Wireless power receiving apparatus, wireless power transmitting apparatus, and power calibration method using same

Abstract

The disclosure relates to a wireless power receiving device, a wireless power transmitting device, and a power calibration method using the same. A wireless power transmitting apparatus according to an embodiment of the present specification corresponds to a wireless power transmitting apparatus for performing wireless power transmission to a wireless power receiving apparatus. After the negotiation phase, the wireless power transmitting device: receives a first received power packet from the wireless power receiving device, the first received power packet comprising an estimated received power value indicating a first calibration data point; transmitting an ACK on the first received power packet; receiving a second received power packet from the wireless power receiving device, the second received power packet including an estimated received power value indicative of a second calibration data point; transmitting an ACK on the second received power packet; receiving a new second received power packet from the wireless power receiving device, the new second received power packet including an estimated received power value indicating a third calibration data point; transmitting an ACK with respect to the new second received power packet; and configuring a power calibration curve by using the first received power packet, the second received power packet, and the new second received power packet.

Description

[0001] This application is a divisional application of the patent application with application number 202080068207.6 (PCT / KR2020 / 013484) filed on March 29, 2022, with an international application date of October 5, 2020, and the invention name is "Wireless power receiving device, wireless power transmitting device and power calibration method using the same". Technical Field

[0002] The present disclosure relates to a wireless power transmission device, a wireless power reception device that receives wireless power from the wireless power transmission device, and a method for calibrating power. Background Art

[0003] Wireless power transmission (or transmission) technology corresponds to a technology that can wirelessly transmit (or transmit) power between a power source and an electronic device. For example, by allowing the battery of a wireless device such as a smartphone or tablet PC to be recharged simply by placing the wireless device on a wireless charging pad, wireless power transmission technology can provide greater mobility, convenience, and safety than traditional wired charging environments using wired charging connectors. In addition to wireless charging of wireless devices, wireless power transmission technology is attracting attention as an alternative to traditional wired power transmission environments in various fields such as electric vehicles, Bluetooth headsets, 3D glasses, various wearable devices, household (or home) appliances, furniture, underground facilities, buildings, medical equipment, robots, entertainment, etc.

[0004] Wireless power transmission (or transmission) methods are also referred to as contactless power transmission methods, contactless power transmission methods, or wireless charging methods. A wireless power transmission system may include a wireless power transmitter that supplies power using the wireless power transmission method and a wireless power receiver that receives the power supplied by the wireless power transmitter and supplies the received power to a receiver such as a battery cell.

[0005] Wireless power transmission technology includes various methods, for example, a method of transmitting power by using magnetic coupling, a method of transmitting power by using radio frequency (RF), a method of transmitting power by using microwaves, and a method of transmitting power by using ultrasound (or ultrasonic waves). The methods based on magnetic coupling are classified into a magnetic induction method and a magnetic resonance method. The magnetic induction method corresponds to a method of transmitting power by using a current induced to the coil of the receiver by a magnetic field generated from the coil battery cell of the transmitter according to the electromagnetic coupling between the transmitting coil and the receiving coil. The magnetic resonance method is similar to the magnetic induction method in terms of the use of a magnetic field. However, the difference between the magnetic resonance method and the magnetic induction method is that energy is transmitted due to the accumulation of the magnetic field (caused by the generated resonance) on both the transmitting end and the receiving end. Summary of the Invention

[0006] Technical issues

[0007] The technical purpose of the present disclosure is to provide a wireless power transmission device, a wireless power reception device, and a method for calibrating power using the devices, which are capable of more accurately detecting foreign matter between the wireless power transmission device and the wireless power reception device.

[0008] The technical objectives to be achieved by the present disclosure are not limited to the above-mentioned technical objectives, and based on the following description, other technical objectives not described above will be clearly understood by ordinary technicians in the field to which the present disclosure belongs.

[0009] Technical Solution

[0010] In order to solve the above problems, according to one embodiment of the present disclosure, the wireless power transmitting device is a wireless power transmitting device that transmits wireless power to a wireless power receiving device; and after the negotiation phase, receives a first receiving power packet including an estimated receiving power value for a first calibration data point from the wireless power receiving device, sends ACK in response to the first receiving power packet, receives a second receiving power packet including an estimated receiving power value for a second calibration data point from the wireless power receiving device, sends ACK in response to the second receiving power packet, receives a new second receiving power packet including an estimated receiving power value for a third calibration data point from the wireless power receiving device, sends ACK in response to the new second receiving power packet, and constructs a power calibration curve based on the first receiving power packet, the second receiving power packet and the new second receiving power packet.

[0011] In order to solve the above problems, according to one embodiment of the present disclosure, the wireless power receiving device is a wireless power receiving device that receives wireless power from a wireless power transmitting device; and after the negotiation phase, a first receiving power packet including an estimated receiving power value for a first calibration data point is sent to the wireless power transmitting device, an ACK in response to the first receiving power packet is received from the wireless power transmitting device, a second receiving power packet including an estimated receiving power value for a second calibration data point is sent to the wireless power transmitting device, an ACK in response to the second receiving power packet is received from the wireless power transmitting device, a new second receiving power packet including an estimated receiving power value for a third calibration data point is sent to the wireless power transmitting device, and an ACK in response to the new second receiving power packet is received from the wireless power transmitting device.

[0012] In order to solve the above problems, according to one embodiment of the present disclosure, a wireless power receiving device is a wireless power receiving device that receives wireless power from a wireless power transmitting device; and after the negotiation phase, a first receiving power packet including an estimated receiving power value for a first calibration data point is sent to the wireless power transmitting device, an ACK in response to the first receiving power packet is received from the wireless power transmitting device, a second receiving power packet including an estimated receiving power value for a second calibration data point is sent to the wireless power transmitting device, an ACK in response to the second receiving power packet is received from the wireless power transmitting device, and based on the change of the target operating point, a new second receiving power packet including an estimated receiving power value for a third calibration data point is sent to the wireless power transmitting device or a new first receiving power packet including an estimated receiving power value for a new first calibration data point and a new second receiving power packet including an estimated receiving power value indicating a new second calibration data point are sent to the wireless power transmitting device.

[0013] Other details of the disclosure are included in the detailed description and drawings.

[0014] Beneficial effects

[0015] According to the present disclosure, foreign matter between a wireless power transmission device and a wireless power reception device can be detected more accurately.

[0016] The effects according to the present disclosure are not limited to the above exemplary contents, and more various effects are included in the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a block diagram of a wireless power system (10) according to an exemplary embodiment of the present disclosure.

[0018] Figure 2 is a block diagram of a wireless power system (10) according to another exemplary embodiment of the present disclosure.

[0019] Figure 3a Exemplary embodiments of various electronic devices employing wireless power transfer systems are shown.

[0020] Figure 3b An example of WPC NDEF in a wireless power transmission system is shown.

[0021] Figure 4 is a block diagram of a wireless power transmission system according to another exemplary embodiment of the present disclosure.

[0022] Figure 5 It is a state transition diagram used to describe the wireless power transfer process.

[0023] Figure 6A power control method according to an exemplary embodiment of the present disclosure is shown.

[0024] Figure 7 is a block diagram of a wireless power transmitter according to another exemplary embodiment of the present disclosure.

[0025] Figure 8 is a block diagram of a wireless power receiver according to another exemplary embodiment of the present invention.

[0026] Figure 9 An operating state of a wireless power transmitter and a wireless power receiver in a sharing mode according to an exemplary embodiment of the present disclosure is shown.

[0027] Figure 10 is a state diagram illustrating a two-point power calibration method.

[0028] Figure 11 is a graph illustrating a power calibration curve according to a two-point power calibration method.

[0029] Figure 12 is a flow chart illustrating a multi-point power calibration method according to one embodiment.

[0030] Figure 13 FIGURE 1 illustrates the format of a received power packet according to one embodiment.

[0031] Figure 14 is a state diagram illustrating a multi-point power calibration method using multiple RP / 2 according to one embodiment.

[0032] Figure 15 is a graph illustrating a power calibration curve according to a multi-point power calibration method using multiple RP / 2s according to one embodiment.

[0033] Figure 16 is a graph illustrating a power calibration curve according to a multi-point power calibration method using a plurality of RP / 2 according to another embodiment.

[0034] Figure 17 is a state diagram illustrating a multi-point power calibration method using RP / 3 according to one embodiment.

[0035] Figure 18 is a graph illustrating a power calibration curve according to a multi-point power calibration method using RP / 3 according to one embodiment.

[0036] Figure 19 is a flow chart illustrating a power recalibration method according to one embodiment.

[0037] Figure 20 is a state diagram illustrating a power recalibration method according to one embodiment.

[0038] Figure 21 is a graph illustrating a power calibration curve according to a power recalibration method according to one embodiment.

[0039] Figure 22 is a flow chart illustrating a power calibration method according to one embodiment. DETAILED DESCRIPTION

[0040] In this specification, "A or B" may mean "only A," "only B," or "both A and B." In other words, "A or B" in this specification may be interpreted as "A and / or B." For example, in this specification, "A, B, or C" may mean "only A," "only B," "only C," or any combination of "A, B, and C."

[0041] As used in this specification, a slash mark ( / ) or a comma may mean "and / or." For example, "A / B" may mean "A and / or B." Thus, "A / B" may mean "only A," "only B," or "both A and B." For example, "A, B, C" may mean "A, B, or C."

[0042] In this specification, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in this specification, the expression “at least one of A or B” or “at least one of A and / or B” may be interpreted as being the same as “at least one of A and B”.

[0043] In addition, in this specification, “at least one of A, B, and C” may mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.” In addition, “at least one of A, B, or C” or “at least one of A, B, and / or C” may mean “at least one of A, B, and C.”

[0044] In addition, the brackets used in this specification may refer to "for example". Specifically, when indicated as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, the "control information" in this specification is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information". In addition, even when indicated as "control information (ie, PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0045] In this specification, technical features described independently in one drawing may be implemented independently or simultaneously. The term "wireless power" used hereinafter in this specification will be used to refer to any form of energy related to electric fields, magnetic fields and electromagnetic fields that is transmitted (or sent) from a wireless power transmitter to a wireless power receiver without using any physical electromagnetic conductors. Wireless power may also be referred to as a wireless power signal, and this may refer to an oscillating magnetic flux surrounded by a primary coil and a secondary coil. For example, power conversion for wirelessly charging devices within a system including mobile phones, cordless phones, iPods, MP3 players, headphones, etc. will be described in this specification. Generally, the basic principles of wireless power transmission technology include all of a method of transmitting power by using magnetic coupling, a method of transmitting power by using radio frequency (RF), a method of transmitting power by using microwaves, and a method of transmitting power by using ultrasound (or ultrasonic waves).

[0046] Figure 1 is a block diagram of a wireless power system (10) according to an exemplary embodiment of the present invention.

[0047] refer to Figure 1 , a wireless power system (10) includes a wireless power transmitter (100) and a wireless power receiver (200).

[0048] The wireless power transmitter (100) is supplied with power from an external power source (S) and generates a magnetic field. The wireless power receiver (200) generates current using the generated magnetic field, thereby being able to wirelessly receive power.

[0049] In addition, in the wireless power system (10), the wireless power transmitter (100) and the wireless power receiver (200) can transceive (send and / or receive) various information required for wireless power transmission. Herein, the communication between the wireless power transmitter (100) and the wireless power receiver (200) can be performed (or established) in accordance with either in-band communication using a magnetic field for wireless power transmission (or transmission) or out-of-band communication using a separate communication carrier. Out-of-band communication can also be referred to as out-of-band communication. Hereinafter, out-of-band communication will be mainly described. Examples of out-of-band communication may include NFC, Bluetooth, Bluetooth Low Energy (BLE), etc.

[0050] Here, the wireless power transmitter (100) can be provided as a fixed type or a mobile (or portable) type. Examples of the fixed transmitter type may include an embedded type embedded in an indoor ceiling or wall or embedded in furniture such as a table, an embedded type installed in an outdoor parking lot, a bus stop, a subway station, etc., or installed in a vehicle such as a car or a train. The mobile (or portable) type wireless power transmitter (100) may be implemented as part of another device, for example, a cover of a mobile device or a laptop computer having a portable size or weight.

