

[0026] 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.

[0027] FIG. 2 is a block diagram of a wireless power system 10 according to another embodiment.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] FIG. 3a shows various examples of electronic devices in which the wireless power transmission system can be implemented.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] Standards for wireless power transmission include the wireless power consortium (WPC), the air fuel alliance (AFA), and the power matters alliance (PMA).

[0037] 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.

[0038] 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.

[0039] 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.

[0040] The PC0 standard relates to wireless power transmitters and receivers that provide a guaranteed power of 5W. The PC0 standard includes EPP, which provides a guaranteed power of 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.

[0041] 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.

[0042] The PC2 standard relates to wireless power transmitters and receivers that provide guaranteed power between 200W and 2kW, and its applications include kitchen appliances.

[0043] 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.

[0044] 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:

[0045] 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.

[0046] 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.

[0047] 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.

[0048] The profiles can be broadly divided into three categories: i) mobile and computer, ii) power tools, and iii) kitchen.

[0049] Alternatively, the profiles can be broadly divided into four categories: i) mobile, ii) power tools, iii) kitchen, and iv) wearable.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] FIG. 3b shows an example of WPC NDEF in a wireless power transmission system.

[0055] 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.

[0056] 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.

[0057] Maintaining compatibility within the same profile is a requirement, while maintaining compatibility between different profiles is an option.

[0058] 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.

[0059] 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.

[0060] 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, although it has been defined to maintain compatibility between the same profiles until now, technology may develop in the future 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.

[0061] 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.

[0062] [Table 1]

[0063] [Table 2]

[0064] The maximum output power capability of a Class n PTU is greater than or equal to the PTX_IN_MAX value for that class, as shown in Table 1. A PRU cannot draw more power than specified for that category.

[0065] FIG. 4a is a block diagram of a wireless power transmission system according to another embodiment.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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 (registered trademark), NFC, etc.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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).

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] Examples of short-range communication modules include Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, and NFC communication modules.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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. 4b.

[0092] FIG. 4b is a block diagram illustrating a wireless power transmission system using BLE communication according to an example.

[0093] 4b, 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] FIG. 4c is a block diagram illustrating another example of a wireless power transmission system using BLE communication.

[0098] Referring to FIG. 4c, the communication / control circuits 120, 220 may each include only an in-band communication module 121, 221, and the BLE communication module 122, 222 may be provided separately from the communication / control circuits 120, 220.

[0099] 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.

[0100] FIG. 5 is a state transition diagram for explaining a wireless power transmission procedure.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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).

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] In this embodiment, the identification and configuration stage 530 may also be referred to as the configuration stage.

[0116] 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.

[0117] 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.

[0118] FIG. 6 illustrates a power control method according to one embodiment.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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 .

[0126] The coil assembly 760 includes at least one primary coil that generates a magnetic field, also referred to as a coil cell.

[0127] The impedance matching circuit 770 can provide impedance matching between the inverter and the primary coil. 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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 .

[0137] 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.

[0138] 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.

[0139] 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.

[0140] The communications circuitry 890 may perform load modulation to communicate requests and other information to the power transmitter.

[0141] To that end, the power receiver 830 may also switch resistors or capacitors to change the reflected impedance.

[0142] 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.

[0143] 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.

[0144] The following describes foreign object detection in the power transmission stage system and power correction based on the foreign object detection result.

[0145] 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.

[0146] The power lost by the foreign object is calculated based on the power transmitted by the wireless power transmitter (P transmitted ) the power actually received by the wireless power receiving device (P received) can be defined as the value obtained by subtracting the transmitted power (P transmitted ) is known, the actual power received by the wireless power receiving device (P received ), the power loss can be calculated. To this end, the wireless power receiving device periodically transmits a received power data packet (RP) to the wireless power transmitting device to inform the wireless power transmitting device of the power received by the wireless power receiving device.

[0147] 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.

[0148] 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.

[0149] FIG. 9 is a flow chart for explaining a dual-point power correction method, FIG. 10 is a graph showing an example of a power correction curve according to the dual-point power correction method, FIG. 11 is a diagram showing the format of a message field of a received power packet according to one example, and FIG. 12 is a diagram showing the format of a message field of a received power packet according to another example.

[0150] Referring to FIG. 9, at the start of the power transmission phase, a power correction protocol is performed, and the wireless power receiving device 1002 transmits a first received power packet (RP / 1) and a second received power packet (RP / 2), allowing the wireless power transmitting device 1001 to construct a dual-point power correction curve.

