Wireless power transmission device and operation method therefor

Abstract

The present disclosure relates to a wireless power transmission device and an operation method therefor, the method comprising the steps of: receiving first information from a wireless power reception device, the first information including information related to a transmission current and a mutual loss power of a transmission coil of a wireless power transmission device; receiving second information from the wireless power reception device, the second information including information related to a received current of a reception coil of the wireless power reception device, the phase difference between the received current and the transmission current, and / or a load resistance of the wireless power reception device; measuring a first transmission current of the transmission coil; calculating a first mutual loss power on the basis of the first information and the first transmission current; calculating a first loss power on the basis of the first mutual loss power and the second information, the first loss power being the loss power generated by the magnetic flux of the transmission coil, the magnetic flux of the reception coil, and a mutual magnetic flux connected between the transmission coil and the reception coil; measuring a second power loss between the wireless power transmission device and the wireless power reception device; and identifying a foreign object on the basis of the difference between the first loss power and the second loss power being greater than or equal to a reference value.

Description

Wireless power transmission device and its operating method

[0001] The present disclosure relates to a wireless power transmission device and an operating method thereof, according to one embodiment.

[0002] Wireless power transmission technology using magnetic induction is a method of transmitting power using an electromagnetic field induced in a coil. A wireless power transmission device generates an electromagnetic field by applying a current to a transmitting coil, and an induced electromotive force is formed in a receiving coil of a wireless power receiving device by the generated electromagnetic field, thereby allowing power to be transmitted wirelessly.

[0003] A wireless power receiver can perform in-band communication while wirelessly receiving power from a wireless power transmitter. The wireless power receiver can provide information to the wireless power transmitter by performing in-band communication. For example, the wireless power receiver can perform in-band communication based on an ASK (amplitude shift keying) modulation method. At least one additional element can be selectively connected to a resonant circuit of the wireless power receiver via a switch, and the wireless power receiver can perform modulation by controlling the on / off state of the switch. Depending on the modulation in the wireless power receiver, the amplitude of the current and / or voltage applied to the transmission coil of the wireless power transmitter can be changed. The wireless power transmitter can confirm the information provided by the wireless power receiver by demodulating and / or decoding information about the amplitude of the current and / or voltage applied to the transmission coil.

[0004] The presence of foreign objects can cause power loss from a wireless power transmitter to a wireless power receiver. Foreign object detection technology is required to improve power transfer efficiency.

[0005] According to one embodiment, a wireless power transmission device may include a transmitting coil, at least one controller including a processing circuit, and a memory storing instructions. The instructions, when executed by the at least one controller, may cause the wireless power transmission device to receive first information from a wireless power reception device. The first information may include information related to a transmission current and mutual loss power of the transmitting coil. The instructions, when executed by the at least one controller, may cause the wireless power transmission device to receive second information from the wireless power reception device. The second information may include information related to a reception current of a receiving coil of the wireless power reception device, a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power reception device. The instructions, when executed by the at least one controller, may cause the wireless power transmission device to measure a first transmission current of the transmitting coil. The instructions, when executed by at least one controller, may cause the wireless power transmission device to calculate a first mutual loss power based on the first information and the first transmission current. The instructions, when executed by at least one controller, may cause the wireless power transmission device to calculate a first loss power based on the first mutual loss power and the second information. The first loss power may be a loss power generated by a magnetic flux of the transmitting coil, a magnetic flux of the receiving coil, and / or a mutual magnetic flux connected between the transmitting coil and the receiving coil.The instructions, when executed by at least one controller, may cause the wireless power transmission device to measure a second power loss between the wireless power transmission device and the wireless power reception device. The instructions, when executed by at least one controller, may cause the wireless power transmission device to check for a foreign object based on a difference between the first power loss and the second power loss being greater than or equal to a reference value.

[0006] According to one embodiment, a method of operating a wireless power transmission device may include receiving first information from a wireless power reception device. The first information may include information related to a transmission current and mutual loss power of a transmission coil of the wireless power transmission device. The method may include receiving second information from the wireless power reception device. The second information may include information related to a reception current of a reception coil of the wireless power reception device, a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power reception device. The method may include measuring a first transmission current of the transmission coil. The method may include calculating a first mutual loss power based on the first information and the first transmission current. The method may include calculating a first loss power based on the first mutual loss power and the second information. The first loss power may be a loss power generated by the magnetic flux of the transmitting coil, the magnetic flux of the receiving coil, and the mutual magnetic flux connected between the transmitting coil and the receiving coil. The method may include an operation of measuring a second loss power between the wireless power transmitting device and the wireless power receiving device. The method may include an operation of checking for a foreign substance based on a difference between the first loss power and the second loss power being greater than or equal to a reference value.

[0007] According to one embodiment, a non-transitory computer-readable storage medium storing at least one instruction, wherein the at least one instruction, when executed by at least one controller including a processing circuit of a wireless power transmission device, causes the wireless power transmission device to perform at least one operation. The at least one operation may include receiving first information from a wireless power reception device. The first information may include information related to a transmission current and mutual loss power of a transmission coil of the wireless power transmission device. The at least one operation may include receiving second information from the wireless power reception device. The second information may include information related to a reception current of a reception coil of the wireless power reception device, a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power reception device. The at least one operation may include measuring a first transmission current of the transmission coil. The at least one operation may include calculating a first mutual loss power based on the first information and the first transmission current. The at least one operation may include calculating a first loss power based on the first mutual loss power and the second information. The first loss power may be a loss power generated by a magnetic flux of the transmitting coil, a magnetic flux of the receiving coil, and a mutual flux connected between the transmitting coil and the receiving coil. The at least one operation may include measuring a second loss power between the wireless power transmitting device and the wireless power receiving device. The at least one operation may include checking for a foreign substance based on a difference between the first loss power and the second loss power being equal to or greater than a reference value.

[0008] In one embodiment, a wireless power transmission device may include a transmitting coil, at least one controller including a processing circuit, and a memory storing instructions. The instructions, when executed by the at least one controller, may cause the wireless power transmission device to receive first information from a wireless power reception device. The first information may include information regarding an amount of power applied to the transmitting coil that is related to an amount of mutual loss power due to a friendly metal interfering with mutual magnetic flux. The mutual magnetic flux may include a magnetic flux coupled between a receiving coil of the wireless power reception device and the transmitting coil. The instructions, when executed by the at least one controller, may cause the wireless power transmission device to determine second information regarding a first transmission current applied to the transmitting coil while providing wireless charging power through the transmitting coil. The instructions, when executed by at least one controller, may cause the wireless power transmitter to determine third information regarding first power loss that occurred while the wireless power transmitter continuously provided wireless charging power to the wireless power receiver. The instructions, when executed by at least one controller, may cause the wireless power transmitter to detect a foreign metal object based on the first information, the second information, and the third information while the wireless power receiver provided wireless charging power through the transmitting coil.

[0009] The above and other aspects, features and advantages of specific embodiments of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.

[0010] FIG. 1A is a drawing illustrating a wireless power transmission system including a wireless power transmission device and a wireless power reception device according to one embodiment.

[0011] FIG. 1b is a drawing illustrating a wireless power transmission device and a wireless power reception device according to one embodiment.

[0012] FIG. 2A is a block diagram of a wireless power transmission device and a wireless power reception device according to one embodiment.

[0013] FIG. 2b is a diagram illustrating a circuit of a wireless power transmission device and a wireless power reception device according to one embodiment.

[0014] FIG. 3 is a diagram illustrating a phase of a wireless power transfer system according to one embodiment.

[0015] FIG. 4 is a flowchart of an operating method of a wireless power transmission device according to one embodiment.

[0016] FIG. 5 is a diagram illustrating misalignment of a wireless power transfer system according to one embodiment.

[0017] FIG. 6 is a diagram illustrating power loss according to one embodiment.

[0018] FIG. 7 is a diagram illustrating the relationship between phase difference and load resistance according to one embodiment.

[0019] FIG. 8 is a flowchart of a method of operating a wireless power transmission device in relation to the maximum resistance of a transmission resistor, according to one embodiment.

[0020] FIG. 9 is a flowchart of a method of operating a wireless power transmission device related to receiving resistance according to one embodiment.

[0021] FIG. 10 is a diagram illustrating the relationship between transmission resistance and reception resistance according to one embodiment.

[0022] FIG. 11 is a flowchart of a method of operating a wireless power transmission device related to inverter efficiency according to one embodiment.

[0023] FIG. 12 is a diagram illustrating inverter efficiency and rectifier efficiency according to one embodiment.

[0024] FIG. 13 is a diagram illustrating inverter efficiency and load resistance according to one embodiment.

[0025] FIG. 14 is a diagram illustrating mutual loss power and transmission current according to one embodiment.

[0026] FIG. 15 is a diagram illustrating mutual loss power and load resistance according to one embodiment.

[0027] FIG. 16 is a flowchart of an operating method of a wireless power transmission device and a wireless power reception device according to one embodiment.

[0028] FIG. 17 is a flowchart of an operating method of a wireless power transmission device and a wireless power reception device according to one embodiment.

[0029] FIG. 1A is a drawing illustrating a wireless power transmission system including a wireless power transmission device and a wireless power reception device according to one embodiment.