[0051] In addition, the wireless power receiver (200) should be understood as a comprehensive concept including various home appliances and devices that are operated by being supplied with power wirelessly rather than various electronic devices equipped with batteries and power cables. Typical examples of the wireless power receiver (200) may include portable terminals, cellular phones, smart phones, personal digital assistants (PDAs), portable media players (PDPs), Wibro terminals, tablet PCs, tablet phones, laptop computers, digital cameras, navigation terminals, televisions, electric vehicles (DVs), etc.

[0052] Figure 2 is a block diagram of a wireless power system (10) according to another exemplary embodiment of the present disclosure.

[0053] refer to Figure 2 In the wireless power system (10), there may be one wireless power receiver (200) or a plurality of wireless power receivers. Figure 1 FIG. 1 shows that the wireless power transmitter (100) and the wireless power receiver (200) transmit and receive power to each other in a one-to-one correspondence (or relationship), but as Figure 2 As shown in the , one wireless power transmitter (100) is also capable of simultaneously transmitting power to a plurality of wireless power receivers (200-1, 200-2, ..., 200-M). Most specifically, in the case of performing wireless power transmission (or transmission) by using a magnetic resonance method, one wireless power transmitter (100) can transmit power to a plurality of wireless power receivers (200-1, 200-2, ..., 200-M) by using a synchronous transmission (or transmission) method or a time division transmission (or transmission) method.

[0054] In addition, despite Figure 1The wireless power transmitter (100) is shown to transmit (or send) power directly to the wireless power receiver (200), but the wireless power system (10) may also be equipped with a separate wireless power transceiver, such as a relay or repeater, for increasing the wireless power transmission distance between the wireless power transmitter (100) and the wireless power receiver (200). In this case, power is delivered from the wireless power transmitter (100) to the wireless power transceiver, and then the wireless power transceiver can transfer the received power to the wireless power receiver (200).

[0055] Hereinafter, the terms "wireless power receiver," "power receiver," and "receiver" mentioned in this specification will refer to the wireless power receiver (200). In addition, the terms "wireless power transmitter," "power transmitter," and "transmitter" mentioned in this specification will refer to the wireless power transmitter (100).

[0056] Figure 3a Exemplary embodiments of various electronic devices employing wireless power transfer systems are shown.

[0057] like Figure 3a As shown in , electronic devices included in the wireless power transmission system are classified according to the amount of transmission power and the amount of reception power. Figure 3a , wearable devices such as smart watches, smart glasses, head-mounted displays (HMDs), smart rings, etc., and mobile electronic devices (or portable electronic devices) such as headphones, remote controllers, smartphones, PDAs, tablet PCs, etc. can adopt low-power (approximately 5W or lower or approximately 20W or lower) wireless charging methods.

[0058] Small / medium-sized electronic devices such as laptop computers, robot vacuum cleaners, TV receivers, audio equipment, vacuum cleaners, monitors, etc. can use medium-power (less than about 50W or less than about 200W) wireless charging methods. Kitchen appliances such as blenders, microwave ovens, rice cookers, etc. and personal transportation devices (or other electric devices or vehicles) such as electric wheelchairs, electric bicycles, electric bikes, electric cars, etc. can use high-power (less than about 2kW or less than about 22kW) wireless charging methods.

[0059] The above description (or Figure 1 The electric device or vehicle (shown) can each include a wireless power receiver, which will be described in detail below. Then, the electric device or vehicle can be charged (or recharged) by wirelessly receiving power from the wireless power transmitter.

[0060] Hereinafter, although the present disclosure will be described based on a mobile device adopting a wireless power charging method, this is merely exemplary, and it should be understood that the wireless charging method according to the present disclosure can be applied to various electronic devices.

[0061] Standards for wireless power transmission (or delivery) include the Wireless Power Consortium (WPC), the Air Fuel Alliance (AFA), and the Power Management Alliance (PMA).

[0062] The WPC standard defines the Baseline Power Profile (BPP) and the Extended Power Profile (EPP). The BPP is related to wireless power transmitters and receivers that support 5W power transmission, while the EPP is related to wireless power transmitters and receivers that support transmission in the power range from greater than 5W to less than 30W.

[0063] Various wireless power transmitters and wireless power receivers, each using different power levels, may be covered by each standard and may be categorized by different power classes or categories.

[0064] For example, the WPC may classify (or categorize) wireless power transmitters and wireless power receivers into PC-1, PC0, PC1, and PC2, and may provide standard documents (or specifications) for each power class (PC). The PC-1 standard covers wireless power transmitters and receivers that provide a guaranteed power of less than 5W. Applications of PC-1 include wearable devices such as smart watches.

[0065] The PC0 standard relates to wireless power transmitters and receivers that provide a guaranteed power of 5W. The PC0 standard includes EPP with a guaranteed power range extended to 30W. Although in-band (IB) communication corresponds to the mandatory communication protocol of PC0, out-of-band (OB) communication, which is used as an optional backup channel, can also be used for PC0. A wireless power receiver can be identified by setting an OB flag within a configuration packet, and the OB flag indicates whether OB is supported. A wireless power transmitter that supports OB can enter the OB switching phase by sending a bit pattern for OB switching as a response to the configuration packet. The response to the configuration packet can correspond to NAK, ND, or a newly defined 8-bit pattern. Applications of PC0 include smartphones.

[0066] The PC1 standard covers wireless power transmitters and receivers that provide guaranteed power ranging from 30W to 150W. The OB corresponds to the mandatory communication channel for PC1, and the IB is used for initialization and link establishment with the OB. A wireless power transmitter can enter the OB switching phase by sending a bit pattern for OB switching in response to a configuration packet. Applications of PC1 include laptop computers and power tools.

[0067] The PC2 standard relates to wireless power transmitters and receivers that provide guaranteed power ranging from 200W to 2kW, and its applications include kitchen appliances.

[0068] As described above, PCs can be distinguished based on the corresponding power levels. In addition, information about whether compatibility between the same PCs is supported can be optional or mandatory. Here, compatibility between the same PCs indicates that power transmission / reception between the same PCs is possible. For example, in a case where a wireless power transmitter corresponding to PC x is capable of performing charging with a wireless power receiver having the same PC x, it can be understood that compatibility between the same PCs is maintained. Similarly, compatibility between different PCs can also be supported. Here, compatibility between different PCs indicates that power transmission / reception between different PCs is also possible. For example, in a case where a wireless power transmitter corresponding to PC x is capable of performing charging with a wireless power receiver having PC y, it can be understood that compatibility between different PCs is maintained.

[0069] Supporting compatibility between PCs corresponds to an extremely important issue in terms of infrastructure establishment and user experience. However, there are various problems in maintaining compatibility between PCs, which will be described below.

[0070] In the case of compatibility between identical PCs, for example, in the case of a wireless power receiver using the laptop charging method (where stable charging is only possible when power is continuously transmitted), even if its corresponding wireless power transmitter has the same PC, it is difficult for the corresponding wireless power receiver to stably receive power from a wireless power transmitter using the power tool method that transmits power discontinuously. Furthermore, in the case of compatibility between different PCs, for example, in the case of a wireless power transmitter with a minimum guaranteed power of 200W transmitting power to a wireless power receiver with a maximum guaranteed power of 5W, the corresponding wireless power receiver may be damaged due to overvoltage. Therefore, it may be inappropriate (or difficult) to use PS as an index / reference standard to express / indicate compatibility.

[0071] Wireless power transmitters and receivers can provide a highly convenient user experience and interface (UX / UI). Specifically, they can offer intelligent wireless charging services, enabled by the UX / UI of smartphones equipped with wireless power transmitters. For these applications, the interface between the smartphone's processor and the wireless charging receiver enables "drop and go" bidirectional communication between the wireless power transmitter and receiver.

[0072] As an example, a user can experience the smart wireless charging service in a hotel. When the user enters a hotel room and places their smartphone on the wireless charger in the room, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When the smartphone is detected to be on the wireless charger, when wireless power is detected to be received, or when the smartphone receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state where it asks the user for consent (opt-in) to supplementary features. To this end, the smartphone may display a message on the screen with or without an alarm sound. An example message may include the phrase "Welcome to ### Hotel. Select "Yes" to enable the smart charging feature: Yes | No, thank you." The smartphone receives input from the user selecting "Yes" or "No, thank you" and executes the next process selected by the user. If "Yes" is selected, the smartphone will send the corresponding information to the wireless charger. The smartphone and wireless charger together perform the smart charging function.

[0073] Smart wireless charging services can also include receiving automatically populated Wi-Fi credentials. For example, the wireless charger sends the Wi-Fi credentials to the smartphone, and the smartphone automatically enters the Wi-Fi credentials received from the wireless charger by running the appropriate application.

[0074] Smart wireless charging services can also include running hotel apps that offer hotel promotions or obtaining remote check-in / check-out and contact information.

[0075] For another example, users can experience the Smart Wireless Charging service while in their vehicle. When a user enters the vehicle and places their smartphone on the wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger sends information about the Smart Wireless Charging service to the smartphone. When the smartphone is detected on the wireless charger, when it detects that it is about to receive wireless power, or when the smartphone receives information about the Smart Wireless Charging service from the wireless charger, the smartphone enters a state where it asks the user to verify their identity.

[0076] In this state, the smartphone automatically connects to the vehicle via WiFi or Bluetooth. The smartphone can display a message on the screen with or without an alarm sound. An example of a message may include the phrase "Welcome to your car. Select "Yes" to sync the device with the in-vehicle controls: Yes | No, thanks". After receiving the user's input selecting "Yes" or "No, thanks", the smartphone executes the next process selected by the user. If "Yes" is selected, the smartphone will send the corresponding information to the wireless charger. In addition, the smartphone and the wireless charger can operate the in-vehicle smart control functions together by driving the in-vehicle application / display software. The user can enjoy the desired music and check regular map locations. The in-vehicle application / display software may include the ability to provide synchronized access to passers-by.

[0077] For another example, a user can experience smart wireless charging at home. When the user enters a room and places their smartphone on a wireless charger, the wireless charger transmits wireless power to the smartphone, and the smartphone receives the wireless power. During this process, the wireless charger sends information about the smart wireless charging service to the smartphone. When the smartphone is detected on the wireless charger, when it detects that it is about to receive wireless power, or when the smartphone receives information about the smart wireless charging service from the wireless charger, the smartphone enters a state where it asks the user for consent (opt-in) for supplementary features. To this end, the smartphone may display a message on the screen with or without an alarm. Examples of this message may include phrases such as "Hi xxx, do you want to enable night mode and protect the building? Yes | No, thank you." The smartphone receives user input indicating a "Yes" or "No, thank you" selection and executes the next process selected by the user. If "Yes" is selected, the smartphone sends the corresponding information to the wireless charger. The smartphone and wireless charger can at least recognize the user's pattern and suggest that the user lock doors and windows, turn off lights, or set an alarm.

[0078] Hereinafter, a "profile" will be newly defined based on an index / reference standard that represents / indicates compatibility. More specifically, it will be understood that by maintaining compatibility between wireless power transmitters and receivers with the same "profile," stable power transmission / reception can be performed, while power transmission / reception between wireless power transmitters and receivers with different "profiles" cannot be performed. "Profiles" can be defined based on compatibility and / or application, regardless of (or independent of) power levels.

[0079] For example, profiles may be divided into 3 different categories such as i) Mobile, ii) Power Tools, and iii) Kitchen.

[0080] As another example, profiles may be categorized into 4 different categories such as i) mobile, ii) power tools, iii) kitchen, and iv) wearable.

[0081] In the case of the "Mobile" profile, the PC can be defined as PC0 and / or PC1, the communication protocol / method can be defined as IB and OB communication, and the operating frequency can be defined as 87 to 205 kHz, while smartphones, laptops, etc. can exist as exemplary applications.

[0082] In the case of the “power tool” profile, the PC may be defined as PC1, the communication protocol / method may be defined as IB communication, the operating frequency may be defined as 87 to 145 kHz, and power tools and the like may exist as exemplary applications.