[0151] More specifically, the wireless power receiving device 1002 transmits a control error packet (CE) to the wireless power transmitting device (S1101), and transmits a first received power packet (RP / 1) including information on a first calibration data point to the wireless power transmitting device (S1102).

[0152] The control error packet includes a control error value. The control error value includes information regarding the deviation between the target operating point and the actual operating point of the wireless power receiving apparatus 1002. For example, if the control error value is a positive number, it means that the actual operating point is lower than the target operating point, and the wireless power transmitting apparatus 1001 receiving this control error value can increase the power of the wireless power to be transmitted. Conversely, if the control error value is a negative number, it means that the actual operating point is higher than the target operating point, and the wireless power transmitting apparatus 1001 receiving this control error value can decrease the power of the wireless power to be transmitted.

[0153] 11 or 12, the first received power packet (RP / 1) includes a mode field and an estimated received power value (ERP / 1) field. The wireless power transmitting apparatus 1001 can confirm that the received power packet (RP) received from the wireless power receiving apparatus 1002 is the first received power packet (RP / 1) including information on the first correction data point through the value (e.g., 1) of the mode field of the first received power packet (RP / 1), and can confirm the first correction data point through the value of the estimated received power value field of the first received power packet (RP / 1).

[0154] The first correction data point is the starting point of the power correction curve and may be a power level corresponding to approximately 10% of the Reference Power level of the Power Transfer Contract established during the negotiation phase.

[0155] The wireless power transmitting apparatus 1001 determines whether the wireless power receiving apparatus 1002 has reached the desired target power point based on the control error value included in the control error packet, and responds with an ACK or NAK to the first received power packet (RP / 1) (S1103). More specifically, the wireless power transmitting apparatus 1001 determines whether the power level has stabilized at the first correction data point based on the control error value. For example, if the control error value is less than 3, the wireless power transmitting apparatus 1001 may determine that the power level has stabilized and the wireless power receiving apparatus 1002 has reached the desired target power point, and may respond with an ACK to the first received power packet (RP / 1). If the control error value is less than 3, the wireless power transmitting apparatus 1001 may determine that the power level has not stabilized and the wireless power receiving apparatus 1002 has not reached the desired target power point, and may respond with a NAK to the first received power packet (RP / 1).

[0156] The wireless power receiving apparatus 1002 continues to transmit the first received power packet (RP / 1) (S1102) until it receives an ACK from the wireless power transmitting apparatus 1001. The wireless power receiving apparatus 1002 also repeatedly transmits a control error packet to the wireless power transmitting apparatus 1001 so that the power level can be stabilized at the first correction data point (S1101).

[0157] After the power level is stabilized at the first calibration data point and an ACK for the first received power packet (RP / 1) is received from the wireless power transmitting device 1001 (S1103), a control error packet is transmitted to the wireless power transmitting device (S1104), and the wireless power receiving device 1002 transmits a second received power packet (RP / 2) including information for the second calibration data point to the wireless power transmitting device 1001 (S1105).

[0158] The second received power packet (RP / 2) also includes a Mode field and an Estimated Received Power Value field (see FIG. 11 or 12). The wireless power transmitting apparatus 1001 can confirm that the received power packet (RP) received from the wireless power receiving apparatus 1002 is the second received power packet (RP / 2) including information on the second correction data point through the value (e.g., 0) of the Mode field of the second received power packet (RP / 2), and can confirm the second correction data point through the value of the Estimated Received Power Value field of the second received power packet (RP / 2).

[0159] The second correction data point is a point for constructing a power correction curve, and may be a power level close to the reference power level of the power transfer contract established during the negotiation stage.

[0160] The wireless power transmitting apparatus 1001 determines whether the wireless power receiving apparatus 1002 has reached the desired target power point based on the control error value included in the control error packet, and responds with an ACK or NAK to the second received power packet (RP / 2) (S1106). More specifically, the wireless power transmitting apparatus 1001 determines whether the power level has stabilized at the second correction data point based on the control error value. For example, if the control error value is less than 3, the wireless power transmitting apparatus 1001 determines that the power level has stabilized and the wireless power receiving apparatus 1002 has reached the desired target power point, and may respond with an ACK to the second received power packet (RP / 2) (S1106). If the control error value is less than 3, the wireless power transmitting apparatus 1001 determines that the power level has not stabilized and the wireless power receiving apparatus 1002 has not reached the desired target power point, and may respond with a NAK to the second received power packet (RP / 2).