[0030] Referring to FIG. 1A, a wireless power transmission device (101) according to an embodiment can wirelessly transmit power (106) to a wireless power reception device (103). Wireless power transmission refers to technologies for transmitting power without a physical connection. For example, wireless charging technologies include an electromagnetic induction method using a coil, a resonance method using resonance, and a radio wave (RF / microwave radiation) method that converts electrical energy into microwaves and transmits it. The wireless power transmission device (101) can transmit power based on the induction method, the resonance method, or the radio wave radiation method. The wireless power transmission device (101) can be configured to perform wireless power transmission based on at least one transmission method among the induction method, the resonance method, and the radio wave radiation method. The wireless power transmission device (101) can also be configured to support all of the induction method, the resonance method, and the radio wave radiation method. Wireless power transmission standards can include Qi and PowerMat. Qi may include open technologies that enable wireless power transfer between electronic devices. PowerMat may include technologies that use magnetic induction. Standards that use magnetic resonance may include Rezence, Hiper, WiPower, etc. These methods can charge multiple devices simultaneously. For example, a wireless power transmission device (101) may transmit power (106) using an induction method. When the wireless power transmission device (101) uses an induction method, the wireless power transmission device (101) may include, for example, at least one of a power source, a DC-DC conversion circuit (e.g., a DC / DC converter), a DC-AC conversion circuit (e.g., an inverter), an amplifier circuit, an impedance matching circuit, at least one capacitor, at least one coil, or a communication modulation circuit.At least one capacitor may form a resonant circuit together with at least one coil. The wireless power transmission device (101) may include a coil that can generate an induced magnetic field when a current flows. The process of the wireless power transmission device (101) generating an induced magnetic field may be expressed as the wireless power transmission device (101) wirelessly transmitting power (106). In addition, in the coil of the wireless power reception device (103), an induced electromotive force (or current, voltage, and / or power) may be generated by a magnetic field generated in the surroundings according to an induction method. The process of generating an induced electromotive force through the coil may be expressed as the wireless power reception device (103) wirelessly receiving power (106).

[0031] According to one embodiment, a wireless power transmission device (101) can communicate with a wireless power reception device (103). The wireless power transmission device (101) can exchange information with the wireless power reception device (103). For example, the wireless power transmission device (101) can receive information (107) from the wireless power reception device (103). The wireless power transmission device (101) can provide information (107) to the wireless power reception device (103). For example, the wireless power transmission device (101) can communicate with the wireless power reception device (103) according to an in-band method. The wireless power transmission device (101) can modulate data to be transmitted according to, for example, a frequency shift keying (FSK) modulation method, and the wireless power reception device (103) can provide information (107) by modulating according to an amplitude shift keying (ASK) modulation method. The wireless power transmission device (101) can check the information (107) provided by the wireless power reception device (103) based on the amplitude of the current and / or voltage applied to the transmission coil. In FIG. 1A, the wireless power reception device (103) is illustrated as directly transmitting the information (107) to the wireless power transmission device (101), but this is only for easy understanding, and those skilled in the art will understand that the wireless power reception device (103) only controls the on / off of at least one switch inside. The operation of performing modulation based on the ASK modulation method and / or the FSK modulation method can be understood as an operation of transmitting data (or packet) according to the in-band communication method, and the operation of performing demodulation based on the ASK demodulation method and / or the FSK demodulation method can be understood as an operation of receiving data (or packet) according to the in-band communication method.

[0032] FIG. 1b is a schematic diagram of a wireless charging system according to one embodiment.

[0033] Referring to FIG. 1B, a wireless charging system according to an embodiment may include a wireless power transmission device (101) and a wireless power reception device (103). The wireless power transmission device (101) may be a charging pad that transmits wireless power based on power supplied from a charger (e.g., TA, travel adapter). According to an embodiment, the wireless power transmission device (101) is a device including a wireless power transmission function, and may be implemented as, for example, a smart phone, and there is no limitation on the form of implementation thereof. The wireless power reception device (103) may be an electronic device such as a smart phone or a wearable device, and there is no limitation on the form of implementation thereof. According to an embodiment, 101 is not limited to an embodiment of a device that transmits wireless power, and 101 may include a function of transmitting wireless power and a function of receiving wireless power. According to an embodiment, 103 is not limited to an embodiment of a device that receives wireless power, and 103 may include a function of receiving wireless power and a function of transmitting wireless power.

[0034] FIG. 2A is a block diagram of a wireless power transmission device and a wireless power reception device according to one embodiment.

[0035] Referring to FIG. 2A, according to one embodiment, a wireless power transmission device (101) may include a controller (215) (e.g., including a processing circuit). The wireless power transmission device (101) may include a memory (210). The wireless power reception device (103) may include a controller (250) (e.g., including a processing circuit). The wireless power reception device (103) may include a memory (220).

[0036] In this document, when the wireless power transmission device (101) or the wireless power reception device (103) performs a specific operation, it may mean that various hardware included in the wireless power transmission device (101) or the wireless power reception device (103), for example, a controller (e.g., 215 or 250) such as a controller (e.g., a micro controlling unit (MCU), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a microprocessor, or an application processor (AP)) performs a specific operation. When the wireless power transmission device (101) or the wireless power reception device (103) performs a specific operation, it may also mean that the controller (e.g., 215 or 250) controls other hardware to perform a specific operation. The wireless power transmission device (101) or the wireless power reception device (103) performing a specific operation may mean that at least one instruction for performing the specific operation stored in a storage circuit (e.g., memory (e.g., 210 or 220)) of the wireless power transmission device (101) or the wireless power reception device (103) is executed, thereby causing the controller (e.g., 215 or 250) or other hardware to perform the specific operation. The at least one instruction stored in the memory (e.g., 210 or 220) of the wireless power transmission device (101) or the wireless power reception device (103), when executed by the controller (e.g., 215 or 250), may cause the wireless power transmission device (101) or the wireless power reception device (103) to perform at least one operation. When the controller (e.g., 215 or 250) includes a processor, the processor may include various processing circuits and / or multiple processors.For example, the term "processor" as used herein, including in the claims, may encompass various processing circuits, including at least one processor, wherein one or more of the at least one processor may be configured to collectively perform the various functions described, individually and / or in a distributed manner. When the terms "processor," "at least one processor," and "one or more processors," as used herein, are described as being configured to perform a number of functions, these terms encompass, for example, without limitation, situations where one processor performs some of the recited functions and other processor(s) perform other of the recited functions, and also situations where a single processor can perform all of the recited functions. Furthermore, the at least one processor may comprise a combination of processors that perform the various recited / disclosed functions, for example, in a distributed manner. At least one processor may execute program instructions to achieve or perform the various functions.

[0037] Referring to FIG. 2A, according to one embodiment, a wireless power transmission device (101) may include at least one of a transmitting coil (213), an inverter (218), a converter (217), and / or a power source (211) (e.g., a power supply). A wireless power reception device (103) may include at least one of a receiving coil (221), a rectifier (255), a charger (244), and / or a battery (245).

[0038] Referring to FIG. 2b, an exemplary drawing of FIG. 2a will be described.

[0039] FIG. 2b is a diagram illustrating a circuit of a wireless power transmission device and a wireless power reception device according to one embodiment.

[0040] According to one embodiment, a wireless power transmission device (101) may include at least one of a power source (211), an inverter (218) including a plurality of switches (Q1, Q2, Q3, Q4), a capacitor (212), a transmitting coil (213), a demodulation circuit (214), a controller (215), and / or a DC / DC converter (217).

[0041] According to one embodiment, the power provided by the power source (211) may be provided to the DC / DC converter (217). The power source (211) may include at least one of an interface for connecting to an external travel adapter (TA), a battery (not shown), a charger (not shown), or a power management integrated circuit (PMIC) (not shown) of the wireless power transmission device (101). The power source (211) may provide, for example, direct current power to the DC / DC converter (217), but there is no limitation on the form of the power provided. The DC / DC converter (217) may convert the voltage of the provided power and provide it to the inverter (218). The DC / DC converter (217) may change the voltage of the input direct current power and convert the changed voltage (or driving voltage (V DD )) can be provided to the inverter (218). The DC / DC converter (217) can perform, for example, buck converting and / or boost converting, and can be implemented as, for example, a 3-level converter, but it will be understood by those skilled in the art that there is no limitation on the type thereof.

[0042] In one embodiment, the inverter (218) receives the driving voltage (V) provided from the DC / DC converter (217). DD) can be used to output AC power. A plurality of switches (Q1, Q2, Q3, Q4) can form, for example, a full bridge circuit, but there is no limitation on the number of switches or the type of bridge circuit. For example, when a full bridge circuit is formed, one end of the transmitting coil (213) can be connected to a connection point between the switches (Q1, Q2) via a capacitor (212), and the other end of the transmitting coil (213) can be connected to a connection point between the switches (Q3, Q4). The plurality of switches (Q1, Q2, Q3, Q4) can be controlled to be in an on state or an off state. For example, in order to generate AC power, the controller (215) can control the first switch (Q1) and the third switch (Q3) to be on during a first period while controlling the second switch (Q2) and the fourth switch (Q4) to be off, and can control the first switch (Q1) and the third switch (Q3) to be off during a second period while controlling the second switch (Q2) and the fourth switch (Q4) to be on, and can repeatedly perform the above-described control operations. The controller (215) can provide control signals (Q1_DRV, Q2_DRV, Q3_DRV, Q4_DRV) for generating the above-described AC power to the plurality of switches (Q1, Q2, Q3, Q4). Here, not only outputting the control signal, but also refraining from outputting the control signal can be referred to as control of the controller (215).For example, the controller (215) outputting a first control signal for generating AC power having a first frequency to the inverter (217) may mean that the controller (215) outputs a control signal (Q1_DRV, Q3_DRV) for controlling the switches (Q1, Q3) to be on for a period corresponding to the first frequency, and then outputs a control signal control signal (Q2_DRV, Q4_DRV) for controlling the switches (Q2, Q4) to be on for a period corresponding to the first frequency, and repeats the above-described output operations. Meanwhile, the controller (215) outputting a second control signal for generating AC power having a second frequency to the inverter (217) may mean that the controller (215) outputs a control signal control signal (Q1_DRV, Q3_DRV) for controlling the switches (Q1, Q3) to be in an on state for a period corresponding to the second frequency, and then outputs a control signal control signal (Q2_DRV, Q4_DRV) for controlling the switches (Q2, Q4) to be in an on state for a period corresponding to the second frequency, and repeats the above-described output operations. In this case, the period corresponding to the second frequency may be different from the period corresponding to the first frequency.