[0083] In the case of the “kitchen” profile, the PC may be defined as PC2, the communication protocol / method may be defined as NFC-based communication, the operating frequency may be defined as less than 100 kHz, and kitchen / home appliances, etc. may exist as exemplary applications.

[0084] In the case of the power tool and kitchen profile, NFC communication can be used between the wireless power transmitter and the wireless power receiver. The wireless power transmitter and the wireless power receiver can confirm that they are NFC devices by exchanging WPC NFC Data Exchange Profile Format (NDEF).

[0085] Figure 3b An example of WPC NDEF in a wireless power transmission system is shown.

[0086] refer to Figure 3b 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) mobile and computing, ii) power tool, and iii) kitchen. The upper nibble in the version field indicates the major version and the lower nibble indicates the minor version. In addition, the profile-specific data defines content specific to the kitchen.

[0087] In the case of the “wearable” profile, the PC may be defined as PC-1, the communication protocol / method may be defined as IB communication, the operating frequency may be defined as 87 to 205 kHz, and a wearable device worn by a user, etc. may exist as an exemplary application.

[0088] Maintaining compatibility between the same profiles may be mandatory, and maintaining compatibility between different profiles may be optional.

[0089] The above-mentioned profiles (mobile profile, power tool profile, kitchen profile, and wearable profile) may be summarized and expressed as first to nth profiles, and new profiles may be added / replaced according to the WPC standard and exemplary embodiments.

[0090] When the profile is defined as described above, the wireless power transmitter can selectively transmit power only to wireless power receivers that have the same profile as the wireless power transmitter, thereby enabling more stable power transmission. Furthermore, since the load (or burden) on the wireless power transmitter can be reduced and power transmission to incompatible wireless power receivers is not attempted, the risk of damage to the wireless power receiver can be reduced.

[0091] PC1 of the "mobile" profile can be defined by deriving it from optional extensions such as OOB based on PC0. Also, the "power tool" profile can be defined as a simple modified version of the PC1 "mobile" profile. In addition, although profiles have been defined so far for the purpose of maintaining compatibility between the same profiles, in the future, technology may develop to a level that maintains compatibility between different profiles. A wireless power transmitter or wireless power receiver can use various methods to notify (or announce) its profile to its peer.

[0092] In the AFA standard, wireless power transmitters are called power transmission units (PTUs), and wireless power receivers are called power reception units (PRUs). PTUs are categorized into multiple levels as shown in Table 1, and PRUs are categorized into multiple levels as shown in Table 2.

[0093] [Table 1]

[0094] <![CDATA[P TX_IN_MAX ]]> Minimum Category Support Requirements Minimum value of the maximum number of supported devices Level 1 2W 1x Category 1 1x Category 1 Level 2 10W 1x Category 3 2x Category 2 Level 3 16W 1x Category 4 2x Category 3 Level 4 33W 1x Category 5 3x Category 3 Level 5 50W 1x Category 6 4x Category 3 Level 6 70W 1x Category 7 5x Category 3

[0095] [Table 2]

[0096]

[0097]

[0098] As shown in Table 1, the maximum output power capability of a Class n PTU can be equal to or greater than that of the corresponding Class PTU. TX_IN_MAX A PRU cannot draw power higher than the power level specified in the corresponding class.

[0099] Figure 4 is a block diagram of a wireless power transmission system according to another exemplary embodiment of the present disclosure.

[0100] refer to Figure 4 , a wireless power transmission system (10) includes a mobile device (450) that wirelessly receives power and a base station (400) that wirelessly transmits power.

[0101] As a device for providing inductive power or resonant power, the base station (400) may include at least one of a wireless power transmitter (100) and a system unit (405). The wireless power transmitter (100) may transmit inductive power or resonant power and may control the transmission. The wireless power transmitter (100) may include a power conversion circuit (110) that converts electrical energy into a power signal by generating a magnetic field via one or more primary coils and a communication and control unit (120) that controls communication and power transmission between wireless power receivers (200) so as to transmit an appropriate (or suitable) level of power. The system unit (405) may perform input power supply, control of multiple wireless power transmitters, and other operation controls of the base station (400) (e.g., user interface control).

[0102] The primary coil can generate an electromagnetic field by using alternating current power (or voltage or current). The primary coil is supplied with alternating current power (or voltage or current) of a specific frequency, which is output from the power conversion circuit (110). Therefore, the primary coil can generate a magnetic field of a specific frequency. A non-radial or radial magnetic field can be generated. In addition, the wireless power receiver (200) receives the generated magnetic field and then generates current. In other words, the primary coil transmits power wirelessly.

[0103] In magnetic induction methods, the primary and secondary coils can have any suitable random shape. For example, the primary and secondary coils can correspond to copper wire wrapped around a highly permeable material (e.g., ferrite or amorphous metal). The primary coil can also be referred to as a primary magnetic core, a primary winding, a primary loop antenna, etc. Furthermore, the secondary coil can also be referred to as a secondary magnetic core, a secondary winding, a secondary loop antenna, a pickup antenna, etc.

[0104] When using a magnetic resonance method, a primary coil and a 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 may be determined by the inductance of the coil and the capacitance of the capacitor. Here, the coil may be formed into a loop shape. In addition, a magnetic core may be placed within the loop. The magnetic core may include a physical magnetic core such as a ferrite core or an air magnetic core.

[0105] Energy transmission (or transfer) between the primary resonant antenna and the secondary resonant antenna can be performed through a resonance phenomenon occurring in a magnetic field. When a near field corresponding to the resonant frequency appears in the resonant antenna, and when another resonant antenna is present near the corresponding resonant antenna, the resonance phenomenon refers to efficient energy transfer occurring between two mutually coupled resonant antennas. When a magnetic field corresponding to the resonant frequency is generated between the primary resonant antenna and the secondary resonant antenna, the primary resonant antenna and the secondary resonant antenna resonate with each other. Therefore, in general, compared to the case where the magnetic field generated from the primary antenna is radiated into free space, the magnetic field is more efficiently concentrated toward the second resonant antenna. Therefore, energy can be efficiently transferred from the first resonant antenna to the second resonant antenna. The magnetic induction method can be implemented similarly to the magnetic resonance method. However, in this case, the frequency of the magnetic field is not required to be the resonant frequency. However, in the magnetic induction method, the loops configuring the primary coil and the secondary coil are required to match each other, and the distance between the loops should be very close.

[0106] Although not shown in the drawings, the wireless power transmitter (100) may further include a communication antenna. In addition to magnetic field communication, the communication antenna may transmit and / or receive communication signals by using a communication carrier. For example, the communication antenna may transmit and / or receive communication signals corresponding to WiFi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0107] The communication and control unit (120) can send information to the wireless power receiver (200) and / or receive information from the wireless power receiver (200). The communication and control unit (120) can include at least one of an IB communication module and an OB communication module.

[0108] The IB communication module can send and / or receive information by using electromagnetic waves that use a specific frequency as its center frequency. For example, the communication and control unit (120) can perform in-band (IB) communication by using a primary coil to send communication information about the operating frequency of wireless power transmission or by using a primary coil to receive communication information about the operating frequency. At this time, the communication and control unit (120) can load information into the electromagnetic wave or interpret the information carried by the electromagnetic wave by using a modulation scheme such as binary phase shift keying (BPSK), frequency shift keying (FSK) or amplitude shift keying (ASK) or a coding scheme such as Manchester coding or non-return-to-zero level (NZR-L) coding. By using the above-mentioned IB communication, the communication and control unit (120) can send and / or receive information at a data transmission rate of several kbps over a distance of several meters.

[0109] The OB communication module can also perform out-of-band communication via a communication antenna. For example, the communication and control unit (120) can be configured for a near field communication module. Examples of the near field communication module can include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0110] The communication and control unit (120) can control the overall operation of the wireless power transmitter (100). The communication and control unit (120) can perform calculations and processing of various information and can also control each configuration element of the wireless power transmitter (100).

[0111] The communication and control unit (120) may be implemented in a computer or similar device such as hardware, software, or a combination thereof. When implemented in hardware, the communication and control unit (120) may be provided as an electronic circuit that performs a control function by processing an electrical signal. Also, when implemented in software, the communication and control unit (120) may be provided as a program that operates the communication and control unit (120).

[0112] By controlling the operating point, the communication and control unit (120) can control the transmission power. The controlled operating point can correspond to a combination of frequency (or phase), duty cycle, duty ratio, and voltage amplitude. The communication and control unit (120) can control the transmission power by adjusting any one of the frequency (or phase), duty cycle, duty ratio, and voltage amplitude. In addition, the wireless power transmitter (100) can provide a constant level of power, and the wireless power receiver (200) can control the level of received power by controlling the resonant frequency.

[0113] The mobile device (450) includes a wireless power receiver (200) that receives wireless power through a secondary coil and a load (455) that receives and stores the power received by the wireless power receiver (200) and supplies the received power to the device.

[0114] The wireless power receiver (200) may include a power pickup circuit (210) and a communication and control unit (220). The power pickup circuit (210) may receive wireless power through a secondary coil and may convert the received wireless power into electrical energy. The power pickup circuit (210) may rectify an alternating current (AC) signal received through the secondary coil and convert the rectified signal into a direct current (DC) signal. The communication and control unit (220) may control the transmission and reception of wireless power (transmission and reception of power).

[0115] The secondary coil can receive wireless power transmitted from the wireless power transmitter (100). The secondary coil can receive power by using the magnetic field generated in the primary coil. Here, when a specific frequency corresponds to a resonance frequency, magnetic resonance can occur between the primary coil and the secondary coil, thereby allowing power to be transmitted more efficiently.

[0116] Despite Figure 4 Although not shown, the communication and control unit (220) may further include a communication antenna. The communication antenna may send and / or receive communication signals using a communication carrier other than magnetic field communication. For example, the communication antenna may send and / or receive communication signals corresponding to Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, etc.

[0117] The communication and control unit (220) can transmit information to the wireless power transmitter (100) and / or receive information from the wireless power transmitter (100). The communication and control unit (220) can include at least one of an IB communication module and an OB communication module.

[0118] The IB communication module can transmit and / or receive information by using electromagnetic waves that use a specific frequency as their center frequency. For example, the communication and control unit (220) can perform IB communication by loading information into the electromagnetic waves and transmitting the information by using the secondary coil or receiving the electromagnetic waves carrying the information by using the secondary coil. In this case, the communication and control unit (120) can load the information into the electromagnetic waves or interpret the information carried by the electromagnetic waves by using a modulation scheme such as binary phase shift keying (BPSK), frequency shift keying (FSK) or amplitude shift keying (ASK) or a coding scheme such as Manchester coding or non-return-to-zero level (NZR-L) coding. By using the above-mentioned IB communication, the communication and control unit (220) can transmit and / or receive information at a data transmission rate of several kbps over a distance of several meters.

[0119] The OB communication module can also perform out-of-band communication via the communication antenna.For example, the communication and control unit (220) can be configured for a near field communication module.

[0120] Examples of the near field communication module may include communication modules such as Wi-Fi, Bluetooth, Bluetooth LE, ZigBee, NFC, and the like.

[0121] The communication and control unit (220) can control the overall operation of the wireless power receiver (200). The communication and control unit (220) can perform calculations and processing of various information and can also control each configuration element of the wireless power receiver (200).

[0122] The communication and control unit (220) may be implemented in a computer or similar device such as hardware, software, or a combination thereof. When implemented in hardware, the communication and control unit (220) may be provided as an electronic circuit that performs control functions by processing electrical signals. Furthermore, when implemented in software, the communication and control unit (220) may be provided as a program that operates the communication and control unit (220).

[0123] Hereinafter, a coil or a coil unit includes a coil and at least one device close to the coil, and the coil or the coil unit may also be referred to as a coil assembly, a coil unit, or a unit.

[0124] Figure 5 It is a state transition diagram used to describe the wireless power transfer process.

[0125] refer to Figure 5 , power transmission (or transmission) from a wireless power transmitter to a wireless power receiver according to an exemplary embodiment of the present disclosure can be roughly 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 transmission phase (560) and a renegotiation phase (570).