[0161] The wireless power receiving apparatus 1002 continues to transmit the second received power packet (RP / 2) until it receives an ACK from the wireless power transmitting apparatus 1001 (S1105). The wireless power receiving apparatus 1002 also repeatedly transmits a control error packet to the wireless power transmitting apparatus 1001 so that the power level can be stabilized at the second correction data point (S1104).

[0162] After the power level is stabilized at the second calibration data point and an ACK for the second received power packet (RP / 2) is received from the wireless power transmitter 1001 (S1106), the wireless power receiver 1002 and the wireless power transmitter 1001 enter a normal power transmission mode. The wireless power transmitter 1001 generates a power calibration curve (see FIG. 10) based on the first received power packet (RP / 1) and the second received power packet (RP / 2) for which the ACK has been sent, and can use the curve to perform foreign object detection based on the loss of transmission power (S1107).

[0163] More specifically, the wireless power transmitting apparatus 1001 receives a received power packet (e.g., RP / 0 where the value of the mode field is 0) from the wireless power receiving apparatus 1002 while transmitting power, checks the received power value received by the wireless power receiving apparatus 1002 through the received power packet, and if the difference between the corrected power value calculated by applying the transmitted power value to the power correction curve and the received power value checked through the received power packet is greater than or equal to a critical value, it can be assumed that power loss has occurred due to a foreign object.

[0164] Referring to FIG. 10, the power correction curve constructed by the above-described double-point power correction method will be described.

[0165] The wireless power transmitting apparatus 1001 generates a power calibration curve (A) based on the first received power packet (RP / 1) and the second received power packet (RP / 2) for which ACK has been sent.

[0166] If the predicted value of the transmission power is Pt(est), the predicted value of the reception power is Pr(est), the actual transmission power is Pt, and the actual reception power is Pr, and if it is confirmed that there is no foreign object between the wireless power transmission device and the wireless power reception device through foreign object detection (pre-power FOD) before power transmission, the following [Equation 1] is established.

[0167]

number

[0168] Here, ΔPt is a predicted error value of the transmission power, which may include an independent power loss value of the wireless power transmitting device, etc. ΔPr is a predicted error value of the reception power, which may include an independent power loss value of the wireless power receiving device, etc.

[0169] Based on [Equation 1], the corrected power value P(cal) can be calculated by the following [Equation 2].

[0170]

number

[0171] Therefore, by substituting RP / 1 (first correction data point) and RP / 2 (second correction data point) into Equation 2, the corrected power values ​​can be expressed as the following Equation 3.

[0172]

number

[0173] That is, when the absence of foreign matter is confirmed by pre-power FOD, the relationships shown in Equations 1 to 3 are established, and the correction curve based on Equations 1 to 3 can be illustrated as graph A in FIG. 10.

[0174] However, the power transmission characteristics may 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 required to match the changed power transmission characteristics.

[0175] Therefore, a power correction protocol must be performed during the power transmission phase to update the initial power correction curve configured at the start of the power transmission phase.

[0176] Furthermore, if the wireless power transmission apparatus 1001 suspects the presence of a foreign object during power transmission, the wireless power transmission apparatus 1001 can update the power correction curve for foreign object detection at a desired time point.

[0177] A method for updating the power correction curve by the wireless power transmission apparatus 1001 will be described below.

[0178] (1) Extended power correction curve configuration

[0179] FIG. 13 is a flow diagram illustrating a power correction protocol for construction of an extended power correction curve according to one embodiment.

[0180] 13 may be performed in the power transfer phase. Before entering the power transfer phase, the wireless power transmitting apparatus 1001 and the wireless power receiving apparatus 1002 may go through a Ping Phase, a Configuration Phase, and a Negotiation Phase, and then enter the power transfer phase.

[0181] After entering the power transmission stage, the wireless power transmitting device 1001 provides wireless power to the wireless power receiving device 1002 according to the power transmission contract established in the negotiation stage.

[0182] 13, after entering the power transmission step, the wireless power receiving apparatus 1002 transmits a received power packet (RP / 0) to the wireless power transmitting apparatus 1001 as information on the wireless power received from the wireless power transmitting apparatus 1001 (S1201). The received power packet (RP / 0) transmitted in step S1201 may be a received power packet in which the value of the mode field is set to 0, and the RP / 0 includes information on the estimated received power value of the wireless power received by the wireless power receiving apparatus 1002 (see FIG. 11 or 12).