[0043] According to one embodiment, AC power generated by the inverter (218) may be applied to the transmitting coil (213). The capacitor (212) may form a resonant circuit with the transmitting coil (213). The transmitting coil (213) may form a magnetic field based on the applied AC power. A portion of the magnetic field (or magnetic flux) formed by the transmitting coil (213) may pass through a cross-section of the receiving coil (221) of the wireless power receiving device (103). As the magnetic field passing through the cross-section of the receiving coil (221) changes over time, an induced electromotive force (e.g., current, voltage, or power) may be generated in the receiving coil (221).

[0044] According to one embodiment, the demodulation circuit (214) demodulates a signal applied to the transmitting coil (213) (e.g., a voltage (219) applied to both ends of the transmitting coil (213)) to generate a demodulated signal (V demod ) can be output. The demodulation circuit (214) checks, for example, the signal amplitude or amplitude change amount applied to the transmitting coil (213) and outputs a demodulation signal (V demod ) can also be generated. The demodulation circuit (214) can generate a demodulation signal (V ) by, for example, down-converting the frequency of the AC power (e.g., 100 to 210 kHz). demod ) can be output. It may include a mixer and / or multiplier circuit to remove the carrier component (e.g., 100 to 210 kHz, which is the frequency of AC power) for wireless power transmission. Here, a waveform in which a component by modulation of the wireless power receiving device (103) and an AC power component by the wireless power transmitting device (101) are mixed may be applied to both ends of the coil (213) of the wireless power transmitting device (101), and accordingly, the frequency component of the AC power (e.g., 100 to 210 kHz) is named a carrier component, and those skilled in the art will understand that the wireless power receiving device (103) does not actually generate an electromagnetic wave in which modulated data is mixed with a carrier wave. Accordingly, the carrier component (e.g., 100 to 210 kHz, which is the frequency of AC power) can be removed from the voltage (219) at both ends of the transmitting coil (213). The demodulation circuit (214) additionally generates a demodulation signal (V demod ) can also be filtered (low-pass filtered) and output. The demodulation circuit (214) may include a low-pass filter. The demodulation circuit (214) filters the voltage (219) across the transmitting coil (213) and then down-converts the frequency of the AC power (e.g., 100 to 210 kHz), thereby generating a demodulated signal (V demod) can also be generated. The amplitude of the voltage (219) across the transmitting coil (213) can be changed according to the ASK modulation of the wireless power receiving device (103). According to one embodiment, the controller (215) outputs a demodulation signal (V) output by the demodulation circuit (214). demod ) can be used to check the information provided by the wireless power receiving device (103). The controller (215) may, for example, receive a demodulation signal (V demod ) can perform ADC (analog-to-digital converting). The controller (215) can decode the digital value obtained as the ADC result, and check the information provided by the wireless power receiving device (103) according to the decoding result. The decoding method may be, for example, based on the Qi standard, but it will be understood by those skilled in the art that there is no limitation thereto. Meanwhile, in the above-described embodiment, the demodulation circuit (214) has been described as performing frequency down-conversion (e.g., carrier elimination) and / or low-pass filtering, and the controller (215) performs ADC and / or decoding, but this is merely exemplary. According to one embodiment, the demodulation circuit (214) may be implemented to further perform at least one of ADC and decoding, and according to one embodiment, the controller (215) may be implemented to further perform frequency down-conversion (e.g., carrier elimination) and / or low-pass filtering. It will be understood by those skilled in the art that

[0045] According to one embodiment, the wireless power receiver (103) may include at least one of a receiving coil (221), a capacitor (222), a capacitor (223), a rectifier (255), a controller (250), a plurality of capacitors (261, 262, 263, 264), a plurality of switches (231, 232, 233, 234), a capacitor (241), a regulator (242), a capacitor (243), and / or a charger (244). For example, the wireless power receiver (103) may include a modulation circuit and / or a demodulation circuit. For example, the wireless power receiver (103) may perform modulation based on an ASK scheme by using a modulation circuit (e.g., a plurality of capacitors (261, 262, 263, 264), a plurality of switches (231, 232, 233, 234)). For example, the wireless power receiving device (103) can perform demodulation based on the FSK demodulation method using a demodulation circuit.

[0046] According to one embodiment, the receiving coil (221), the capacitor (222), and the capacitor (223) may form a resonant circuit. One end of the capacitor (222) may be connected to the receiving coil (221), and the other end of the capacitor (222) may be connected to one end of the capacitor (223) and one end of the rectifier (255). One end of the capacitor (223) may be connected to the other end of the capacitor (222), and the other end of the capacitor (223) may be connected to the other end of the receiving coil (221). For example, the capacitor (223) may be connected in parallel to a circuit formed by connecting the receiving coil (221) and the capacitor (222) in series. The other end of the capacitor (223) may be connected to the other end of the rectifier (255).

[0047] According to one embodiment, the rectifier (255) may include a plurality of switches (S1, S2, S3, S4) forming a full bridge circuit. One end of the resonant circuit may be connected to a connection point between the switches (S1, S2), and the other end of the resonant circuit may be connected to a connection point between the switches (S3, S4). The rectifier (255) may convert AC power received through the receiving coil (221) into DC power. The controller (250) may control the on / off states of the plurality of switches (S1, S2, S3, S4) so ​​that the AC power may be converted into DC power.

[0048] According to one embodiment, a capacitor (241) and a regulator (242) may be connected to the rectifier (255). One end of the capacitor (241) may be grounded. The regulator (242) may perform voltage conversion (e.g., buck converting and / or boost converting) and / or regulating of the rectified power output from the power conversion circuit.

[0049] According to one embodiment, the charger (244) can charge a battery (e.g., 245 of FIG. 2A) using power converted and / or regulated by the regulator (242). According to one embodiment, the charger (244) can control the voltage and / or current for charging the battery depending on the charging mode of the battery (e.g., constant current (CC) mode, constant voltage (CV) mode, or rapid charge mode). Depending on the implementation, a PMIC (not shown) may be connected to the regulator (242) instead of the charger (244).

[0050] According to one embodiment, the controller (250) may perform modulation in response to information to be provided by using a modulation circuit (e.g., a plurality of capacitors (261, 262, 263, 264), a plurality of switches (231, 232, 233, 234)). The controller (250) may determine a capacitor among the plurality of capacitors (261, 262, 263, 264) to perform modulation. Depending on the capacitor to perform modulation, the difference in amplitude of the voltage (219) sensed by the wireless power transmission device (101) may change. For example, when modulation is performed using only one capacitor (261), it is assumed that the difference in amplitude of the voltage (219) sensed by the wireless power transmission device (101) (e.g., the difference between the maximum amplitude of the voltage (219) while the switch (231) is on and the maximum amplitude of the voltage (219) while the switch (231) is off) is the first value. In this case, since the capacitors (262, 263, 264) are not used for modulation, the switches (232, 233, 234) can be maintained in the off state. Meanwhile, when modulation is performed with capacitors (261) and (262), the difference in amplitude of the voltage (219) sensed by the wireless power transmission device (101) (for example, the difference between the maximum amplitude of the voltage (219) while the switches (231, 232) are on and the maximum amplitude of the voltage (219) while the switches (231, 232) are off) may be a second value, which is greater than the first value. In this case, since the capacitors (263, 264) are not used for modulation, the switches (233, 234) may be maintained in the off state. The wireless power reception device (103) may adjust the modulation degree (or modulation depth) by adjusting a capacitor among the plurality of capacitors (261, 262, 263, 264) that performs modulation.As described above, the controller (250) may output and / or refrain from outputting at least some of the control signals (CMA1, CMA2, CMB1, CMB2) so that the switches corresponding to the non-determined capacitors remain in an off state while performing modulation using the determined capacitors. For example, the capacitance of the capacitor (262) may be smaller than the capacitance of the capacitor (261), and the capacitance of the capacitor (264) may be smaller than the capacitance of the capacitor (263), but this is merely an example and there is no limitation on the size of the capacitances, and they may be the same.

[0051] As described above, a difference in the amplitude of the voltage (219) at the transmitting coil (213) may occur depending on the modulation in the wireless power receiving device (103) (e.g., a difference between the maximum amplitude while at least one switch in the wireless power receiving device (103) is in the on state and the maximum amplitude while it is in the off state). Due to the difference in the amplitude of the voltage (219) at the transmitting coil (213) depending on the modulation, a change in the voltage applied to the capacitor included in the wireless power transmitting device (101) may be caused. For example, a constant value of voltage should preferably be applied to a capacitor to which a DC voltage is applied, but the voltage applied to the capacitor may also change depending on the modulation of the wireless power receiving device (103).

[0052] FIG. 3 is a diagram illustrating a phase of a wireless power transfer system according to one embodiment.

[0053] Referring to FIG. 3, the phases of the wireless power transfer system may include at least one of a selection phase of 300, a ping phase of 310, an identification phase and configuration phase of 320, a negotiation phase of 330, and / or a power transmission phase of 340. The phases of the wireless power transfer system may follow the Qi standard, for example, but are not limited thereto.

[0054] A wireless power transmission device (101) according to one embodiment may perform an operation corresponding to at least one of the steps of FIG. 3. A wireless power transmission device (101) according to one embodiment may not perform an operation corresponding to at least one of the steps of FIG. 3.