[0126] If a specific error or specific event is detected when initiating power transfer or while maintaining power transfer, the selection phase (510) may include shift phases (or steps) - reference numerals S502, S504, S508, S510 and S512. Here, the specific error or specific event will be specified in the following description. In addition, during the selection phase (510), the wireless power transmitter may monitor whether an object is present on the interface surface. If the wireless power transmitter detects that an object is placed on the interface surface, the processing step may shift to the ping phase (520). During the selection phase (510), the wireless power transmitter may transmit a simulated ping having a power signal (or pulse) corresponding to an extremely short duration, and may detect whether an object is within the effective area of ​​the interface surface based on the current change in the transmitting coil or the primary coil.

[0127] In the event that an object is sensed (or detected) in the selection phase (510), the wireless power transmitter may measure the quality factor of the wireless power resonant circuit (e.g., a power transmission coil and / or a resonant capacitor). According to an exemplary embodiment of the present disclosure, during the selection phase (510), the wireless power transmitter may measure the quality factor in order to determine, together with the wireless power receiver, whether a foreign object is present in the charging area. In the coil provided in the wireless power transmitter, the components of the inductance and / or series resistance may decrease due to changes in the environment, and due to such decrease, the value of the quality factor may also decrease. In order to determine whether a foreign object is present or not by using the measured quality factor value, the wireless power transmitter may receive a reference quality factor value from the wireless power receiver, the reference quality factor value being measured in advance in a state where no foreign object is placed in the charging area. The wireless power transmitter may determine whether a foreign object is present or not by comparing the measured quality factor value with the reference quality factor value received during the negotiation phase (540). However, in the case of a wireless power receiver with a low reference quality factor value—for example, a wireless power receiver may have a low reference quality factor value due to its type, purpose, characteristics, etc.—in the presence of foreign matter, the difference between the reference quality factor value and the measured quality factor value is small (or not large), so there may be a problem in that the presence of foreign matter cannot be easily determined. Therefore, in this case, other determination factors should be further considered, or the presence of foreign matter should be determined by using another method.

[0128] According to another exemplary embodiment of the present disclosure, when an object is sensed (or detected) in the selection phase (510), the wireless power transmitter may measure a quality factor value within a specific frequency region (e.g., an operating frequency region) in order to determine, together with the wireless power receiver, whether a foreign object is present in the charging area. In a coil provided in the wireless power transmitter, the components of inductance and / or series resistance may decrease due to changes in the environment, and due to such a decrease, the resonant frequency of the coil of the wireless power transmitter may change (or shift). More specifically, the quality factor peak frequency corresponding to the frequency at which the maximum quality factor value is measured within the operating frequency band may shift (or shift).

[0129] In the ping phase (520), if the wireless power transmitter detects the presence of an object, the transmitter activates (or wakes up) the receiver and transmits a digital ping for identifying whether the detected object corresponds to the wireless power receiver. During the ping phase (520), if the wireless power transmitter fails to receive a response signal (e.g., a signal strength packet) to the digital ping from the receiver, the process may return to the selection phase (510). In addition, during the ping phase (520), if the wireless power transmitter receives a signal (e.g., a charge completion packet) from the receiver indicating that power transfer is complete, the process may return to the selection phase (510).

[0130] If the ping phase (520) is complete, the wireless power transmitter may transition to an identification and configuration phase (530) for identifying the receiver and for collecting configuration and status information.

[0131] In the identification and configuration phase (530), if the wireless power transmitter receives an unwanted packet (i.e., an unexpected packet), or if the wireless power transmitter fails to receive a packet during a predetermined time period (i.e., a timeout), or if a packet transmission error occurs (i.e., a transmission error), or if no power contract is configured for transmission (i.e., no power transmission contract), the wireless power transmitter may transition to the selection phase (510).

[0132] The wireless power transmitter may confirm (or verify) whether it is necessary to enter the negotiation phase (540) based on the negotiation field value of the configuration packet received during the identification and configuration phase (530). Based on the verification result, if negotiation is required, the wireless power transmitter enters the negotiation phase (540) and may then perform a predetermined FOD detection process. Conversely, if negotiation is not required, the wireless power transmitter may immediately enter the power transmission phase (560).

[0133] During the negotiation phase (540), the wireless power transmitter may receive a foreign object detection (FOD) status packet including a reference quality factor value. Alternatively, the wireless power transmitter may receive a FOD status packet including a reference peak frequency value. Alternatively, the wireless power transmitter may receive a status packet including both a reference quality factor value and a reference peak frequency value. In this case, the wireless power transmitter may determine a quality factor threshold for FO detection based on the reference quality factor value. The wireless power transmitter may determine a peak frequency threshold for FO detection based on the reference peak frequency value.

[0134] The wireless power transmitter can detect the presence of a FO in the charging area by using the determined quality factor threshold for FO detection and the currently measured quality factor value (i.e., the quality factor value measured before the ping phase). The wireless power transmitter can then control the transmission power based on the FO detection result. For example, if FO is detected, power transmission can be stopped. However, the present invention is not limited to this.

[0135] The wireless power transmitter can detect the presence of FO in the charging area by using the determined peak frequency threshold for FO detection and the currently measured peak frequency value (i.e., the peak frequency value measured before the ping phase). The wireless power transmitter can then control the transmission power based on the FO detection result. For example, if FO is detected, power transmission can be stopped. However, the present invention is not limited to this.

[0136] In the event that FO is detected, the wireless power transmitter may return to the selection phase (510). In contrast, in the event that FO is not detected, the wireless power transmitter may proceed to the calibration phase (550) and may then enter the power transmission phase (560). More specifically, in the event that FO is not detected, the wireless power transmitter may determine the intensity of the received power received by the receiving end during the calibration phase (550) and may measure the power loss in the receiving end and the transmitting end in order to determine the intensity of the power transmitted from the transmitting end. In other words, during the calibration phase (550), the wireless power transmitter may estimate the power loss based on the difference between the transmission power of the transmitting end and the reception power of the receiving end. A wireless power transmitter according to an exemplary embodiment of the present invention may calibrate a threshold for FOD detection by applying the estimated power loss.

[0137] In the power transfer stage (560), if the wireless power transmitter receives an unwanted packet (i.e., an unexpected packet), or if the wireless power transmitter fails to receive a packet during a predetermined time period (i.e., a timeout), or if a predetermined power transfer contract is violated (i.e., a power transfer contract violation), or if charging is completed, the wireless power transmitter may transition to the selection stage (510).

[0138] In addition, in the power transfer phase (560), if the wireless power transmitter needs to reconfigure the power transfer contract according to the state change in the wireless power transmitter, the wireless power transmitter may transition to the renegotiation phase (570). At this time, if the renegotiation is successfully completed, the wireless power transmitter may return to the power transfer phase (560).

[0139] In this embodiment, the calibration step 550 and the power transmission stage 560 are divided into separate steps, but the calibration step 550 may be integrated into the power transmission stage 560. In this case, the operations in the calibration step 550 may be performed in the power transmission stage 560.

[0140] The power transfer contract described above can be configured based on the status and characteristics of the wireless power transmitter and receiver. For example, wireless power transmitter status information may include information about the maximum amount of transmittable power and the maximum number of receivers that can be accommodated. Receiver status information may also include information about the required power.

[0141] Figure 6 A power control method according to an exemplary embodiment of the present disclosure is shown.

[0142] like Figure 6 As shown, in the power transmission phase (560), the wireless power transmitter (100) and the wireless power receiver (200) can control the amount (or size) of power transmitted by alternating power transmission and / or reception with communication. The wireless power transmitter and the wireless power receiver operate at a specific control point. The control point indicates the combination of voltage and current provided from the output terminal of the wireless power receiver when performing power transmission.

[0143] More specifically, the wireless power receiver selects a desired control point, a desired output current / voltage, the temperature at a specific location of the mobile device, and the like, and additionally determines the actual control point at which the receiver is currently operating. The wireless power receiver calculates a control error value using the desired control point and the actual control point. The wireless power receiver then transmits the calculated control error value as a control error packet to the wireless power transmitter.

[0144] In addition, the wireless power transmitter can use the received control error packet to configure / control a new operating point—amplitude, frequency, and duty cycle—to control power transmission. The control error packet can then be transmitted / received at constant intervals during the power transmission phase. According to an exemplary embodiment, when the wireless power receiver attempts to reduce the wireless power transmitter's current, the wireless power receiver can transmit the control error packet by setting the control error value to a negative number. Furthermore, when the wireless power receiver attempts to increase the wireless power transmitter's current, the wireless power receiver transmits the control error packet by setting the control error value to a positive number. During the sensing mode, the wireless power receiver can control power transmission by transmitting the control error packet to the wireless power transmitter as described above.

[0145] In the resonance mode, which will be described in detail below, the device can be operated by using a method different from that of the induction mode. In the resonance mode, one wireless power transmitter should be able to serve multiple wireless power receivers at the same time. However, in the case where the power transmission is controlled only as in the induction mode, it may be difficult to control the power transmission of another wireless power receiver because the transmitted power is controlled by the communication established with one wireless power receiver. Therefore, in the resonance mode according to the present invention, the following method is used: the amount of received power is controlled by causing the wireless power transmitter to normally transmit (or send) basic power and causing the wireless power receiver to control its own resonant frequency. However, even during operation in the resonance mode, the above is not completely excluded. Figure 6 Furthermore, additional control of the transmit power can be achieved by using Figure 6 method to execute.

[0146] Figure 7 This is a block diagram of a wireless power transmitter according to another exemplary embodiment of the present disclosure. This may pertain to a wireless power transmission system operating in magnetic resonance mode or shared mode. Shared mode may refer to a mode in which many-to-one (or one-to-many) communication and charging are performed between a wireless power transmitter and a wireless power receiver. Shared mode may be implemented using either a magnetic induction method or a resonance method.

[0147] refer to Figure 7 The wireless power transmitter (700) may include at least one of a cover (720) covering the coil assembly, a power adapter (730) supplying power to the power transmitter (740), the power transmitter (740) transmitting wireless power, and a user interface (750) providing information related to the power transmission process and other related information. More specifically, the user interface (750) may be optionally included or may be included as another user interface (750) of the wireless power transmitter (700).

[0148] 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), and a control circuit (710).

[0149] The coil assembly (760) includes at least one primary coil for generating a magnetic field. Also, the coil assembly (760) may be referred to as a coil unit.

[0150] The impedance matching circuit (770) can provide impedance matching between the inverter and the primary coil(s). The impedance matching circuit (770) can generate resonance from an appropriate frequency that increases the current of the primary coil(s). In a multi-coil power transmitter (740), the impedance matching circuit can additionally include a multiplexer that routes signals from the inverter to a subset of the primary coils. The impedance matching circuit can also be referred to as an oscillating circuit.

[0151] The impedance matching circuit (770) may include a capacitor, an inductor, and a switching device for switching the connection between the capacitor and the inductor. Impedance matching can be performed by detecting a reflected wave of wireless power transmitted (or sent) through the coil assembly (760) and switching the switching device based on the detected reflected wave, thereby adjusting the connection state of the capacitor or inductor, adjusting the capacitance of the capacitor, or adjusting the inductance of the inductor. In some cases, impedance matching can be achieved even if the impedance matching circuit (770) is omitted. This specification also includes an exemplary embodiment of a wireless power transmitter (700) in which the impedance matching circuit (770) is omitted.

[0152] The inverter (780) can convert a DC input into an AC signal. The inverter (780) can operate as a half-bridge inverter or a full-bridge inverter to generate a duty cycle and pulse wave with adjustable frequency. In addition, the inverter can include multiple stages to adjust the input voltage level.

[0153] The communication circuit (790) can perform communication with the power receiver. The power receiver performs load modulation to transmit information and requests corresponding to the power transmitter. Therefore, the power transmitter (740) can use the communication circuit (790) to monitor the amplitude and / or phase of the current and / or voltage of the primary coil to demodulate the data sent from the power receiver.

[0154] In addition, the power transmitter (740) can control the output power by using a frequency shift keying (FSK) method or the like so that data can be transmitted through the communication circuit (790).