[0183] If the wireless power transmitting apparatus 1001 determines that foreign object detection is necessary, the wireless power transmitting apparatus 1001 can transmit an ATN response pattern to the wireless power receiving apparatus 1002 as a response to the RP / 0 packet transmitted by the wireless power receiving apparatus 1002 (S1202). The ATN response pattern is an 8-bit response pattern ('11001100'b) and can be used to request communication permission from the wireless power receiving apparatus 1002 when, for example, the wireless power transmitting apparatus 1001 has a data packet to transmit.

[0184] Upon receiving the ATN, the wireless power receiving apparatus 1002 transmits a data stream response packet (DSR / poll) to the wireless power transmitting apparatus 1001 to request the wireless power transmitting apparatus 1001 to transmit a data packet (S1203). The DSR / poll is a type of data stream response packet (DSR) transmitted by the wireless power receiving apparatus 1002, and has an 8-bit message field, to which a value of 0x33 can be set.

[0185] The wireless power transmitting apparatus 1001, which has received a DSR / poll from the wireless power receiving apparatus 1002, can transmit a data packet (hereinafter referred to as a power correction request packet) requesting the start of a power correction protocol to the wireless power receiving apparatus 1002 (S1204).

[0186] FIG. 14 illustrates a format of a message field of a power correction request packet according to an embodiment.

[0187] Referring to FIG. 14, a power correction request packet according to an embodiment may include a byte (B0) including a request field and a byte (B1) including a mode field.

[0188] The request field may include header information of a message (data packet) that the wireless power transmitting apparatus 1001 requests to be transmitted to the wireless power receiving apparatus 1002. Since the wireless power transmitting apparatus 1001 must receive a received power packet (RP) from the wireless power receiving apparatus 1002 to correct the power, the request field may include 0x31, which is the header value of the RP.

[0189] The mode field may include a mode value of a received power packet (RP) that the wireless power transmitting apparatus 1001 requests to be transmitted to the wireless power receiving apparatus 1002. For example, if the wireless power transmitting apparatus 1001 is to receive a received power packet (RP / 1) of mode 1 including information on a first correction data point, the value of the mode field of the power correction request packet may be set to 1, and if the wireless power transmitting apparatus 1001 is to receive a received power packet (RP / 2) of mode 2 including information on a second correction data point, the value of the mode field of the power correction request packet may be set to 2.

[0190] Step S1204 assumes that the wireless power transmitting device 1001 desires to start a power correction protocol for configuring an extended power correction curve, so the wireless power transmitting device 1001 can transmit a power correction request packet to the wireless power receiving device 1002, with the mode field value set to 2.

[0191] FIG. 15 is a diagram illustrating a format of a message field of a power correction request packet according to another embodiment.

[0192] Referring to FIG. 15, a power correction request packet according to another embodiment may include a request field.

[0193] The request field may include information about the type of power correction protocol desired by the wireless power transmitting apparatus 1001.

[0194] Power correction protocols subsequent to the initial power correction protocol (see FIG. 9) may include an extended power correction protocol (see FIG. 13) that extends the power correction curve configured in the initial power correction protocol and updates the power correction curve, and a power re-correction protocol (see FIG. 17) that deletes the power correction curve configured in the initial power correction protocol, configures a new power correction curve, and updates the power correction curve.

[0195] 15 may be set differently depending on whether the power correction protocol desired by the wireless power transmitting apparatus 1001 is the extended power correction protocol or the power re-correction protocol. For example, in step S1204, if the wireless power transmitting apparatus 1001 desires to start the power re-correction protocol (or desires to receive a received power packet (RP / 1) having a mode value of 1), it may transmit a power correction request packet with the value of the request field set to 1 ('01'b) to the wireless power receiving apparatus 1002. If the wireless power transmitting apparatus 1001 desires to start the extended power correction protocol (or desires to receive a received power packet (RP / 2) having a mode value of 2), it may transmit a power correction request packet with the value of the request field set to 2 ('10'b) to the wireless power receiving apparatus 1002. Alternatively, in step S1204, if the wireless power transmitting apparatus 1001 desires to start a power recalibration protocol, it may transmit a power correction request packet with a request field value set to 2 ('10'b) to the wireless power receiving apparatus 1002, and if the wireless power transmitting apparatus 1001 desires to start an extended power correction protocol, it may transmit a power correction request packet with a request field value set to 1 ('01'b) to the wireless power receiving apparatus 1002. The request field may be configured with 2 bits, and the value of the request field may be set to any one of 0 to 4 values ​​that can be represented by 2 bits depending on whether the power correction protocol desired by the wireless power transmitting apparatus 1001 is the extended power correction protocol or the power recalibration protocol.