[0055] According to one embodiment, in the selection step (300), the wireless power transmission device (101) can monitor whether an object (e.g., the wireless power reception device (103) or a foreign substance) exists. For example, the wireless power transmission device (101) can detect the object (e.g., the wireless power reception device (103) or a foreign substance) based on application of a ping signal. The wireless power transmission device (101) can transition to the ping step (310) based on detection of the object (e.g., the wireless power reception device (103) or a foreign substance). In the ping step (310), the wireless power transmission device (101) can determine whether the detected object (e.g., the wireless power reception device (103) or a foreign substance) is a receiver (e.g., the wireless power reception device (103)). For example, the wireless power transmission device (101) can apply a digital ping signal to the transmission coil (213). The wireless power transmission device (101) can confirm that the detected object is a receiver (e.g., the wireless power reception device (103)) based on reception of a response corresponding to the digital ping signal. The wireless power transmission device (101) can perform at least one operation corresponding to the identification step and the configuration step (320) with the wireless power reception device (103), and the operation can follow the Qi standard, for example, but is not limited thereto. For example, the wireless power transmission device (101) can receive an identification packet and / or a configuration packet from the wireless power reception device (103). For example, the identification packet can include information about the version of the standard (e.g., the WPC (Wireless Power Consortium) version) and / or the unique code of the terminal manufacturer. For example, a configuration packet may include information about the power class and / or the required power.The wireless power transmission device (101) can check information about the terminal manufacturer, the standard version, and / or the maximum reception power based on the identification packet and / or the configuration packet. As described above, the wireless power transmission device (101) and the wireless power reception device (103) can perform in-band communication. If the wireless power transmission device (101) fails to acquire data from the wireless power reception device (103) during the digital ping signal application (for example, fails to confirm valid data as a demodulation result), the wireless power transmission device (101) may determine that a foreign substance is placed. If the operations in the identification step and the configuration step (320) are successfully completed, the wireless power transmission device (101) can perform at least one operation corresponding to the negotiation step (330), and the operation may follow the Qi standard, for example, but is not limited thereto. In the negotiation step (330), the wireless power transmission device (101) can exchange information (e.g., parameters) for power transmission with the wireless power reception device (103). After the negotiation step (330), the wireless power transmission device (101) can enter the power transmission step (340) and apply power for charging. In the power transmission step (340), the wireless power transmission device (101) can control the power transmission based on information (e.g., parameters) received from the wireless power reception device (103).

[0056] The operations of the wireless power transmission device (101) can be described in detail with reference to the embodiments described above (e.g., the embodiments of FIGS. 1A, 1B, 2A, 2B, and 3) and the embodiments described below (e.g., the embodiments of FIGS. 4 to 17). Although each embodiment is disclosed in a separate drawing and a separate paragraph, this is only for the convenience of explanation, and at least some of the embodiments described above and at least some of the embodiments described below can be applied together. At least some of the embodiments described above and at least some of the embodiments described below may be omitted.

[0057] With reference to the embodiments described below (e.g., the embodiments of FIGS. 4 to 17), the loss power of the wireless power transmission device (101) and the identification of foreign substances based on the loss power will be described.

[0058] FIG. 4 is a flowchart illustrating a method of operating a wireless power transmission device according to one embodiment. FIG. 5 is a diagram illustrating misalignment of a wireless power transmission system according to one embodiment. FIG. 6 is a diagram illustrating power loss according to one embodiment.

[0059] With reference to FIGS. 4, 5, and 6, mutual power loss and total power loss can be described. FIG. 5 is a cross-sectional view of a wireless power transmission device (101) and a wireless power reception device (103). In FIG. 5, the wireless power transmission device (101) may include a ferrite (510), a friendly metal (511), and a transmission coil (213). The friendly metal (511) is a metal included in the wireless power transmission device (101), and there is no limitation on the position where the friendly metal (511) is arranged. In FIG. 5, the wireless power reception device (103) may include a reception coil (221), a ferrite (520), and a friendly metal (521). The friendly metal (521) is a metal included in the wireless power receiving device (103), and there is no limitation on the position where the friendly metal (521) is placed. Hereinafter, the friendly metal (e.g., 511, 521, 213, 221 of FIG. 5) may be a concept including the friendly metal (511) of the wireless power transmitting device (101), the friendly metal (521) of the wireless power receiving device (103), the transmitting coil (213), and / or the receiving coil (221). FIG. 5 illustrates a case where a foreign substance (599) exists on the wireless power receiving device (103). In FIG. 5, even if misalignment occurs between the wireless power transmission device (101) and the wireless power reception device (103), a mutual magnetic flux (530) connected between the transmitting coil (213) of the wireless power transmission device (101) and the receiving coil (221) of the wireless power reception device (103) can be formed along the center of the receiving coil (221). For example, the mutual magnetic flux (530) can be a magnetic flux generated by the transmitting coil (213) that is linked to the receiving coil (221) to induce a voltage.For example, when two coils (e.g., a transmitting coil (213) and a receiving coil (221)) share the same magnetic field, the shared magnetic field (e.g., mutual flux (530)) can act as a medium for transmitting information. FIG. 6 is a graph of the transmitting current and loss power (e.g., the total loss power in FIG. 6 (a) and the mutual loss power in FIG. 6 (b)) of the transmitting coil (213) of the wireless power transmitting device (101). In FIG. 6, “r” may be a value corresponding to the misalignment of the wireless power transmitting device (101) and the wireless power receiving device (103) (e.g., the distance [mm] corresponding to the misalignment). The transmitting current may be a current flowing in the transmitting coil (213). The total loss power may include loss power generated in a friendly metal (e.g., 511, 521, 213, and / or 221 of FIG. 5) and / or a foreign substance (599) due to the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and the mutual flux (e.g., 530 of FIG. 5) connected between the transmitting coil (213) and the receiving coil (221). The mutual loss power may include loss power generated in a friendly metal (e.g., 511, 521, 213, and / or 221 of FIG. 5) and / or a foreign substance (599) due to the mutual flux (e.g., 530 of FIG. 5) connected between the transmitting coil (213) and the receiving coil (221). The total loss power (e.g., P. FM ) is the mutual loss power (e.g. P FM_M ), TX loss power (e.g. P FM_Tx ), and RX loss power (e.g. P FM_Rx ) can be the sum of (e.g., mathematical expression 1).

[0060] (Equation 1)

[0061] The mutual loss power is the mutual current (e.g. I M ) can be proportional to the square of (e.g., mathematical expression 2).

[0062] (Equation 2)

[0063] In mathematical expression 2, R FM_M may be mutual resistance. The mutual resistance may be a resistance corresponding to the mutual magnetic flux (e.g., 530 in FIG. 5) connected between the transmitting coil (213) and the receiving coil (221) in the T-shaped equivalent circuit of the loss power. The mutual resistance may be calculated by mathematical expression 2 based on the mutual loss power and the mutual current.

[0064] The mutual current may be the sum (e.g., vector sum) of the transmitting current and the receiving current. The transmitting current may be the current flowing in the transmitting coil (213). The receiving current may be the current flowing in the receiving coil (221). For example, the mutual current (e.g., I M ), transmitting current (e.g. I tx ), and receiving current (e.g. I rx ) can satisfy mathematical expression 3.

[0065] (Equation 3)

[0066] In mathematical expression 3, φ can be the phase difference between the transmission current and the reception current.

[0067] Referring to FIGS. 5 and 6, even if misalignment occurs between the wireless power transmission device (101) and the wireless power reception device (103), the change in reluctance (e.g., magnetic resistance) of the magnetic flux path that determines the size of the mutual magnetic flux (530) may be smaller than the total magnetic flux generated by the transmission coil (213). Accordingly, the mutual loss power (e.g., P FM_M ) is the transmission current of the transmission coil (213) (e.g., I tx ) can have linearity with respect to the square of (e.g., Equation 4).

[0068] (Equation 4)

[0069] TX loss power of mathematical expression 1 (e.g. P FM_Tx ) is, in the T-type equivalent circuit of the loss power, the transmission current (e.g. I tx ) may be the power loss due to TX power loss (e.g. P FM_Tx ) expected value (e.g. P FM_Tx (est) ) can be calculated by mathematical expression 5.

[0070] (Equation 5)

[0071] In mathematical expression 5, R` tx may be a transmission resistance. The transmission resistance may be a resistance measured at the transmission coil (213) while a mutual magnetic flux (e.g., 530 of FIG. 5) is connected between the transmission coil (213) and the reception coil (221). The wireless power transmission device (101) may measure the transmission resistance (e.g., the resistance measured at the transmission coil (213)) while a mutual magnetic flux (e.g., 530 of FIG. 5) is connected between the transmission coil (213) and the reception coil (221). For example, the wireless power transmission device (101) may measure the transmission resistance in the ping phase (310). For example, the wireless power transmission device (101) may also measure the transmission resistance in a phase different from the ping phase (310) (e.g., 320, 330, or 340 of FIG. 3).

[0072] In mathematical equation 5, R FM_M (est) can be the mutual power loss calculated by mathematical expression 4.

[0073] In mathematical equation 5, R coil_rx may be the basic resistance of the transmitting coil (213). The basic resistance of the transmitting coil (213) may be a value confirmed by an LCR meter when no mutual magnetic flux (e.g., 530 in FIG. 5) is connected between the transmitting coil (213) and the receiving coil (221).

[0074] The RX loss power of mathematical expression 1 (e.g. P FM_Rx ) is, in the T-type equivalent circuit of the loss power, the receiving current (e.g. I rx ) may be the power loss due to the RX loss power (e.g. P FM_Rx ) expected value (e.g. P FM_Rx (est) ) can be calculated by mathematical formula 6.

[0075] (Equation 6)

[0076] In mathematical expression 6, R` rx (est) is the receiving resistance (e.g. R` rx ) may be the expected value of the receiving resistance (e.g. R` rx ) may be the resistance in the receiving coil (213) while the mutual magnetic flux (e.g., 530 in Fig. 5) is connected between the transmitting coil (213) and the receiving coil (221). For example, the receiving resistance (e.g., R`) rx ) is the transmission resistance (e.g. R` tx ) can be proportional to the transmission resistance (e.g., R`). The wireless power transmission device (101) tx ), based on the receiving resistance (e.g. R` rx (est) ) can be calculated (e.g., Equation 7). Equation 7 shows the transmission resistance (e.g., R` tx ) and receiving resistance (e.g. R` rx (est) ) can be a linear relationship.