[0155] The control circuit (710) can control the communication and power transmission (or delivery) of the power transmitter (740). The control circuit (710) can control the power transmission by adjusting the above-mentioned operating point. The operating point can be determined by at least any one of the operating frequency, duty cycle, and input voltage, for example.

[0156] The communication circuit (790) and the control circuit (710) may be provided as separate units / devices / chip sets, respectively, or may be provided as one unit / device / chip set.

[0157] Figure 8A wireless power receiver according to another exemplary embodiment of the present disclosure is shown. This may belong to a wireless power transmission system operating in magnetic resonance mode or sharing mode.

[0158] refer to Figure 8 The wireless power receiver (800) may include at least one of a user interface (820) that provides information related to a power transmission process and other related information, a power receiver (830) that receives wireless power, a load circuit (840), and a base (850) that supports and covers a coil assembly. More specifically, the user interface (820) may be optionally included or may be included as another user interface (820) of the wireless power receiver (800).

[0159] 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), and a control circuit (810).

[0160] The power converter (860) can convert the AC power received from the secondary coil into a voltage and current suitable for the load circuit. According to an exemplary embodiment, the power converter (860) may include a rectifier. The rectifier can rectify the received wireless power and can convert the power from alternating current (AC) to direct current (DC). The rectifier can convert the alternating current into direct current using a diode or a transistor, and then the rectifier can use a capacitor and a resistor to smooth the converted current. Here, a full-wave rectifier, a half-wave rectifier, a voltage doubler, etc. implemented as a bridge circuit can be used as a rectifier. In addition, the power converter can adapt to the reflected impedance of the power receiver.

[0161] The impedance matching circuit (870) can provide impedance matching between the secondary coil and the combination of the power converter (860) and the load circuit (840). According to an exemplary embodiment, the impedance matching circuit can generate a resonance of approximately 100 kHz, which can enhance power transmission. The impedance matching circuit (870) can include a capacitor, an inductor, and a switching device that switches the combination of the capacitor and the inductor. Impedance matching can be performed by controlling the switching devices 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, impedance matching can be achieved even if the impedance matching circuit (870) is omitted. This specification also includes an exemplary embodiment of a wireless power receiver (200) in which the impedance matching circuit (870) is omitted.

[0162] The coil assembly (880) includes at least one secondary coil and, optionally, may also include elements for shielding metal parts of the receiver from magnetic fields.

[0163] The communication circuit (890) may perform load modulation to communicate requests and other information to the power transmitter.

[0164] To this end, the power receiver (830) may perform switching of resistors or capacitors to change the reflected impedance.

[0165] The control circuit (810) can control the received power. To this end, the control circuit (810) can determine / calculate the difference between the actual operating point and the desired operating point of the power receiver (830). Then, by executing a request to adjust the reflected impedance of the power transmitter and / or adjust the operating point of the power transmitter, the difference between the actual operating point and the desired operating point can be adjusted / reduced. When the difference is minimized, optimal power reception can be performed.

[0166] The communication circuit (890) and the control circuit (810) may be provided as different devices / chip sets, or may be provided as one device / chip set.

[0167] Figure 9 Operation states of a wireless power transmitter and a wireless power receiver in a sharing mode according to an exemplary embodiment of the present disclosure are shown.

[0168] refer to Figure 9 , a wireless power receiver operating in a sharing mode may operate in any one of a selection phase (1100), an introduction phase (1110), a configuration phase (1120), a negotiation phase (1130), and a power transfer phase (1140).

[0169] First, the wireless power transmitter according to an exemplary embodiment of the present disclosure may transmit a wireless power signal to detect a wireless power receiver. More specifically, the process of detecting a wireless power receiver using the wireless power signal may be referred to as a simulated ping.

[0170] In addition, the wireless power receiver that receives the wireless power signal may enter the selection phase ( 1100 ). As described above, the wireless power receiver that enters the selection phase ( 1100 ) may detect the presence or absence of the FSK signal in the wireless power signal.

[0171] In other words, the wireless power receiver may perform communication by using any one of the exclusive mode and the shared mode according to the presence or absence of the FSK signal.

[0172] More specifically, in case that the FSK signal is included in the wireless power signal, the wireless power receiver may operate in the sharing mode, otherwise the wireless power receiver may operate in the exclusive mode.

[0173] When the wireless power receiver operates in shared mode, the wireless power receiver may enter the introduction phase (1110). In the introduction phase (1110), the wireless power receiver may send a control information (CI) packet to the wireless power transmitter to transmit the control information packet during the configuration phase, negotiation phase, and power transmission phase. The control information packet may have a header and control-related information. For example, in the control information packet, the header may correspond to 0X53.

[0174] In the introduction phase (1110), the wireless power receiver attempts to request a free time slot for transmitting a control information (CI) packet during the subsequent configuration phase, negotiation phase, and power transfer phase. At this point, the wireless power receiver selects a free time slot and transmits an initial CI packet. If the wireless power transmitter sends an ACK in response to the corresponding CI packet, the wireless power transmitter enters the configuration phase. If the wireless power transmitter sends a NACK in response to the corresponding CI packet, this indicates that another wireless power receiver is currently communicating through the configuration and negotiation phases. In this case, the wireless power receiver retries to request a free time slot.

[0175] If the wireless power receiver receives an ACK as a response to the CI packet, the wireless power receiver can determine the position of the dedicated time slot in the frame by counting the remaining synchronization time slots until the initial frame synchronization. In all subsequent time slot-based frames, the wireless power receiver transmits the CI packet through the corresponding time slot.

[0176] If the wireless power transmitter authorizes the wireless power receiver to enter the configuration phase, the wireless power transmitter provides a series of lock slots dedicated to the wireless power receiver. This ensures that the wireless power receiver can proceed to the configuration phase without any conflicts.

[0177] The wireless power receiver transmits a sequence of data packets, such as two identification data packets (IDHI and IDLO), using the locked time slots. Once this phase is complete, the wireless power receiver enters the negotiation phase. During the negotiation phase, the wireless power transmitter continues to provide the locked time slots exclusively for use by the wireless power receiver. This ensures that the wireless power receiver can proceed to the negotiation phase without any conflicts.

[0178] The wireless power receiver transmits one or more negotiation data packets using the corresponding lock slots, and the transmitted negotiation data packets may be mixed with dedicated data packets. Ultimately, the corresponding sequence ends (or is completed) with a specific request (SRQ) packet. When the corresponding sequence is completed, the wireless power receiver enters the power transfer phase, and the wireless power transmitter stops providing lock slots.

[0179] During the power transfer phase, the wireless power receiver transmits a CI packet using the allocated time slot and then receives power. The wireless power receiver may include a regulator circuit. This regulator circuit may be included in the communication / control unit. The wireless power receiver can use the regulator circuit to self-regulate the reflected impedance of the wireless power receiver. In other words, the wireless power receiver can adjust the reflected impedance to the amount of power requested by the external load. This can prevent over-receiving power and overheating.

[0180] In the sharing mode, since the wireless power transmitter may not perform power regulation in response to a received CI packet (depending on the operation mode), control may be required in this case to prevent an overvoltage condition.

[0181] Hereinafter, authentication between a wireless power transmitting device and a wireless power receiving device will be disclosed.

[0182] Assume that when the wireless power transmitting device transmits wireless power to the wireless power receiving device, a foreign object is located between the wireless power receiving device and the wireless power transmitting device. In this case, the foreign object absorbs part of the magnetic field. In other words, the foreign object receives part of the wireless power transmitted by the wireless power transmitting device, and the wireless power receiving device receives the remaining wireless power. In terms of power transmission efficiency, the loss of transmission power is as much as the power or energy absorbed by the foreign object. As mentioned above, because the presence of foreign matter and power loss (P loss ) establish a causal relationship between them, so the wireless power transmission device can detect foreign objects based on how much power loss occurs. The above foreign object detection method can be called a foreign object detection method based on power loss.

[0183] The power loss caused by foreign matter can be defined as the power lost by the power transmitted from the wireless power transmission device (P transmitted ) minus the actual power (P) received by the wireless power receiving device received ) is obtained. Because the wireless power transmission device already knows the power it transmits (P transmitted ), so once the wireless power transmitting device knows the actual power (P received ), the power loss can be calculated. To this end, the wireless power receiving device can periodically send the received power data packet (RP) to the wireless power transmitting device to transmit the power (P received ) notifies the wireless power transmitting device.

[0184] Meanwhile, although the wireless power transmitting device and the wireless power receiving device are composed of various internal circuit elements and constitute independent devices, because these devices perform wireless power transmission through magnetic coupling between them, they constitute a wireless power transmission system. The power transmission characteristic uniquely determines the amount of power transmitted by the wireless power transmitting device (transmitted power) and the amount of power received by the wireless power receiving device (received power). For example, the power transmission characteristic can be described by a ratio or function of the transmitted power and the received power. Therefore, the wireless power transmitting device, knowing the power transmission characteristic in advance, can predict the amount of power received by the wireless power receiving device based on the wireless power transmitted by the wireless power transmitting device. Suppose that the actual received power reported by the wireless power receiving device is less than the received power predicted based on the power transmission characteristic; in this case, it can be assumed that 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 this case. In this case, a foreign object detection method based on power loss can determine the presence of a foreign object. In this way, because the power loss used to detect a foreign object is also determined based on the power transmission characteristic, it is necessary to correctly understand the power transmission characteristic to increase the reliability of foreign object detection.

[0185] Power transfer characteristics depend on factors inherent to the environment or device transmitting wireless power. Wireless power transmitting and receiving devices typically use power calibration at the start of wireless power transfer to understand the power transfer characteristics of any given wireless charging environment. Once power transfer characteristics are identified or configured through power calibration, foreign object detection can be performed accordingly.

[0186] The power transfer characteristics may also depend on changes in the load or changes in the magnetic coupling strength. For example, when the wireless power receiving device adopts multiple load steps or a changing load (or an increased load) or when the magnetic coupling strength changes due to a change in the position of the wireless power transmitting and receiving devices, at least part of the power transfer characteristics may change. When at least part of the power transfer characteristics changes, at least part of the power calibration parameters configured according to the previous power transfer characteristics become invalid. In addition, power loss and foreign object detection performed according to at least part of the configured power calibration parameters are no longer valid. Therefore, additional power calibration is required that is applicable to the changed power transfer characteristics.

[0187] When a foreign object is detected due to power loss, the accuracy of the reception power value that the wireless power receiving device periodically transmits through the reception power packet is essential; the WPC Qi specification requires high accuracy as shown in Table 3.

[0188] [Table 3]

[0189] Estimated received power <![CDATA[ΔP r ]]> unit <![CDATA[Pr (est) ≤5W]]> 350 mW <![CDATA[5W<Pr (est) ≤10W]]> 500 mW <![CDATA[10W<Pr (est) ]]> 750 mW

[0190] Referring to Table 3, when the wireless power receiving device receives wireless power greater than 5 W, the resolution of the received power value required by the wireless power receiving device is greater than 500 mW. Therefore, a problem arises in that a foreign object consuming less than 500 mW cannot be detected with the above-mentioned resolution.

[0191] In order to compensate for the accuracy of the received power value during transmission and reception of wireless power greater than 5 W, a two-point power calibration method is used.

[0192] Figure 10 is a state diagram illustrating a two-point power calibration method, and Figure 11 is a graph illustrating a power calibration curve according to a two-point power calibration method.

[0193] refer to Figure 10 ,After completing the negotiation phase, the wireless power receiving device sends a first ,received power packet (RP / 1) and a second received power packet (RP / 2) at the beginning of the power ,transmission step, to allow the wireless power transmitting device to construct a two-point ,power calibration curve.

[0194] More specifically, the wireless power receiving device transmits a first reception power packet (RP / 1) including information on a first calibration data point to the wireless power transmitting device SR1.

[0195] The first received power packet (RP / 1) includes a mode field and an estimated received power value field (see Figure 13 ). The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the first received power packet (RP / 1) including information about the first calibration data point through the value of the mode field of the first received power packet (RP / 1), and confirm the first calibration data point through the value of the estimated received power value field of the first received power packet (RP / 1).