[0196] Step S1204 assumes that the wireless power transmitting device 1001 desires to start a power correction protocol for configuring an extended power correction curve, so the wireless power transmitting device 1001 can transmit a power correction request packet to the wireless power receiving device 1002, with the value of the request field set to a value indicating the extended power correction protocol.

[0197] 15, a power correction request packet according to another embodiment can be used as a slot request packet for foreign object detection (FOD). To this end, the power correction request packet includes a slot number field (# of slots) and a slot length field in addition to a request field.

[0198] The slot for foreign object detection refers to a time during which the wireless power transmitting apparatus 1001 temporarily suspends power transmission to detect a foreign object.

[0199] The slot number field may include information on the number of slots or the minimum number of slots required for foreign object detection by the wireless power transmitter 1001. The slot length field may include information on the length (time) of a slot required for foreign object detection or the minimum value of the slot length.

[0200] Referring to FIG. 15, the slot number field can be composed of 2 bits and the slot length field can be composed of 3 bits, but this is just one example and the number of bits constituting each field can be changed.

[0201] The value of the slot length field can be set in a manner such that, for example, '000'b means that no slot is required, '001'b means 100 μs, '010'b means 110 μs, and '011'b means 120 μs. This is just one example, and the correlation between the value of the slot length field and the length of the actually required slot can be changed in various ways.

[0202] On the other hand, when the power correction request packet is used as a slot request packet for foreign object detection, the request field may have a value different from when the wireless power transmitting apparatus 1001 desires the extended power correction protocol or the power re-correction protocol. For example, when the power correction request packet is used as a slot request packet for foreign object detection, the request field may be set to 0.

[0203] Referring again to FIG. 13, upon receiving the power correction request packet, the wireless power receiving apparatus 1002 transmits RP / 1 or RP / 2 based on the power correction request packet.

[0204] 14, it can transmit RP / 1 or RP / 2 to the wireless power transmitting apparatus 1001 based on the value of the mode field. For example, if the value of the mode field is 1, it can transmit RP / 1 with a mode value of 1, and if the value of the mode field is 2, it can transmit an additional received power packet (RP / 2) with a mode value of 2.

[0205] However, since the power correction protocol described with reference to FIG. 13 is a power correction protocol for constructing an extended power correction curve, assuming that the wireless power transmitting apparatus 1001 has transmitted a power correction request packet in which the value of the mode field is set to 2 in step S1204, the wireless power receiving apparatus 1002 transmits an additional received power packet (RP / 2) including estimated received power value information, which is a third calibration data point, to the wireless power transmitting apparatus 1001 (S1205).

[0206] 15, the wireless power receiving apparatus 1002 can transmit RP / 1 or RP / 2 to the wireless power transmitting apparatus 1001 based on the request field. That is, if the value of the request field indicates the power re-correction protocol, the wireless power receiving apparatus 1002 can transmit RP / 1, and if the value of the request field indicates the extended power correction protocol, the wireless power receiving apparatus 1002 can transmit RP / 1.

[0207] However, since the power correction protocol described with reference to FIG. 13 is a power correction protocol for configuring an extended power correction curve, assuming that the wireless power transmitting apparatus 1001 has transmitted a power correction request packet having a value in the request field indicating the extended power correction protocol in step S1204, the wireless power receiving apparatus 1002 transmits an additional received power packet (RP / 2) to the wireless power transmitting apparatus 1001 (S1205).

[0208] Although not shown, the wireless power receiving apparatus 1002 may transmit a control error packet before transmitting the additional received power packet (RP / 2) in step S1205, and the wireless power transmitting apparatus 1001 determines whether the wireless power receiving apparatus 1002 has reached the desired target operating point based on a control error value included in the control error packet and responds with an ACK or NAK to the additional received power packet (RP / 2) (S1206). For example, if the control error value is less than 3, the wireless power transmitting apparatus 1001 may determine that the power level has stabilized and the wireless power receiving apparatus 1002 has reached the desired target operating point and responds with an ACK to the additional received power packet (RP / 2) (S1206). If the control error value is less than 3, the wireless power transmitting apparatus 1001 may determine that the power level has not stabilized and the wireless power receiving apparatus 1002 has not reached the desired target operating point and responds with a NAK to the additional received power packet (RP / 2). The wireless power receiving apparatus 1002 can continue to transmit the additional received power packet (RP / 2) and the control error packet until it receives an ACK from the wireless power transmitting apparatus 1001.