[0077] (Equation 7)

[0078] In mathematical expression 6, R FM_M (est) can be the mutual power loss calculated by mathematical expression 4.

[0079] In mathematical expression 6, R coil_rxmay be the basic resistance of the receiving coil (221). The basic resistance of the receiving coil (221) may be a value confirmed by an LCR meter when no mutual magnetic flux (e.g., 530 in FIG. 5) is connected between the transmitting coil (213) and the receiving coil (221).

[0080] According to one embodiment, the wireless power transmission device (101) calculates mutual loss power based on the relationship between the transmission current and mutual loss power, calculates total loss power based on the calculated mutual loss power, and calculates the calculated total loss power (e.g., P FM (est) ) and the measured total power loss (e.g. P FM (meas) ) difference (e.g. P FM Error = P FM (meas) - P FM (est) ) can be used to detect foreign substances. This will be explained in detail.

[0081] At least some of the operations of FIG. 4 may be omitted. The order of the operations of FIG. 4 may be changed. Operations other than those of FIG. 4 may be performed before, during, or after the operations of FIG. 4.

[0082] Referring to FIG. 4, in operation 401, according to one embodiment, the wireless power transmission device (101) (e.g., the controller 215) may receive first information including information on mutual loss power related to a transmission current from the wireless power reception device (103). For example, the wireless power transmission device (101) may receive the first information according to an in-band communication method (e.g., via the transmission coil 213). For example, the wireless power transmission device (101) may receive the first information according to an out-band communication method (e.g., via a communication circuit). There is no limitation on the manner in which the wireless power transmission device (101) receives the first information. According to one embodiment, the wireless power transmission device (101) may receive the first information in a negotiation step (330) for transmitting power to the wireless power reception device (103). In one embodiment, the first information may include information regarding an amount of power applied to the transmitting coil (213) in relation to an amount of mutual loss power due to a friendly metal (e.g., 511, 521, 213, and / or 221 of FIG. 5) that interferes with the mutual magnetic flux. For example, with respect to the first information, “power applied to the transmitting coil (213)” may include one of a transmitting current applied to the transmitting coil (213), a transmitting power applied to the transmitting coil (213), an output power (or output current) of an inverter (218) electrically connected to the transmitting coil (213), an input power (or input current) of the inverter (218), or a power (or current) at any point of the wireless power transmission device (101). For example, the first information may include information about the slope and intercept of the linear relationship between the mutual loss power and the power applied to the transmitting coil (213).For example, the first information may include information about a matching table between values ​​corresponding to mutual loss power and values ​​corresponding to power applied to the transmission coil (213). According to one embodiment, the first information may include information related to transmission current and mutual loss power of the transmission coil (213). For example, information related to transmission current and mutual loss power (e.g., the first information) may be information about a linear relationship, information about a matching table, or information about a value of mutual loss power, which may be understood with reference to the embodiments of FIGS. 16 and 17. Specifically, the following is described.

[0083] In relation to operation 401, referring to the embodiment of FIG. 16 described below, information related to transmission current and mutual loss power (e.g., first information) may be information about a linear relationship between the mutual loss power and the transmission current. Referring to the embodiment of FIG. 16 described below, information related to transmission current and mutual loss power (e.g., first information) may be information about a matching table of the transmission current and mutual loss power. Referring to the embodiment of FIG. 17 described below, information related to transmission current and mutual loss power (e.g., first information) may be information about a value of the mutual loss power. In relation to operation 401, the embodiment of FIG. 16 will be described herein, and the embodiment of FIG. 17 will be described later. For example, in relation to operation 401, in the embodiment of FIG. 16, information about the mutual loss power related to the transmission current may include information about a linear relationship between the mutual loss power and the transmission current (e.g., information about the slope and intercept of the linear relationship). For example, the mutual loss power and the transmission current are expressed by the above-mentioned mathematical expression 4 (e.g., mutual loss power (e.g., P FM_M ) and the transmitting current (e.g. I tx ) can satisfy the linear relationship.

[0084] (Equation 4)

[0085] According to one embodiment, the slope and intercept of the linear relationship between the mutual loss power and the transmission current (e.g., Equation 4) can be determined based on the load resistance of the wireless power receiving device (103), which will be described later in FIG. 15.

[0086] In relation to operation 401, according to one embodiment, information related to transmission current and mutual loss power (e.g., information about a linear relationship, information about a matching table, or information about a value of mutual loss power) may be stored in the wireless power transmission device (101). In this case, the wireless power transmission device (101) may, instead of operation 401, utilize an identification packet (e.g., information about a terminal) received from the wireless power reception device (103). For example, based on the received identification packet, the wireless power transmission device (101) may identify, among the information stored in the wireless power transmission device (101), information related to transmission current and mutual loss power corresponding to the wireless power reception device (103) (e.g., information about a linear relationship, information about a matching table, or information about a value of mutual loss power). Accordingly, the wireless power transmission device (101) may also perform operation 407, which will be described later.

[0087] In operation 403, according to one embodiment, the wireless power transmission device (101) (e.g., the controller (215)) may receive second information including information related to a reception current, a phase difference, and a load resistance from the wireless power reception device (103). For example, the wireless power transmission device (101) may receive the second information according to an in-band communication method (e.g., via the transmission coil (213)). For example, the wireless power transmission device (101) may receive the second information according to an out-band communication method (e.g., via a communication circuit). There is no limitation on the manner in which the wireless power transmission device (101) receives the second information. According to one embodiment, the wireless power transmission device (101) may receive the second information during a power transmission step. According to one embodiment, the second information may be information about a received current (e.g., a current flowing in the receiving coil (221) of the wireless power receiving device (103), a phase difference (e.g., a phase difference between the received current of the receiving coil (221) and the transmitted current of the transmitting coil (213), and / or a load resistance of the wireless power receiving device (103) (e.g., a value of the received current, a value of the phase difference, and / or a value of the load resistance). According to one embodiment, the second information may include information about a received current (e.g., a current flowing in the receiving coil (221) of the wireless power receiving device (103), a phase difference (e.g., a phase difference between the received current of the receiving coil (221) and the transmitted current of the transmitting coil (213), and / or a load resistance of the wireless power receiving device (103). For example, the information about the received current may be information about the received current or information for calculating the received current. Information related to phase difference can be the phase difference value or information for calculating the phase difference. For example, information related to phase difference can be information about the linear relationship between phase difference and load resistance, but there are no limitations.For example, the wireless power transmission device (101) may, in the negotiation phase, receive information about a linear relationship between a phase difference and a load resistance (e.g., information about the slope and intercept of the linear relationship). For example, the information related to the phase difference may be information about a constant phase difference for each load resistance. For example, when the load resistance is within a specific range, the phase difference may be determined as a specific value corresponding to the specific range. The information related to the load resistance may be a value of the load resistance or information for calculating the load resistance. For example, the second information may include information about an input current of the charger (244) of the wireless power reception device (103) and an input voltage of the charger (244). The input current of the charger (244) may be an output current of the rectifier (255) of the wireless power reception device (103). The input voltage of the charger (244) may be the output voltage of the rectifier (255) of the wireless power receiving device (103). The root mean square (RMS) value of the receiving current of the receiving coil (221) may be a constant multiple of the input current of the charger (244). The load resistance of the wireless power receiving device (103) may be the ratio of the input voltage of the charger (244) to the input current of the charger (244).

[0088] In operation 405, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may measure a transmission current (e.g., a first transmission current) of the transmission coil (213). For example, the wireless power transmission device (101) may measure a transmission current (e.g., a first transmission current) of the transmission coil (213) while transmitting power to the wireless power reception device (103).

[0089] In operation 407, according to one embodiment, the wireless power transmission device (101) (e.g., the controller (215)) may calculate a first mutual loss power (e.g., an expected value of the mutual loss power) based on the first information of operation 401 (e.g., information on the mutual loss power related to the transmission current) and the first transmission current of operation 405. For example, in the embodiment of FIG. 16, the wireless power transmission device (101) may calculate the first mutual loss power (e.g., an expected value of the mutual loss power) based on information on a linear relationship (e.g., mathematical expression 4) between the mutual loss power and the transmission current (e.g., information on the slope and the intercept of the linear relationship). The embodiment of FIG. 17 will be described later.

[0090] In operation 409, according to one embodiment, the wireless power transmission device (101) (e.g., the controller (215)) may calculate a first loss power based on the first mutual loss power of operation 407 and the second information of operation 403 (e.g., information related to the reception current, the phase difference between the reception current and the transmission current, and the load resistance). The first loss power may be an expected value of the total loss power. For example, the wireless power transmission device (101) may calculate the first loss power (e.g., the expected value of the total loss power) based on Equations 1 to 7. For example, the wireless power transmission device (101) may calculate the reception current (e.g., I rx ), transmitting current (e.g. I tx ), and based on the phase difference (e.g., φ) of the receive current and transmit current, the mutual current (e.g., I M ) can be calculated (e.g., mathematical expression 3). The wireless power transmission device (101) can calculate the mutual current (e.g., I M ) and the first mutual loss power (e.g. P FM_M ), based on the mutual resistance (e.g. R FM_M ) can be calculated (e.g., mathematical expression 2). The wireless power transmission device (101) has a mutual resistance (e.g., R FM_M), the first loss power can be calculated (Mathematical expression 1, and Mathematical expressions 4 to 7).