[0196] The first calibration data point is the starting point of the power calibration 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, and may be a received power value received by the wireless power receiving device under a light load condition. The light load condition may indicate a situation where a load (e.g., a battery) is not electrically connected to the wireless power receiving device.

[0197] At the same time, the wireless power receiving device transmits a control error (CE) packet to the wireless power transmitting device, where the CE packet includes a control error value. The control error value includes information about the deviation between the target operating point and the actual operating point of the wireless power receiving device. For example, when the CE value is positive, it indicates that the actual operating point is lower than the target operating point, and the wireless power transmitting device that receives the CE value increases the power of the wireless power it transmits. On the other hand, if the CE value is negative, it indicates that the actual operating point is higher than the target operating point, and the wireless power transmitting device that receives the CE value decreases the power of the wireless power it transmits.

[0198] The wireless power transmission device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds ST1 with ACK or NAK in response to the first received power data packet (RP / 1). More specifically, the wireless power transmission device determines whether the power level is stable at the first calibration data point based on the control error value. For example, when the control error value is less than 3, the wireless power transmission device can determine that the power level is stable and the wireless power receiving device has reached the desired target operating point; and responds with ACK in response to the first received power packet (RP / 1). When the control error value is greater than 3, the wireless power transmission device can determine that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and responds with NAK in response to the first received power packet (RP / 1).

[0199] The wireless power receiving device continues to send the first receive power packet (RP / 1) until it receives an ACK SR1 from the wireless power transmitting device. In addition, in order to stabilize the power level at the first calibration data point, the wireless power receiving device also repeatedly sends a control error packet to the wireless power transmitting device.

[0200] After the power level stabilizes at the first calibration data point and an ACK is received from the wireless power transmitting device in response to the first receive power packet (RP / 1), the wireless power receiving device sends a second receive power packet (RP / 2) including information about the second calibration data point to the wireless power transmitting device SR2.

[0201] The second receiving power packet (RP / 2) also includes a mode field and an estimated receiving power value field (see Figure 13 ). The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the second received power packet (RP / 2) including information about the second calibration data point through the value of the mode field of the second received power packet (RP / 2), and confirm the second calibration data point through the value of the estimated received power value field of the second received power packet (RP / 2).

[0202] The second calibration data point can be used to construct a power calibration curve corresponding to a power level close to the reference power level of the power transfer contract established during the negotiation phase and indicating a received power value received by the wireless power receiving device under a connected load condition. The connected load condition may indicate a situation where a load is connected to the wireless power receiving device.

[0203] The wireless power transmission device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet and responds ST2 with ACK or NAK in response to the second received power packet (RP / 2). More specifically, the wireless power transmission device determines whether the power level is stable at the second calibration data point based on the control error value. For example, when the control error value is less than 3, the wireless power transmission device can determine that the power level is stable and the wireless power receiving device has reached the desired target operating point; and respond with ACK in response to the second received power packet (RP / 2). When the control error value is greater than 3, the wireless power transmission device can determine that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and respond with NAK in response to the second received power packet (RP / 2).

[0204] The wireless power receiving device continues to send the second receive power packet (RP / 2) until it receives an ACK SR2 from the wireless power transmitting device. In addition, in order to stabilize the power level at the second calibration data point, the wireless power receiving device also repeatedly sends a control error packet to the wireless power transmitting device.

[0205] After the power level stabilizes at the second calibration data point and an ACK is received from the wireless power transmission device in response to the second received power packet (RP / 2) SR3, the wireless power reception device and the wireless power transmission device enter normal power transmission mode. The wireless power transmission device can construct a power calibration curve based on the first received power packet (RP / 1) and the second received power packet (RP / 2) in response to which the ACK was sent, and check for the occurrence of power loss due to foreign matter during power transmission based on the power calibration curve.

[0206] More specifically, the wireless power transmitting device can receive a received power packet (e.g., RP / 0) from the wireless power receiving device during power transmission, confirm the received power value received by the wireless power receiving device through the received power packet, and if the difference between the received power value calculated by applying the transmitted power value to the power calibration curve and the received power value confirmed by the ratio of the received power packet is greater than a threshold, it is assumed that power loss occurs due to foreign matter.

[0207] In the following, reference Figure 11, a power calibration curve according to the two-point power calibration method will be described.

[0208] The wireless power transmission device constructs a power calibration curve based on the first reception power packet (RP / 1) and the second reception power packet (RP / 2) in response to which ACK is transmitted.

[0209] Assume that the predicted value of the transmission power is obtained by P t(est) Indicates that the predicted value of the received power is obtained by P r(est) Indicates that the actual transmit power value is expressed by P t Indicated by P r Indicates that; if it is confirmed by foreign object detection (FOD) before power transmission (FOD before power) that there is no foreign object between the wireless power transmitting device and the wireless power receiving device, the following equation 1 is satisfied.

[0210] [Equation 1]

[0211] Pt(est)+δPt=Pt=Pr=Pr(est)-δPr

[0212] In Equation 1, δP t δP is the prediction error value of the transmission power and may include the power loss inherent in the wireless power transmission device. r is a prediction error value of the received power and may include power loss inherent to the wireless power receiving device.

[0213] Based on Equation 1, the calibrated power value P (cal) It can be calculated by the following equation 2.

[0214] [Equation 2]

[0215] P(cal)=δPt+δPr=Pr(est)-Pt(est)

[0216] Therefore, if RP / 1 (the first calibration data point) and RP / 2 (the second calibration data point) are inserted into Equation 2, the calibrated power values ​​can be expressed using Equation 3, respectively.

[0217] [Equation 3]

[0218] P1(cal)=RP / 1-Pt1(est)

[0219] P2(cal)=RP / 2-Pt2(est)

[0220] In other words, if it is confirmed from the pre-power FOD that no foreign matter exists, the relationship described by equations 1 to 3 is established, and the calibration curve based on equations 1 to 3 can be as follows Figure 11 Build as shown in .

[0221] The calibration protocol using two points (RP / 1 and RP / 2) cannot support the situation where the wireless power receiving device reaches the final load power through multiple steps. Therefore, a multi-point power calibration method is needed.

[0222] According to WPC Qi version 1.2.4, calibration information (RP / 1 and RP / 2) is only allowed to be transmitted once before starting power transfer; therefore, when the wireless power receiving device changes the operating point (e.g., target rectified voltage) during power transfer, the wireless power transmitting device cannot generate a new calibration curve during power transfer.

[0223] According to WPC Qi version 1.2.4, when power recalibration is required, the wireless power receiving device must reset the wireless power transmitting device by sending an EPT / rep packet and restart the wireless power transmission protocol from the beginning. This causes the wireless power receiving device to stop receiving power to recalibrate. Therefore, a multi-point power recalibration method is needed during power transmission.

[0224] In addition, when the wireless power receiving device sends the second receive power packet (RP / 2), the RP / 2 power level (second calibration data point) may be limited depending on the battery charge state. In particular, when the battery is almost fully charged, the difference between RP / 1 (first calibration data point) and RP / 2 (second calibration data point) becomes smaller, so that the power calibration range is limited. In addition, when high power transmission is required due to the operation of various applications causing the battery charge to decrease during power transmission, there is a problem that the calibration curve must be extrapolated because the calibration power itself is outside the range of the initial calibration curve. Therefore, in order to prevent extrapolation, a method is needed that can send additional calibration points to the wireless power transmitting device to extend the existing calibration curve while maintaining the operating point (e.g., target rectified voltage) during charging. In other words, a multi-point calibration method is needed to extend the calibration curve using multiple points.

[0225] Hereinafter, a multi-point power calibration method of an extended power calibration curve will be described.

[0226] Figure 12 is a flowchart illustrating a multi-point power calibration method according to one embodiment, Figure 13 FIGURE 1 illustrates the format of a received power packet according to one embodiment, Figure 14 is a state diagram illustrating a multi-point power calibration method using multiple RP / 2 according to one embodiment, Figure 15 is a graph illustrating a power calibration curve according to a multi-point power calibration method using multiple RP / 2 according to one embodiment, and Figure 16is a graph illustrating a power calibration curve according to a multi-point power calibration method using a plurality of RP / 2 according to another embodiment.

[0227] refer to Figure 12 According to the multi-point power calibration protocol of the extended power calibration curve, the wireless power receiving device sends a CE packet to the wireless power transmitting device S1101. Since the CE packet has been described above, its detailed description will be omitted.

[0228] refer to Figure 12 and Figure 14 The wireless power receiving device transmits a first receive power packet (RP / 1) including information about the first calibration data point to the wireless power transmitting device S1102, SR1. The CE packet and the first receive power packet (RP / 1) are transmitted after the negotiation phase, which may be transmitted at the beginning of the power transmission phase or before the power transmission phase.

[0229] refer to Figure 13 The first received power packet (RP / 1) includes a mode field and an estimated received power value field. The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the first received power packet (RP / 1) including information about the first calibration data point through the value of the mode field of the first received power packet (RP / 1), and confirm the first calibration data point through the value of the estimated received power value field of the first received power packet (RP / 1).

[0230] The first calibration data point is the starting point of the power calibration 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, and may be a received power value received by the wireless power receiving device under a light load condition. The light load condition may indicate a situation where a load (e.g., a battery) is not electrically connected to the wireless power receiving device.

[0231] The wireless power transmission device determines whether the wireless power reception device has reached the desired target operating point based on the control error value included in the CE packet, and responds with an ACK or NAK in response to the first received power packet (RP / 1) (ST1). More specifically, when the control error value is less than or equal to a predetermined level, the wireless power transmission device determines that the power level is stable and the wireless power reception device has reached the desired target operating point, and responds with an ACK in response to the first received power packet (RP / 1) (S1103). When the control error value is greater than or equal to the predetermined level, the wireless power transmission device determines that the power level is unstable and the wireless power reception device has not yet reached the desired target operating point; and may respond with a NAK in response to the first received power packet (RP / 1).

[0232] The wireless power receiving device continues to send the first receive power packet (RP / 1) until it receives an ACK from the wireless power transmitting device S1102. In addition, in order to stabilize the power level of the first calibration data point, the wireless power receiving device also repeatedly sends a control error packet to the wireless power transmitting device S1101.

[0233] After receiving ACK from the wireless power transmission device in response to the first reception power packet (RP / 1), the wireless power transmission device transmits a second reception power packet (RP / 2) including information about the second calibration data point to the wireless power transmission device S1105, SR2.

[0234] refer to Figure 13 The second receiving power packet (RP / 2) also includes a mode field and an estimated receiving power value field (see Figure 13 ). The wireless power transmitting device can confirm that the received power packet (RP) received from the wireless power receiving device is the second received power packet (RP / 2) including information about the second calibration data point by the value of the mode field of the second received power packet (RP / 2), and confirm the second calibration data point by the value of the estimated received power value field of the second received power packet (RP / 2). In order for the wireless power transmitting device to distinguish between the first calibration data point and the second calibration data point, the mode field of the first received power packet (RP / 1) and the mode field of the second received power packet (RP / 2) have different values. For example, the mode field of the first received power packet (RP / 1) may have a value of 1 ("001"b), and the mode field of the second received power packet (RP / 2) may have a value of 2 ("010"b).

[0235] The second calibration data point may be used to construct a power calibration curve corresponding to a power level close to a reference power level of the power transfer contract established during the negotiation phase and indicating a power value received by the wireless power receiving device under a connected load condition. The connected load condition may indicate a situation where a load is connected to the wireless power receiving device.

[0236] At the same time, the wireless power receiving device sends a CE packet to the wireless power transmitting device S1104. The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with ACK or NAK in response to the second received power packet (RP / 2) ST2. When the control error value is less than or equal to the predetermined level, the wireless power transmitting device determines that the power level is stable and the wireless power receiving device has reached the desired target operating point, and responds with ACK in response to the second received power packet (RP / 2) S1106. When the control error value is greater than or equal to the predetermined level, the wireless power transmitting device determines that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and may respond with NAK in response to the second received power packet (RP / 2).

[0237] The wireless power receiving device continues to send the second receive power packet (RP / 2) until it receives an ACK from the wireless power transmitting device (S1105). In addition, in order to stabilize the power level of the second calibration data point, the wireless power receiving device also repeatedly sends a control error packet S1104 to the wireless power transmitting device.