[0209] After the ACK for the additional received power packet (RP / 2) is transmitted / received (S1206), the wireless power receiving apparatus 1002 and the wireless power transmitting apparatus 1001 can enter the normal power transmission mode.

[0210] The wireless power transmission device 1001 extends the existing power correction curve based on the additional received power packet (RP / 2) for which ACK has been sent (see FIG. 16), and can perform foreign object detection based on loss of transmission power using the extended power correction curve (S1207).

[0211] After performing foreign object detection, the wireless power transmitting apparatus 1001 can transmit the foreign object detection result to the wireless power receiving apparatus 1002 (S1208). The foreign object detection result can be expressed as an ACK or a NAK. That is, if the wireless power transmitting apparatus 1001 determines that no foreign object is present as a result of performing foreign object detection, it can transmit an ACK to the wireless power receiving apparatus 1002, and if it determines that a foreign object is present, it can transmit a NAK to the wireless power receiving apparatus 1002.

[0212] If it is determined that no foreign object is present, the wireless power transmitting apparatus 1001 and the wireless power receiving apparatus 1002 can continue to maintain the power transmission stage.

[0213] If it is determined that a foreign object is present, the wireless power receiving device 1002 may either maintain the existing operation point and receive power according to the existing power transmission contract, or switch to a low power mode in which the received power is 5W or less, or send an EPT (End Power transfer data packet) to the wireless power transmitting device 1001 to interrupt the power transmission phase, reset the wireless power transmitting device 1001, and initialize the protocol for wireless power transmission so that foreign object detection (pre-power transfer FOD) is performed before transmitting power.

[0214] FIG. 16 is a diagram illustrating an example of an extended power correction curve configured through an extended power correction protocol.

[0215] Referring to FIG. 16, the wireless power transmission apparatus 1001 constructs a power correction curve based on the correction data points included in the first received power packet (RP / 1), the second received power packet (RP / 2), and the additional received power packet (RP / 2) that have transmitted ACK.

[0216] When the wireless power transmission device 1001 constructs a power correction curve based on three correction data points, it can construct a first power correction curve (B1) that connects the first correction data point (Pt1, RP / 1) and the second correction data point (Pt2, RP / 2), and a second power correction curve (B2) that connects the second correction data point (Pt2, RP / 2) and the third correction data point (Pt3, RP / 3).

[0217] In the power correction curve, the first power correction curve (B1) constructed based on the first received power packet (RP / 1) and the second received power packet (RP / 2) may be an existing power correction curve constructed at the beginning of the power transmission stage.

[0218] The wireless power transmission device 1001 can acquire information on the third correction data point (Pt3, RP / 3) based on information acquired from the additional received power packet (RP / 2) that transmitted ACK using the extended power correction protocol while storing parameters for the existing power correction curve (B1), and can configure a second power correction curve (B2) that extends from the existing power correction curve (B1) to the third correction data point (Pt3, RP / 3).

[0219] The first power correction curve (B1) and the second power correction curve (B2) may be defined as linear functions having different slopes and y-intercepts, and the wireless power transmitting apparatus 1001 subsequently detects a foreign object based on a loss of transmission power using parameters of the power correction curves, including the received power value, the first power correction curve (B1), and the second power correction curve (B2), confirmed using a received power packet (e.g., RP / 0) received from the wireless power receiving apparatus 1002 (S1207).

[0220] The wireless power transmission device 1001 can extend the power correction curve to a desired point through the above-mentioned extended power correction protocol, thereby increasing the correction range and correcting a wider range of power values. As a result, the reliability of the correction increases, and the reliability of foreign object detection based on power loss also increases.

[0221] (2) Configuration of the power recalibration curve

[0222] FIG. 17 is a flow diagram illustrating a power correction protocol for constructing a power recalibration curve (hereinafter referred to as power recalibration protocol) according to one embodiment.

[0223] Each step shown in FIG. 17 can be performed in the power transmission step.

[0224] Steps S1201, S1202 and S1203 have been described with reference to FIG. 13, so further description thereof will be omitted.

[0225] Upon receiving the DSR / poll from the wireless power receiving apparatus 1002, the wireless power transmitting apparatus 1001 can transmit a power correction request packet to the wireless power receiving apparatus 1002 (S1304).