[0091] In operation 411, according to one embodiment, the wireless power transmission device (101) (e.g., the controller (215)) may measure a second power loss between the wireless power transmission device (101) and the wireless power reception device (103). The second power loss may be a measurement value of the total power loss. For example, the wireless power transmission device (101) may measure the second power loss between the wireless power transmission device (101) and the wireless power reception device (103) based on information received from the wireless power reception device (103) while transmitting power to the wireless power reception device (103) (e.g., information related to the reception power of the wireless power reception device (103). For example, the wireless power transmission device (101) may measure a second loss power (e.g., a measured value of total loss power) between the wireless power transmission device (101) and the wireless power reception device (103) based on the power provided from the power source (211) of the wireless power transmission device (101) and the received power output from the rectifier (255) of the wireless power reception device (103) while transmitting power to the wireless power reception device (103). For example, the wireless power transmission device (101) may measure the difference between the transmitted power provided by the wireless power transmission device (101) and the received power received by the wireless power reception device (103) while transmitting power to the wireless power reception device (103). Here, “measuring” may mean calculating the difference between the value corresponding to the received power and the value corresponding to the transmitted power.

[0092] In operation 413, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) calculates the difference (e.g., P) between the first loss power (e.g., expected value of total loss power) of operation 409 and the second loss power (e.g., measured value of total loss power) of operation 411.FM Error = P FM (meas) - P FM (est) ) is greater than or equal to a reference value, a foreign substance (e.g., the presence of a foreign substance) can be detected. The wireless power transmission device (101) (e.g., the controller (215)) determines the difference (e.g., P) between the first loss power (e.g., the expected value of the total loss power) of operation 409 and the second loss power (e.g., the measured value of the total loss power) of operation 411. FM Error = P FM (meas) - P FM (est) ) is less than the reference value, it can be confirmed that there is no foreign substance.

[0093] FIG. 7 is a diagram illustrating the relationship between phase difference and load resistance according to one embodiment.

[0094] As described above, in one embodiment, when information on the value of the phase difference between the reception current and the transmission current is transmitted from the wireless power receiving device (103) to the wireless power transmitting device (101), the wireless power transmitting device (101) can calculate the first loss power (e.g., the expected value of the total loss power) of operation 409 using the value of the phase difference.

[0095] Referring to FIG. 7, according to one embodiment, when information on the relationship between the phase difference between the reception current and the transmission current and the load resistance is transmitted from the wireless power receiving device (103) to the wireless power transmitting device (101), the wireless power transmitting device (101) can check the phase difference based on the received information, and calculate the first loss power (e.g., the expected value of the total loss power) of the 409 operation based on the checked phase difference. For example, as shown in FIG. 7, the phase difference (e.g., φ) and the load resistance (e.g., R) L ) can satisfy mathematical expression 8.

[0096] (Equation 8)

[0097] According to one embodiment, the wireless power transmitter (101) receives a phase difference (e.g., φ) and a load resistance (e.g., R) from the wireless power receiver (103). L ) can receive information (e.g., information on slope and intercept) about the linear relationship (e.g., mathematical expression 8). For example, the wireless power transmission device (101) may receive information about the phase difference (e.g., φ) and the load resistance (e.g., R) in the negotiation step (330) for transmitting power to the wireless power reception device (103). L ) can receive information (e.g., information on slope and intercept) about the linear relationship (e.g., mathematical expression 8). The wireless power transmission device (101) checks the load resistance of the wireless power reception device (103) and receives the phase difference (e.g., φ) and the load resistance (e.g., R L ) based on information about the linear relationship (e.g., information about the slope and intercept) (e.g., Equation 8) and the load resistance, the phase difference can be calculated.

[0098] FIG. 8 is a flowchart of a method of operating a wireless power transmission device related to the maximum resistance of a transmission resistor, according to one embodiment. FIG. 9 is a flowchart of a method of operating a wireless power transmission device related to the reception resistor, according to one embodiment. FIG. 10 is a diagram illustrating the relationship between a transmission resistor and a reception resistor, according to one embodiment.

[0099] Referring to FIGS. 8, 9, and 10, a method for improving the discrimination of foreign matter detection based on an upper limit value of the transmission resistance (e.g., maximum resistance) is described.

[0100] At least some of the operations of FIG. 8 may be omitted. The order of the operations of FIG. 8 may be changed. Operations other than those of FIG. 8 may be performed before, during, or after the operations of FIG. 8.

[0101] Referring to FIG. 8, in operation 801, according to one embodiment, the wireless power transmission device (101) (e.g., the controller 215) may receive third information from the wireless power reception device (103). For example, the wireless power transmission device (101) may receive the third information according to an in-band communication method (e.g., via the transmission coil 213). For example, the wireless power transmission device (101) may receive the third information according to an out-band communication method (e.g., via a communication circuit). There is no limitation on the method by which the wireless power transmission device (101) receives the third information. According to one embodiment, the wireless power transmission device (101) may receive the third information in a negotiation step (330) for transmitting power to the wireless power reception device (103). For example, the third information may include information on a maximum resistance (e.g., an upper limit value) of a transmission resistance of the transmission coil (213). The maximum resistance (e.g., upper limit) of the transmission resistance of the transmission coil (213) may be the transmission resistance measured in a state in which there is no foreign matter. The “state in which there is no foreign matter” may be, for example, a state in which, in FIG. 5, no foreign matter (e.g., 599) exists and the wireless power receiving device (e.g., 103) and the wireless power transmitting device (e.g., 101) are aligned. For example, the maximum resistance of the transmission resistance may be the upper limit value of the transmission resistance used in calculating the total power loss in Equations 1 to 7. For example, the wireless power transmitting device (101) may use either the maximum resistance received in operation 801 (e.g., the transmission resistance measured in a state in which there is no foreign matter) or the transmission resistance measured in operation 803 to calculate the power loss. As described below, the wireless power transmission device (101) can calculate the power loss (e.g., operation 807 or operation 809) by comparing the maximum resistance received in operation 801 (e.g., transmission resistance measured in the absence of foreign matter) with the transmission resistance measured in operation 803 (e.g., operation 805).The wireless power transmission device (101) can check for the presence of a foreign substance by comparing the calculated loss power (e.g., operation 807 or operation 809) with the actually measured loss power (e.g., operation 411 of FIG. 4) (e.g., operation 413 of FIG. 4). This is specifically described as follows.

[0102] In operation 803, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may measure a transmission resistance (e.g., resistance measured at the transmission coil (213)) (e.g., first transmission resistance) while a mutual magnetic flux (e.g., 530 of FIG. 5) is connected between the transmission coil (213) and the reception coil (221).

[0103] In operation 805, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may compare the transmission resistance measured in operation 803 (e.g., first transmission resistance) with the maximum resistance (e.g., upper limit value) of operation 801.

[0104] In operation 807, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may calculate the first loss power (e.g., an expected value of total loss power) of operation 409 based on the maximum resistance of the transmission resistance (e.g., using the upper limit value of the transmission resistance) instead of the first transmission resistance, based on the first transmission resistance of operation 803 being greater than or equal to the maximum resistance (e.g., an upper limit value) of operation 801.

[0105] In operation 809, according to one embodiment, the wireless power transmission device (101) (e.g., the controller (215)) may calculate the first loss power (e.g., an expected value of the total loss power) of operation 409 based on the first transmission resistance of operation 803 (e.g., using a value corresponding to the first transmission resistance) based on the first transmission resistance of operation 803 being less than the maximum resistance (e.g., an upper limit value) of operation 801. In operation 807 and operation 809, referring to Equations 1, 5, and 6, by applying the maximum resistance (e.g., an upper limit value), when there is a foreign substance, P FM The error increases, and when there is no foreign matter, P FM Since the error is small, the criterion P is used to prevent and / or reduce foreign object detection errors (e.g., false positive FOD (foreign object detection)). FM The error can be increased further.

[0106] At least some of the operations of FIG. 9 may be omitted. The order of the operations of FIG. 9 may be changed. Operations other than those of FIG. 9 may be performed before, during, or after the operations of FIG. 9.

[0107] Referring to FIG. 9, in operation 901, according to one embodiment, the wireless power transmission device (101) (e.g., the controller 215) may receive fourth information including information on a reception resistance related to a transmission resistance from the wireless power reception device (103). For example, the wireless power transmission device (101) may receive the fourth information according to an in-band communication method (e.g., via the transmission coil 213). For example, the wireless power transmission device (101) may receive the fourth information according to an out-band communication method (e.g., via a communication circuit). There is no limitation on the manner in which the wireless power transmission device (101) receives the fourth information. According to one embodiment, the wireless power transmission device (101) may receive the fourth information in a negotiation step (330) for transmitting power to the wireless power reception device (103). For example, the fourth information may include information about the receiving resistance of the receiving coil (221) related to the transmitting resistance of the transmitting coil (213). For example, information about the receiving resistance related to the transmitting resistance may include the transmitting resistance (e.g., R`) tx ) and receiving resistance (e.g. R` rx ) may be information (e.g., information on the slope and intercept) about the linear relationship (e.g., Equation 7). For example, referring to FIG. 10 and Equation 7, the receiving resistance (e.g., R`) rx ) is the transmission resistance (e.g. R` tx ) can be proportional to. In Fig. 10, z can be the z-axis gap due to the shielding material. The larger the z-axis gap due to the shielding material, the larger R` tx Wow R` rx Since decreases linearly, the receiving resistance (e.g. R`) is obtained by a linear relationship (e.g. Equation 7) obtained by the average resistance value per z-axis gap. rx (est) ) can be calculated.

[0108] (Equation 7)

[0109] In operation 903, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may calculate the reception resistance (e.g., first reception resistance) of the reception coil (221). For example, the wireless power transmission device (101) may calculate the transmission resistance (e.g., R`) tx ) and based on mathematical equation 7, the receiving resistance (e.g. R`) rx ) expected value (e.g. R` rx (est) )(e.g. first receiving resistance) can be calculated.