[0238] After receiving the ACK in response to the second receive power packet (RP / 2), the wireless power receiving device may determine whether it is necessary to send a continuous calibration data point. For example, the wireless power receiving device may check whether the desired target load power has been reached, or whether the operating point (e.g., V rec The wireless power receiving device can also determine whether a new calibration data point outside the range between the first and second calibration data points is required while checking the rectified voltage. In other words, when the target load power has not yet been reached, the wireless power receiving device can check whether a step-by-step increase to the target load power is required, and whether a new calibration data point outside the range between the first and second calibration data points is required, taking into account changes in the usage environment of the battery being charged.

[0239] When there is no need to transmit continuous calibration points, the wireless power receiving device may transmit a receive power packet (RP / 0 or RP / 4) whose mode field has a value different from the value of the mode field of the first receive power packet (RP / 1) and the second receive power packet (RP / 2), so that the power calibration protocol can be terminated and normal power transmission can resume SR3. The wireless power receiving device may transmit RP / 0 or RP / 4 to avoid calibration timeout, so that the power calibration protocol can be terminated. Reference Figure 13RP / 0 or RP / 4 may also have the same format as the first reception power packet (RP / 1) and the second reception power packet (RP / 2), and include an estimated reception power value indicating a normal value. Because RP / 0 or RP / 4 has a mode field whose value is different from the mode field value of the first reception power packet (RP / 1) and the second reception power packet (RP / 2), the wireless power transmission device can distinguish RP 0 or RP / 4 from RP / 1 and RP / 2.

[0240] When a continuous calibration point needs to be transmitted, the wireless power receiving device may again use the second receive power packet (RP / 2) to transmit a third calibration point (one of the continuous calibration points) to the wireless power transmitting device. In other words, the wireless power receiving device transmits a new second receive power packet (RP / 2) including information about the third calibration point to the wireless power transmitting device (S1108, SR3).

[0241] The third calibration data point is used to construct a power calibration curve and may be a power value higher than the second calibration data point to which the wireless power transmission apparatus responds with an ACK or a power value lower than the first calibration data point to which the wireless power transmission apparatus has responded with an ACK.

[0242] At the same time, the wireless power receiving device sends a CE packet to the wireless power transmitting device (S1107). The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with ACK or NACK in response to the new second received power packet (RP / 2) ST2. When the control error value is less than or equal to a preset level, the wireless power transmitting device determines that the power level is stable and the wireless power receiving device has reached the desired target operating point; and responds with ACK in response to the new second received power packet (RP / 2) S1109. When the control error value is greater than or equal to the predetermined level, the wireless power transmitting device determines that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and may respond with NAK in response to the new second received power packet (RP / 2).

[0243] The wireless power receiving device continues to send new second receive power packets (RP / 2) until it receives an ACK from the wireless power transmitting device S1108. In addition, in order to stabilize the power level at the third calibration data point, the wireless power receiving device also repeatedly sends control error packets to the wireless power transmitting device S1107.

[0244] refer to Figure 15The wireless power transmission device constructs a power calibration curve based on the calibration data points respectively included in the first reception power packet (RP / 1), the second reception power packet (RP / 2) and the new second reception power packet (RP / 2) in response to which ACK is sent.

[0245] When constructing a power calibration curve based on three calibration data points, a first power calibration curve A1 connecting the first calibration data point (Pt1, RP / 1) and the second calibration data point (Pt2, RP / 2) and a second power calibration curve A2 connecting the second calibration data point (Pt2, RP / 2) and the third calibration data point (Pt3, RP / 2) can be constructed.

[0246] The first power calibration curve A1 and the second power calibration curve A2 can be defined as first-order functions with different slopes and y-intercepts, and the wireless power transmitting device uses the received power value confirmed by using the received power group received from the wireless power receiving device, the transmitted power value, and the power calibration curve including the first power calibration curve A1 and the second power calibration curve A2 to perform foreign object detection S1110 due to the loss of transmission power.

[0247] At the same time, if necessary, the wireless power receiving device may transmit a fourth calibration data point to the wireless power transmitting device, causing the wireless power transmitting device to extend the power calibration curve. In this case, the wireless power receiving device may transmit the fourth calibration point, one of the consecutive calibration points, to the wireless power transmitting device by again using the second receive power packet (RP / 2).

[0248] The wireless power receiving device transmits a new second receive power packet (RP / 2) including information about the fourth calibration point to the wireless power transmitting device. The wireless power transmitting device then transmits an ACK or NAK based on the control error value included in the control error packet. Because the detailed description of this operation is similar to the description of transmitting the second receive power packet (RP / 2) including information about the third calibration point, a detailed description thereof will be omitted.

[0249] refer to Figure 16 , when constructing a power calibration curve based on the four calibration data points included in the received power group in response to which ACK is sent, the wireless power transmission device can construct a first power calibration curve A1 connecting the first calibration data point (Pt1, RP / 1) and the second calibration data point (Pt2, RP / 2), a second power calibration curve A2 connecting the second calibration data point (Pt2, RP / 2) and the third calibration data point (Pt3, RP / 2), and a third power calibration curve A3 connecting the third calibration data point (Pt3, RP / 2) and the fourth calibration data point (Pt4, RP / 2); and perform foreign object detection using the constructed power calibration curve.

[0250] In a similar manner, the wireless power receiving device and the wireless power transmitting device may construct a multi-point power calibration curve using one first reception power group (RP / 1) and a plurality of second reception power groups (RP / 2).

[0251] A calibration timeout can also be configured for the power calibration protocol. This is intended to prevent the insertion of foreign objects while the power calibration protocol is in progress.

[0252] The calibration timeout may include a calibration timeout (PRx calibration timeout) of the wireless power receiving device and a calibration timeout (PTx calibration timeout) of the wireless power transmitting device.

[0253] The calibration timeout of the wireless power receiving device refers to the time during which the wireless power receiving device performs power calibration. For example, it can be defined as the time required to send RP / 0 or RP / 4 after transmitting the first RP / 1. For example, the calibration timeout of the wireless power receiving device can be configured to 16 seconds.

[0254] The calibration timeout of the wireless power transmission device can be defined as the time required for the wireless power transmission device to send the first ACK in response to RP / 2 after receiving the first RP / 1. The calibration timeout of the wireless power transmission device can be less than the calibration timeout of the wireless power reception device, for example, it can be configured to 10 seconds.

[0255] Figure 17 is a state diagram illustrating a multi-point power calibration method using RP / 3 according to one embodiment, and Figure 18 is a graph illustrating a power calibration curve according to a multi-point power calibration method using RP / 3 according to one embodiment.

[0256] refer to Figure 17 , steps S1201 to S1206 of the multi-point power calibration protocol using the RP / 3 extended power calibration curve are the same as Figure 12 Therefore, detailed description thereof will be omitted.

[0257] However, with reference Figures 12 to 16 Unlike the described embodiment, when continuous calibration points need to be transmitted, the wireless power receiving device according to this embodiment sends the third calibration point as one of the continuous calibration points by using the third receiving power group (RP / 3) instead of the second receiving power group (RP / 2).

[0258] The third reception power packet (RP / 3) may have the same format as the first reception power packet (RP / 1) and the second reception power packet (RP / 2) (see Figure 13). However, the mode field of the third reception power group (RP / 3) may have a value different from the mode field values ​​of the first reception power group (RP / 1) and the second reception power group (RP / 2). For example, the mode field of the first reception power group (RP / 1) may have a value of 1 ("001"b), the mode field of the second reception power group (RP / 2) may have a value of 2 ("010"b), and the mode field of the third reception group (RP / 3) may have a value of 3 ("011"b).

[0259] In other words, after step S1206 , when it is necessary to transmit consecutive calibration points, the wireless power receiving device transmits a third reception power packet (RP / 3) including information about a third calibration point to the wireless power transmitting device S1208 .

[0260] At the same time, the wireless power receiving device transmits a CE packet to the wireless power transmitting device (S1207). The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with an ACK or NAK in response to the third received power packet (RP / 3). When the control error value is less than or equal to a preset level, the wireless power transmitting device determines that the power level is stable and the wireless power receiving device has reached the desired target operating point; and responds with an ACK in response to the third received power packet (RP / 3) (S1209). When the control error value is greater than or equal to the predetermined level, the wireless power transmitting device determines that the power level is unstable and the wireless power receiving device has not yet reached the desired target operating point; and may respond with a NAK in response to the third received power packet (RP / 3).

[0261] The wireless power receiving device continues to send the third received power packet (RP / 3) until it receives an ACK (S1208) from the wireless power transmitting device. In addition, in order to stabilize the power level of the third calibration data point, the wireless power receiving device also repeatedly sends a control error packet S1207 to the wireless power transmitting device.

[0262] refer to Figure 18 The wireless power transmission device constructs a power calibration curve based on the calibration data points respectively included in the first reception power packet (RP / 1), the second reception power packet (RP / 2) and the third reception power packet (RP / 3) in response to which ACK is sent.

[0263] When constructing a power calibration curve based on three calibration data points, the wireless power transmitting device can construct a first power calibration curve B1 connecting the first calibration data point (Ptl, RP / 1) and the second calibration data point (Pt2, RP / 2), and a second power calibration curve B2 connecting the second calibration data point (Pt2, RP / 2) and the third calibration data point (Pt3, RP / 3).

[0264] The first power calibration curve B1 and the second power calibration curve B2 can be defined as first-order functions with different slopes and y-intercepts, and the wireless power transmitting device uses the received power value confirmed by using the received power packet received from the wireless power receiving device, the transmitted power value, and the power calibration curve including the first power calibration curve B1 and the second power calibration curve B2 to perform foreign object detection due to transmission power loss, S1210.

[0265] As described above, because the power calibration curve can be extended, the calibration range is increased so that a wider range of power values ​​can be calibrated, and because calibration reliability is improved, the reliability of foreign matter detection based on power loss is also increased.

[0266] Hereinafter, a multi-point power calibration method for recalibrating a power calibration curve will be described.

[0267] Figure 19 is a flowchart illustrating a power recalibration method according to one embodiment, Figure 20 is a state diagram illustrating a power recalibration method according to one embodiment, and Figure 21 is a graph illustrating a power calibration curve according to a power recalibration method according to another embodiment.

[0268] The power recalibration protocol according to one embodiment can be distinguished by an initial calibration protocol and a subsequent calibration protocol. Figure 19 , the initial calibration protocol includes steps S1301 to S1306, and the subsequent calibration protocol includes steps S1310 to S1315.

[0269] Steps S1301 to S1306 of the initial calibration protocol are the same as Figure 12 Therefore, detailed description thereof will be omitted.

[0270] Although Figure 19 The initial calibration protocol shown in the uses a two-point calibration protocol to construct a power calibration curve based on two calibration data points. The initial calibration protocol can use a reference Figures 12 to 18 A multi-point calibration protocol is described for constructing a power calibration curve based on three or more calibration data points.

[0271] Assume that because there is no need to transmit consecutive calibration points after receiving an ACK in response to a second receive power packet (RP / 2) including information about a second calibration data point sent by the wireless power receiving device, RP / 0 or RP / 4 is sent to terminate the initial calibration protocol; in this case, the initial calibration protocol is performed using a two-point calibration protocol.

[0272] At the same time, when transmission of continuous calibration points is required after receiving an ACK in response to a second receive power packet (RP / 2) including information about a second calibration data point sent by the wireless power receiving device, thereby sending a second or third receive power packet including information about a third calibration data point, the initial calibration protocol is performed based on a multi-point calibration protocol.

[0273] If the initial calibration protocol is completed, the wireless power transmission device constructs a power calibration curve according to the initial calibration protocol and performs foreign object detection based on the power calibration curve S1307.

[0274] When it is determined that there is no foreign matter according to the result of the foreign matter detection, the power transmission phase is executed, and the wireless power transmission device transmits wireless power to the wireless power reception device S1308. For the convenience of description, Figure 19 The diagram shows a situation where the power transfer phase is performed after step S1307; however, the initial calibration protocol may be performed starting from the power transfer phase.