[0226] 17 is a power re-correction protocol, so when transmitting a power correction request packet having the message field of FIG. 14 in step S1304, the wireless power transmission apparatus 1001 transmits a power correction request packet in which the value of the mode field is set to 1. When transmitting a power correction request packet having the message field of FIG. 15 in step S1304, the wireless power transmission apparatus 1001 transmits a power correction request packet in which the value of the request field indicates the power re-correction protocol.

[0227] Upon receiving the power correction request packet, the wireless power receiving apparatus 1002 transmits a first received power packet (RP / 1) including estimated received power value information, which is a first calibration data point, based on the information included in the power correction request packet (S1305). The first received power packet (RP / 1) is a received power packet with a mode value of 1.

[0228] Although not shown, the wireless power receiving apparatus 1002 may transmit a control error packet before transmitting the first received power packet (RP / 1) in step S1305, and the wireless power transmitting apparatus 1001 determines whether the wireless power receiving apparatus 1002 has reached a desired target operating point based on the control error value included in the control error packet and responds to the first received power packet (RP / 1) with an ACK or NAK (S1306). The wireless power receiving apparatus 1002 may continue to transmit the first received power packet (RP / 1) and the control error packet until it receives an ACK from the wireless power transmitting apparatus 1001.

[0229] After transmitting / receiving an ACK for the first received power packet (RP / 1) (S1306), the wireless power receiving apparatus 1002 transmits a second received power packet (RP / 2) including estimated received power value information, which is a second calibration data point, based on information included in the power correction request packet (S1307). The second received power packet (RP / 2) is a received power packet with a mode value of 2.

[0230] Although not shown, the wireless power receiving apparatus 1002 may transmit a control error packet before transmitting the second received power packet (RP / 2) in step S1307, and the wireless power transmitting apparatus 1001 determines whether the wireless power receiving apparatus 1002 has reached a desired target power point based on the control error value included in the control error packet and responds with an ACK or NAK to the second received power packet (RP / 2) (S1308). The wireless power receiving apparatus 1002 may continue to transmit the second received power packet (RP / 2) and the control error packet until it receives an ACK from the wireless power transmitting apparatus 1001.

[0231] After the ACK for the second received power packet (RP / 2) is transmitted / received (S1308), the wireless power receiving apparatus 1002 and the wireless power transmitting apparatus 1001 can enter the normal power transmission mode.

[0232] The wireless power transmission device 1001 updates the existing power correction curve (C1) to a new power correction curve (C2) based on the first received power packet (RP / 1) and the second received power packet (RP / 2) for which ACK has been sent (see FIG. 18), and can perform foreign object detection based on loss of transmission power using the new power correction curve (C2) (S1309).

[0233] After performing foreign object detection, the wireless power transmitting apparatus 1001 can transmit the foreign object detection result to the wireless power receiving apparatus 1002 (S1310). The foreign object detection result can be expressed as an ACK or a NAK. That is, if the wireless power transmitting apparatus 1001 determines that no foreign object is present as a result of performing foreign object detection, it can transmit an ACK to the wireless power receiving apparatus 1002, and if it determines that a foreign object is present, it can transmit a NAK to the wireless power receiving apparatus 1002.

[0234] If it is determined that there is no foreign object, the wireless power transmitting apparatus 1001 and the wireless power receiving apparatus 1002 can continue to maintain the power transmission stage.

[0235] If it is determined that a foreign object is present, the wireless power receiving device 1002 can either maintain the existing operation point and receive power according to the existing power transmission contract, switch to a low power mode where the received power is 5W or less, or send an EPT (End Power transfer data packet) to the wireless power transmitting device 1001 to interrupt the power transmission phase, reset the wireless power transmitting device 1001, initialize the protocol for wireless power transmission, and perform foreign object detection (pre-power transfer FOD) before transmitting power.

[0236] FIG. 18 is a diagram showing an example of a new power correction curve constructed through the power re-correction protocol.

[0237] Referring to FIG. 18, the wireless power transmission device 1001 discards the existing power correction curve (C1), constructs a new power correction curve (C2) based on the correction data points included in the first received power packet (RP / 1) and the second received power packet (RP / 2) that have sent ACK, and performs foreign object detection based on loss of transmission power using the parameters of the new power correction curve (C2) (S1309).

[0238] If necessary, for example, when the wireless power receiving device changes the operating point (e.g., target rectified voltage) during power transmission, the wireless power transmitting device 1001 can perform power re-correction without resetting the wireless power transmitting device. Therefore, it is possible to prevent an increase in charging time for the wireless power receiving device due to resetting the wireless power transmitting device, and since it is possible to update the power correction curve according to the operating point change, the reliability of foreign object detection is also increased.