[0110] In operation 905, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may compare the receiving resistance calculated in operation 903 (e.g., first receiving resistance) with the maximum resistance (e.g., upper limit value) of operation 801 of FIG. 8.

[0111] According to one embodiment, referring to FIG. 17, instead of operations 901 and 903, the wireless power transmission device (101) (e.g., the controller 215) may receive information on the reception resistance of the wireless power reception device (103) (e.g., information on the value of the reception resistance) from the wireless power reception device (103). For example, the wireless power reception device (103) may calculate the reception resistance of the wireless power reception device (103) and transmit the calculated value to the wireless power transmission device (101). In this case, in operation 905, the wireless power transmission device (101) (e.g., the controller 215) may compare the information on the value of the reception resistance received from the wireless power reception device (103) with the maximum resistance (e.g., the upper limit value) of operation 801 of FIG. 8.

[0112] In operation 907, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may calculate the first loss power (e.g., an expected value of total loss power) of operation 409 based on the maximum resistance (e.g., using the upper limit value) instead of the first receiving resistance, based on the first receiving resistance of operation 903 being greater than or equal to the maximum resistance (e.g., an upper limit value) of operation 801 of FIG. 8.

[0113] In operation 909, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) may calculate the first loss power (e.g., an expected value of the total loss power) of operation 409 based on the first receiving resistance of operation 903 (e.g., using a value corresponding to the first receiving resistance), based on the first receiving resistance of operation 903 being less than the maximum resistance (e.g., an upper limit value) of operation 801 of FIG. 8.

[0114] FIG. 11 is a flowchart illustrating a method of operating a wireless power transmission device related to inverter efficiency according to one embodiment. FIG. 12 is a diagram illustrating inverter efficiency and rectifier efficiency according to one embodiment. FIG. 13 is a diagram illustrating inverter efficiency and load resistance according to one embodiment.

[0115] Referring to FIGS. 11, 12, and 13, a method for improving the discrimination of foreign matter detection based on inverter efficiency and rectifier efficiency will be described.

[0116] At least some of the operations of FIG. 11 may be omitted. The order of the operations of FIG. 11 may be changed. Operations other than those of FIG. 11 may be performed before, during, or after the operations of FIG. 11.

[0117] Referring to FIG. 11, in operation 1101, according to one embodiment, the wireless power transmission device (101) (e.g., the controller (215)) may receive fifth information including information on inverter efficiency related to transmission current from the wireless power reception device (103). For example, the wireless power transmission device (101) may receive the fifth information according to an in-band communication method (e.g., via the transmission coil (213)). For example, the wireless power transmission device (101) may receive the fifth information according to an out-band communication method (e.g., via a communication circuit). There is no limitation on the manner in which the wireless power transmission device (101) receives the fifth information. According to one embodiment, the wireless power transmission device (101) may receive the fifth information in a negotiation step (330) for transmission of power to the wireless power reception device (103). For example, the fifth information may include information on the inverter efficiency of the wireless power transmission device (101) related to the transmission current. The inverter efficiency may be information on the conversion efficiency of the inverter (218) of the wireless power transmission device (101). For example, the information on the inverter efficiency related to the transmission current may include information on the transmission current (e.g., I tx ) and inverter efficiency (e.g. η inverter ) may be information about the linear relationship (e.g., information about the slope and intercept) (e.g., information about Equation 9).

[0118] (Equation 9)

[0119] Mathematical expression 9 can be understood with reference to Fig. 12 (a) and Fig. 13. Referring to Fig. 12 (a), depending on the load resistance, the transmission current (e.g., I tx ) squared and the inverter efficiency (e.g. η inverter ) for linear relationships (e.g., equation 9) (e.g., slope (S inv ) and intercept (η inv,DC) can be determined. For example, the wireless power receiving device (103) can determine the slope (S) of the linear relationship (e.g., mathematical expression 9) for each load resistance in the absence of foreign substances. inv ) and intercept (η inv,DC ) can store information about the load resistance. For example, the wireless power receiving device (103) checks the load resistance and, based on the load resistance, transmits the current (e.g., I tx ) squared and the inverter efficiency (e.g. η inverter ) for linear relationships (e.g., equation 9) (e.g., slope (S inv ) and intercept (η inv,DC ) can be used to determine information about the slope of equation 9. For example, the slope (S) of equation 9 inv ) can have a linear relationship with the load resistance, as shown in (a) of Fig. 13. For example, the intercept (η) of Equation 9 inv,DC ), as shown in (b) of Fig. 12, the fluctuation may be small despite the change in load resistance. For example, the intercept (η) of Equation 9 inv,DC ) can correspond to a constant (e.g., AVG of (b) of Fig. 13). The wireless power receiving device (103) checks the load resistance and transmits a current (e.g., I) determined based on the load resistance. tx ) and inverter efficiency (e.g. η inverter ) for linear relationships (e.g., equation 9) (e.g., slope (S inv ) and intercept (η inv,DC ) can be transmitted to the wireless power transmission device (101). The wireless power transmission device (101) can transmit information (e.g., transmission current (e.g., I)) determined based on the load resistance in the wireless power reception device (103). tx ) and inverter efficiency (e.g. η inverter ) slope of the linear relationship (S inv ) and intercept (η inv,DC) can receive information about the wireless power transmission device (101). According to one embodiment, in the negotiation step (330) for transmitting power to the wireless power reception device (103), the wireless power transmission device (101) transmits a transmission current (e.g., I) per load resistance. tx ) and inverter efficiency (e.g. η inverter ) slope of the linear relationship (S inv ) and intercept (η inv,DC ) can receive information about the transmission current (e.g., I tx ) and inverter efficiency (e.g. η inverter ) slope of the linear relationship (S inv ) is the slope of Equation 9 (S inv ) and the slope and intercept of the linear relationship between the load resistance and the load current (e.g., (a) of Fig. 13). For example, the transmission current (e.g., I tx ) and inverter efficiency (e.g. η inverter ) is the intercept (η) of the linear relationship inv,DC ) has little variation in load resistance, so the intercept (η) of Equation 9 inv,DC ) may be information about the average value (e.g., (b) of Fig. 13).

[0120] In relation to operation 1101, for example, the fifth information may include information on the rectifier efficiency of the wireless power transfer device (101) related to the transmission current. The rectifier efficiency may be information on the conversion efficiency of the rectifier (255) of the wireless power transfer device (101). The rectifier efficiency may have a small fluctuation despite the change in load resistance, as shown in (b) of FIG. 12. For example, the rectifier efficiency (e.g., η) rectifier ) can be used as an average value. The wireless power transmission device (101) has a rectifier efficiency (e.g., η rectifier ) can receive information about the wireless power receiving device (103) (e.g., information about the average value of the rectifier efficiency).

[0121] In operation 1103, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) can check the second loss power of operation 411 of FIG. 4 based on the fifth information of operation 1101. For example, the wireless power transmission device (101) can determine the inverter efficiency (e.g., η inverter ), the second loss power of operation 411 of Fig. 4 (e.g., P FM (meas) ) can be verified (e.g., mathematical expression 11). For example, the wireless power transmission device (101) can be verified by checking the rectifier efficiency (e.g., η rectifier ), the second loss power of operation 411 of Fig. 4 (e.g., P FM (meas) ) can be verified (e.g., mathematical expression 11).

[0122] (Equation 11)

[0123] In Equation 11, P IN Silver may be the power provided from the power source (211) of the wireless power transmission device (101) while power is transmitted to the wireless power reception device (103). In mathematical expression 11, P OUT Silver may be the reception power output from the rectifier (255) of the wireless power receiving device (103) while power is transmitted to the wireless power receiving device (103). R coil_rx , I tx , R coil_rx , and I rx has been mentioned above.

[0124] FIG. 14 is a diagram illustrating mutual loss power and transmission current according to one embodiment. FIG. 15 is a diagram illustrating mutual loss power and load resistance according to one embodiment.

[0125] With reference to FIGS. 14 and 15, the first information of operation 401 of FIG. 4 can be explained.

[0126] Referring to Fig. 14, the linear relationship between the mutual loss power and the transmission current (e.g., mathematical expression 4) can be determined according to the load resistance of the wireless power receiving device (103). Referring to Fig. 15, it is as follows.

[0127] Referring to FIG. 15, the slope and intercept of the linear relationship between the mutual loss power and the transmission current (e.g., Equation 4) may be determined based on the load resistance of the wireless power receiving device (103). For example, as the load resistance increases, the intercept of the linear relationship between the square of the transmission current and the mutual loss power may increase in FIG. 15. For example, as the load resistance increases, the slope of the linear relationship between the square of the transmission current and the mutual loss power may increase in FIG. 15. According to one embodiment, the wireless power receiving device (103) may check the load resistance and determine the slope and intercept of the linear relationship between the mutual loss power and the transmission current (e.g., Equation 4) based on the load resistance. The wireless power transmission device (101) may receive, from the wireless power reception device (103), information determined by the wireless power reception device (103) (e.g., information about the slope and intercept of the linear relationship between the mutual loss power and the transmission current determined based on the load resistance (e.g., mathematical expression 4)). According to one embodiment, the wireless power transmission device (101) may receive, in a negotiation step (330) for transmitting power to the wireless power reception device (103), information about the slope and intercept of the linear relationship between the square of the transmission current and the mutual loss power. For example, the information about the slope of the linear relationship between the square of the transmission current and the mutual loss power may be information about the slope and intercept of the linear relationship between the slope and the load resistance (e.g., (a) of FIG. 15). For example, information about the intercept of the linear relationship between the square of the transmission current and the mutual loss power may be information about the slope and intercept in the linear relationship between the intercept and the load resistance (e.g., (b) of Fig. 15).

[0128] Fig. 16 is a flowchart of an operating method of a wireless power transmission device and a wireless power reception device according to one embodiment. Fig. 17 is a flowchart of an operating method of a wireless power transmission device and a wireless power reception device according to one embodiment.