[0275] When the wireless power receiving device changes the target operating point (e.g., target rectified voltage) in the middle of wireless power transmission (S1309), a subsequent calibration protocol is performed, and the wireless power receiving device sends a new first received power packet (RP / 1) to the wireless power transmitting device, which includes information about the new first calibration data point (S1311, SR4→SR1). Figure 21 , for example, the wireless power receiving device may change the target operating point from a first operating point (5 V) to a second operating point (12 V).

[0276] The new first received power packet (RP / 1) also has the same format as the other received power packets. The new first received power packet (RP / 1) has the same mode field value as the first received power packet (RP / 1) sent in step S1302. However, because the new first received power packet (RP / 1) includes information about calibration data points that is different from the information included in the first received power packet (RP / 1) sent in step S1302, the value of the estimated received power value field may be different from the field of the first received power packet (RP / 1) sent in step S1302.

[0277] The wireless power transmission device can confirm that the received power packet (RP) received from the wireless power reception device is a new first received power packet (RP / 1) including information about the new first calibration data point through the value of the mode field of the new first received power packet (RP / 1), and can confirm the new first calibration data point through the value of the estimated received power value field of the new first received power packet (RP / 1). The new first calibration data point becomes the starting point of the power calibration curve updated through the recalibration protocol.

[0278] At the same time, the wireless power receiving device transmits a CE packet to the wireless power transmitting device (S1310). The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with an ACK or NAK in response to the new second receive power packet (RP / 2) (ST2). Since the detailed description related to the above has been given, it will be omitted.

[0279] The wireless power receiving device continues to transmit new first reception power packets (RP / 1) and control error packets S1310 , S1311 until it receives an ACK from the wireless power transmitting device S1312 .

[0280] After receiving ACK from the wireless power transmitting device in response to the new first receiving power packet (RP / 1), the wireless power receiving device sends a new second receiving power packet (RP / 2) including information about the new second calibration data point to the wireless power transmitting device S1314, SR2.

[0281] The new second received power packet (RP / 2) also has the same format as the other received power packets. The new second received power packet (RP / 2) has the same mode field value as the second received power packet (RP / 2) sent in step S1305. However, because the new second received power packet (RP / 2) includes information about calibration data points that is different from the information included in the second received power packet (RP / 2) sent in step S1305, the value of the estimated received power value field may be different from the value of the second received power packet (RP / 2) sent in step S1305.

[0282] The wireless power transmission device can confirm that the received power packet (RP) received from the wireless power reception device is a new second received power packet (RP / 2) including information about the new second calibration data point through the value of the mode field of the new second received power packet (RP / 2), and can confirm the new second calibration data point through the value of the estimated received power value field of the new second received power packet (RP / 2). The new second calibration data point constitutes a point for constructing the power calibration curve updated by the recalibration protocol.

[0283] At the same time, the wireless power receiving device transmits a CE packet to the wireless power transmitting device (S1313). The wireless power transmitting device determines whether the wireless power receiving device has reached the desired target operating point based on the control error value included in the CE packet, and responds with an ACK or NACK in response to the new second receive power packet (RP / 2) (ST2). Since the detailed description related to the above has been given, it will be omitted.

[0284] The wireless power receiving device continues to transmit new second reception power packets (RP / 2) and control error packets S1313, S1314 until it receives an ACK from the wireless power transmitting device, S1315.

[0285] After receiving an ACK in response to the new second receive power packet (RP / 2), the wireless power receiving device may determine whether it is necessary to send consecutive calibration data points.

[0286] When there is no need to transmit continuous calibration points, the wireless power receiving device can send a receive power packet (RP / 0 or RP / 4) whose mode field has a value different from that of the first receive power packet (RP / 1) and the second receive power packet (RP / 2), so that the power calibration protocol can be terminated and normal power transmission SR3 can be resumed.

[0287] The wireless power transmission device updates the power calibration curve based on the new first and second calibration points received through the subsequent calibration protocol, and performs foreign object detection using the updated power calibration curve ( S1316 ).

[0288] Although for ease of description Figure 19 The figure illustrates an example in which a subsequent calibration protocol is also performed based on the two-point calibration protocol. When the wireless power receiving device transmits a second or third receive power packet including information about a third calibration data point, because successive calibration points need to be transmitted after step S1315, the subsequent calibration protocol is performed based on the multi-point calibration protocol. In this case, the wireless power transmitting device uses the power calibration curve updated according to the multi-point calibration protocol to perform foreign object detection (S1316).

[0289] refer to Figure 21 , with the initial calibration protocol based on the reference Figure 12 The multi-point calibration protocol described above using one RP / 1 and multiple RP / 2 is performed at the first operating point (5V), and an initial calibration curve is constructed accordingly. Subsequently, the operating point is changed to the second operating point (12V), and as subsequent calibration protocols are also performed at the second operating point based on the multi-point calibration protocol using one RP / 1 and multiple RP / 2, the power calibration curve is updated accordingly.

[0290] According to the power recalibration method, when the wireless power receiving device changes an operating point (eg, a target rectified voltage) during power transmission, power recalibration may be performed without resetting the wireless power transmitting device.

[0291] Therefore, by resetting the wireless power transmission device, the charging time of the wireless power reception device can be prevented from being extended, and because the power calibration curve can be updated due to the change of the operating point, the reliability of foreign matter detection is also increased.

[0292] In the above, the multi-point power calibration method of extending the power calibration curve and the multi-point power calibration method of recalibrating the power calibration curve have been described. The power calibration method combining the multi-point power calibration method of extending the power calibration curve and the multi-point power calibration method of recalibrating the power calibration curve will be described below.

[0293] Figure 22 is a flow chart illustrating a power calibration method according to one embodiment.

[0294] refer to Figure 22 The wireless power transmitting device and the wireless power receiving device go through the ping phase ( S1401 ), the configuration phase ( S1402 ), and the negotiation phase ( S1403 ) and continue the calibration protocol. The wireless power receiving device transmits the first and second calibration data points to the wireless power transmitting device by sending a first receive power packet ( RP / 1 ) and a second receive power packet ( RP / 2 ) ( S1404 ).

[0295] The wireless power transmitting device constructs a calibration curve using the first calibration data point and the second calibration data point of the first reception power packet (RP / 1) and the second reception power packet (RP / 2) in response to which ACK is sent; transmits wireless power based on the calibration curve S1405; and performs foreign object detection.

[0296] Thereafter, as the wireless power receiving device changes the target operating point (eg, target rectified voltage), a multi-point power calibration method that extends the power calibration curve or a multi-point power calibration method that recalibrates (or updates) the power calibration curve is used for further progress.

[0297] If the wireless power receiving device does not change the target operating point (S1406) and needs to transmit consecutive calibration points, the multi-point power calibration method of the extended power calibration curve is used to further progress (S1407). As described above, the multi-point power calibration method of the extended power calibration curve transmits a third calibration data point to the wireless power transmitting device using a new second received power packet (RP / 2) or a third received power packet (RP / 3). The wireless power transmitting device constructs a power calibration curve using the first and second calibration data points received in step S1404 and the third calibration data point received in step S1407.

[0298] Meanwhile, when the wireless power receiving device changes the target operating point ( S1406 ), a multi-point power calibration method is used to recalibrate (or update) the power calibration curve. As described above, the multi-point power calibration method uses a new first receive power packet (RP / 1) and a new second receive power packet (RP / 2) to send new first and second calibration time points to the wireless power transmitting device. The wireless power transmitting device recalibrates (or updates) the power calibration curve using the newly received first and second calibration data points.

[0299] In other words, the wireless power receiving device and the wireless power transmitting device perform a calibration protocol that extends an existing power calibration curve or a calibration protocol that updates an existing power calibration curve depending on whether a target operating point is changed.

[0300] according to Figures 10 to 22 The wireless power transmission device of the embodiment corresponds to Figures 1 to 9 Therefore, the operation of the wireless power transmission device according to this embodiment is achieved by combining Figures 1 to 9 For example, the communication / control unit 120 may receive a data packet for detecting a foreign object by the wireless power transmission device, construct, expand, and / or update a power calibration curve, execute a foreign object detection method, transmit an ACK / NAK signal due to the result of foreign object detection, and the like.

[0301] In addition, according to Figures 10 to 22 The wireless power receiving device of the embodiment corresponds to Figures 1 to 9 Therefore, the operation of the wireless power receiving device according to this embodiment is achieved by combining Figures 1 to 9 For example, the communication / control unit 220 may transmit a data packet for detecting a foreign object by the wireless power receiving device, receive an ACK / NAK due to the result of the foreign object detection, and the like.

[0302] In the wireless power transmission method and apparatus or receiving method according to the embodiments of the present invention, since not all components or steps are required, the wireless power transmission method and apparatus or receiving method may be implemented by including some or all of the components or steps described above. In addition, the embodiments of the wireless power transmission method and apparatus or receiving method may be implemented in combination. In addition, the components or steps described above are not necessarily performed in the order described above, and the steps described later may be performed before the steps described earlier.

[0303] The foregoing description merely provides the technical concept of the present invention, and those skilled in the art may make various changes and modifications without departing from the essential features of the present invention. Therefore, the foregoing embodiments of the present invention may be implemented individually or in combination.

[0304] Therefore, the embodiments disclosed in the present invention are used to illustrate rather than limit the scope of the present invention, and the concept of the technical idea of ​​the present invention is not limited by these embodiments. The scope of protection of the present invention should be understood according to the following claims, and all technical ideas within the equivalent scope of the claims should be understood to fall within the scope of the present invention.

Claims

1. A wireless power transmitter for transmitting wireless power to a wireless power receiver, the wireless power transmitter being configured to: Initiate a digital ping to request a response; receiving the response from the wireless power receiver; After a negotiation phase, receiving a first receive power packet from the wireless power receiver, the first receive power packet including an estimated receive power value for a first calibration data point; sending an ACK in response to the first received power packet; receiving a second receive power packet from the wireless power receiver, the second receive power packet including an estimated receive power value for a second calibration data point; sending an ACK in response to the second received power packet; receiving a new second receive power packet from the wireless power receiver, the new second receive power packet including an estimated receive power value for a third calibration data point; sending an ACK in response to the new second received power packet; constructing a power calibration curve based on the first received power grouping, the second received power grouping, and the new second received power grouping, and performing foreign object detection based on the power calibration curve, wherein the ACK in response to the first reception power packet, the second reception power packet, or the new second reception power packet is transmitted when the power level is stabilized based on the control error packet including the control error value.

2. The wireless power transmitter according to claim 1, wherein The first reception power packet, the second reception power packet, and the new second reception power packet have the same packet structure including a mode field; and The mode field of the first reception power packet has a different value from the mode fields of the second reception power packet and the new second reception power packet.

3. The wireless power transmitter according to claim 1, wherein The mode field of the second reception power packet has the same value as the mode field of the new second reception power packet.

4. A wireless power receiver for receiving wireless power from a wireless power transmitter, the wireless power receiver being configured to: receiving a digital ping from the wireless power transmitter; sending a response associated with the digital ping to the wireless power transmitter; After the negotiation phase, sending a first receive power packet to the wireless power transmitter, the first receive power packet including an estimated receive power value for a first calibration data point; receiving an ACK in response to the first receive power packet from the wireless power transmitter; transmitting a second received power packet to the wireless power transmitter, the second received power packet including an estimated received power value for a second calibration data point; receiving an ACK in response to the second receive power packet from the wireless power transmitter; transmitting a new second received power packet to the wireless power transmitter, the new second received power packet including an estimated received power value for a third calibration data point; and receiving an ACK in response to the new second receive power packet from the wireless power transmitter, wherein the ACK is received in response to the first reception power packet, the second reception power packet, or the new second reception power packet when the power level is stabilized based on the control error packet including the control error value.

5. The wireless power receiver according to claim 4, wherein: The first reception power packet, the second reception power packet, and the new second reception power packet have the same packet structure including a mode field; and The mode field of the first reception power packet has a value different from values ​​of the mode fields of the second reception power packet and the new second reception power packet.

6. The wireless power receiver according to claim 4, wherein: The mode field of the second reception power packet has the same value as the mode field of the new second reception power packet.

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