[0239] The wireless power transmission apparatus in the above-described embodiments according to Figures 9 to 18 corresponds to the wireless power transmission apparatus, wireless power transmitter, or power transmission unit disclosed in Figures 1 to 8. 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 Figures 1 to 8. For example, the transmission of a power correction request packet by the wireless power transmission apparatus, the configuration, expansion, and / or reconstruction of a power correction curve, the execution of a foreign object detection method, the transmission of an ACK / NAK according to the foreign object detection result, and the transmission / reception of other data packets and response patterns may be performed by the communication / control circuit 120, 710, and / or 790.

[0240] 9 to 18 correspond to the wireless power receiving apparatus, wireless power receiver, or power receiving unit disclosed in FIGS. 1 to 8. Therefore, the operation of the wireless power receiving apparatus in the present embodiment is implemented by one or a combination of two or more components of the wireless power receiving apparatus in FIGS. 1 to 8. For example, reception of a power correction request packet by the wireless power receiving apparatus, transmission of a received power packet based on the power correction packet, reception of an ACK / NAK based on a foreign object detection result, reception / transmission of other data packets, etc. may be performed by the communication / control unit 220, 810, and / or 890.

[0241] Since not all components or steps are required for the wireless power transmission method and apparatus, or the receiving device and method according to the above-described embodiments of the present invention, the wireless power transmission device and method, or the receiving device 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 device and method, or the receiving device 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.

[0242] The above description merely illustrates the technical concept of the present invention, and various modifications and variations are possible 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 individually or in combination with each other.

[0243] 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. The scope of protection of the present invention should be interpreted by the appended claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of rights of the present invention.

Claims

1. In a wireless power transmission device, a power converter configured to transmit wireless power to a wireless power receiving device; a communicator and a controller configured to control the wireless power; The wireless power transmission device includes: receiving a first RP (received power) packet for a first correction data point from the wireless power receiving device in a power transmitting step, the first RP packet having a mode value of 1; receiving a second RP packet for a second correction data point from the wireless power receiving device during the power transmitting step, the second RP packet having a mode value of 2; constructing a correction curve for detecting a foreign object based on the first RP packet and the second RP packet in the power transmission step; receiving a specific RP packet having a mode value of 0 from the wireless power receiving device during the power transmitting step; transmitting a response pattern to the wireless power receiving device in response to the specific RP packet, the response pattern requesting permission to communicate; receiving a data stream response (DSR) packet from the wireless power receiving device during the power transmission step, the data stream response (DSR) packet instructing the wireless power transmitting device to transmit a data packet; and transmitting a specific data packet to the wireless power receiving device in the power transmission step based on receiving the DSR packet; the specific data packet of the wireless power transmission device includes information notifying that the wireless power transmission device requests recalibration; Based on the fact that the recalibration is performed after transmitting the specific data packet in the power transmission phase, the wireless power transmission device receives a new first RP packet having a mode value of 1 and a new second RP packet having a mode value of 2 in the changed operating mode, and configures a new correction curve based on the new first RP packet and the new second RP packet in the power transmission phase.

2. 1. A method for transmitting wireless power to a wireless power receiving device, comprising: Executed by a wireless power transmission device, receiving a first received power (RP) packet for a first correction data point from the wireless power receiving device in a power transmitting step, the first RP packet having a mode value of 1; receiving a second RP packet for a second correction data point from the wireless power receiving device during the power transmitting step, the second RP packet having a mode value of 2; constructing a correction curve for foreign object detection based on the first RP packet and the second RP packet in the power transmission step; receiving a specific RP packet having a mode value of 0 from the wireless power receiving device during the power transmitting step; transmitting a response pattern to the wireless power receiving device in response to the specific RP packet, requesting permission to communicate; receiving a data stream response (DSR) packet from the wireless power receiving device during the power transmission step, the DSR packet instructing the wireless power transmitting device to transmit a data packet; transmitting a specific data packet to the wireless power receiving device in the power transmitting step based on receiving the DSR packet; the specific data packet of the wireless power transmission device includes information notifying that the wireless power transmission device requests recalibration; A method in which, based on the fact that the recalibration is performed after transmitting the specific data packet in the power transmission phase, the wireless power transmission device receives a new first RP packet having a mode value of 1 and a new second RP packet having a mode value of 2 in the changed operating mode, and configures a new correction curve based on the new first RP packet and the new second RP packet in the power transmission phase.

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