[0129] With reference to FIG. 16 and FIG. 17, information transmitted between a wireless power transmission device (101) and a wireless power reception device (103) can be described.

[0130] The embodiments of FIGS. 4 to 15 have been described based on the embodiment of FIG. 16. The embodiments of FIGS. 4 to 15 can also be applied to the embodiment of FIG. 17.

[0131] Fig. 16 may be an embodiment in which information about a linear relationship (e.g., information about a slope and an intercept) is transmitted from a wireless power receiving device (103) to a wireless power transmitting device (101). Fig. 16 may be an embodiment in which information about a matching table (e.g., information about a table in which independent and dependent variables are matched) is transmitted from a wireless power receiving device (103) to a wireless power transmitting device (101).

[0132] FIG. 17 may be an embodiment in which information on a linear relationship (e.g., information on a slope and an intercept) is used, information on an independent variable is transmitted from a wireless power transmission device (101) to a wireless power reception device (103), and information on a dependent variable is transmitted from a wireless power reception device (103) to a wireless power transmission device (101). FIG. 17 may be an embodiment in which information on a matching table (e.g., information on a table in which independent variables and dependent variables are matched) is used, information on an independent variable is transmitted from a wireless power transmission device (101) to a wireless power reception device (103), and information on a dependent variable is transmitted from a wireless power reception device (103) to a wireless power transmission device (101).

[0133] In FIG. 16 and FIG. 17, information about the linear relationship (e.g., information about the slope and intercept) may correspond to Equation 4, Equation 7, Equation 8, or Equation 9.

[0134] Mathematical expression 4 is the mutual loss power (e.g. P FM_M ) and the transmitting current (e.g. I tx ) can be a linear relationship.

[0135] Mathematical expression 7 is the transmission resistance (e.g. R`) tx ) and receiving resistance (e.g. R` rx (est) ) can be a linear relationship.

[0136] Mathematical expression 8 is a function of phase difference (e.g., φ) and load resistance (e.g., R L ) can be a linear relationship.

[0137] Mathematical expression 9 is the transmission current (e.g., I tx ) and inverter efficiency (e.g. η inverter ) can be a linear relationship.

[0138] In FIG. 16 and FIG. 17, information about the matching table (e.g., information about the table where independent variables and dependent variables are matched) may correspond to Equation 4, Equation 7, Equation 8, or Equation 9.

[0139] For example, with respect to Equation 4, in the information about the matching table (e.g., information about the table where the independent and dependent variables are matched), the independent variable is the transmission current (e.g., I tx ) and the dependent variable is the mutual loss power (e.g., P FM_M ) may be.

[0140] For example, with respect to Equation 7, in the information about the matching table (e.g., information about the table where the independent and dependent variables are matched), the independent variable is the transmission resistance (e.g., R`). tx ) and the dependent variable is the receiving resistance (e.g. R` rx (est) ) may be.

[0141] For example, with respect to Equation 8, in the information about the matching table (e.g., information about the table where the independent and dependent variables are matched), the independent variable is the load resistance (e.g., R L ), and the dependent variable may be a phase difference (e.g., φ).

[0142] For example, with respect to Equation 9, in the information about the matching table (e.g., information about the table where the independent and dependent variables are matched), the independent variable is the transmission current (e.g., I tx ) and the dependent variable is the inverter efficiency (e.g., η inverter ) may be.

[0143] Referring to Fig. 16, an example related to a linear relationship is described as follows.

[0144] Referring to FIG. 16, in operation 1601, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) may store information about a linear relationship (e.g., information about a slope and an intercept).

[0145] In operation 1603, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) may transmit information about a linear relationship (e.g., information about a slope and an intercept) to the wireless power transmitting device (101). The wireless power transmitting device (101) (e.g., controller (215)) may receive information about a linear relationship (e.g., information about a slope and an intercept) from the wireless power receiving device (103).

[0146] In operation 1605, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) is configured to control an independent variable (e.g., transmission current (e.g., I tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. R L )) can be confirmed.

[0147] In operation 1607, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) determines a dependent variable (e.g., mutual loss power (e.g., P) based on information about the linear relationship of operation 1603. FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can be calculated.

[0148] Referring to FIG. 16, an embodiment related to a matching table is described as follows.

[0149] Referring to FIG. 16, in operation 1601, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) may store information about a matching table (e.g., information about a table in which independent variables and dependent variables are matched).

[0150] In operation 1603, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) may transmit information about a matching table (e.g., information about a table where independent variables and dependent variables are matched) to the wireless power transmitting device (101). The wireless power transmitting device (101) (e.g., controller (215)) may receive information about a matching table (e.g., information about a table where independent variables and dependent variables are matched) from the wireless power receiving device (103).

[0151] In operation 1605, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) is configured to control an independent variable (e.g., transmission current (e.g., I tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. R L )) can be confirmed.

[0152] In operation 1607, according to one embodiment, the wireless power transmission device (101) (e.g., controller (215)) determines a dependent variable (e.g., mutual loss power (e.g., P)) based on information about the matching table of operation 1603. FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can be confirmed.

[0153] Referring to Figure 17, an example related to a linear relationship is described as follows.

[0154] Referring to FIG. 17, in operation 1701, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) may store information about a linear relationship (e.g., information about a slope and an intercept).

[0155] In operation 1703, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) is configured to control an independent variable (e.g., a transmission current (e.g., I tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. R L )) can receive information about the wireless power transmission device (101). The wireless power transmission device (101) (e.g., controller (215)) can receive information about the independent variable (e.g., transmission current (e.g., I tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. R L )) can be transmitted to the wireless power receiving device (103).

[0156] In operation 1705, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) provides information about the linear relationship of operation 1701, and the independent variable of operation 1703 (e.g., transmission current (e.g., I tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. RL )), the dependent variable (e.g., mutual loss power (e.g., P FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can be calculated.

[0157] In operation 1707, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) determines a dependent variable (e.g., mutual loss power (e.g., P FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can transmit information about the wireless power transmission device (101). The wireless power transmission device (101) (e.g., controller (215)) can transmit information about the dependent variable (e.g., mutual loss power (e.g., P FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can receive information from the wireless power receiving device (103).

[0158] Referring to Fig. 17, an embodiment related to a matching table is described as follows.

[0159] Referring to FIG. 17, in operation 1701, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) may store information about a matching table (e.g., information about a table in which independent variables and dependent variables are matched).

[0160] In operation 1703, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) is configured to control an independent variable (e.g., a transmission current (e.g., I tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. R L)) can receive information about the wireless power transmission device (101). The wireless power transmission device (101) (e.g., controller (215)) can receive information about the independent variable (e.g., transmission current (e.g., I tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. R L )) can be transmitted to the wireless power receiving device (103).

[0161] In operation 1705, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) receives information about the matching table of operation 1701, and an independent variable (e.g., transmission current (e.g., I)) of operation 1703. tx ), transmission resistance (e.g. R` tx ), and / or load resistance (e.g. R L )), the dependent variable (e.g., mutual loss power (e.g., P FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can be confirmed.

[0162] In operation 1707, according to one embodiment, the wireless power receiving device (103) (e.g., controller (250)) determines a dependent variable (e.g., mutual loss power (e.g., P FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can transmit information about the wireless power transmission device (101). The wireless power transmission device (101) (e.g., controller (215)) can transmit information about the dependent variable (e.g., mutual loss power (e.g., P FM_M ), receiving resistance (e.g. R` rx (est) ), phase difference (e.g., φ), and / or inverter efficiency (e.g., η inverter )) can receive information from the wireless power receiving device (103).

[0163] Those skilled in the art will appreciate that the embodiments described herein may be applied interchangeably, within the scope of their applicability. For example, those skilled in the art will appreciate that at least some operations of one embodiment described herein may be omitted and applied, or at least some operations of one embodiment may be applied in conjunction.

[0164] The technical tasks to be achieved in this document are not limited to the technical tasks mentioned above, and other technical tasks not mentioned will be clearly understood by those with ordinary skill in the technical field to which this document pertains from the description below.

[0165] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0166] According to one embodiment, a wireless power transmission device (101) may include a transmitting coil (213), at least one controller (215) including a processing circuit, and a memory (210) storing instructions. The instructions, when executed by the at least one controller (215), may cause the wireless power transmission device (101) to receive first information from the wireless power reception device (103). The first information may include information related to a transmission current and mutual loss power of the transmitting coil (213). The instructions, when executed by the at least one controller (215), may cause the wireless power transmission device (101) to receive second information from the wireless power reception device (103). The second information may include information related to a reception current of the reception coil (221) of the wireless power reception device (103), a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power reception device (103). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to measure a first transmission current of the transmission coil (213). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate a first mutual loss power based on the first information and the first transmission current. The above instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate a first loss power based on the first mutual loss power and the second information.The first loss power may be a loss power generated by a magnetic flux of the transmitting coil (213), a magnetic flux of the receiving coil (221), and / or a mutual magnetic flux connected between the transmitting coil (213) and the receiving coil (221). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to measure a second loss power between the wireless power transmission device (101) and the wireless power reception device (103). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to check for a foreign substance based on a difference between the first loss power and the second loss power being equal to or greater than a reference value.

[0167] According to one embodiment, in the wireless power transmission device (101), the first power loss may include power loss generated in the friendly metal by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and / or the mutual magnetic flux.

[0168] According to one embodiment, in the wireless power transmission device (101), the friendly metal may include the first friendly metal of the wireless power reception device (103), the second friendly metal of the wireless power transmission device, the transmission coil (213), and / or the reception coil (221).

[0169] According to one embodiment, in the wireless power transmission device (101), the first information may be received through the transmission coil (213). The second information may be received through the transmission coil (213).

[0170] According to one embodiment, in the wireless power transmission device (101), the instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to receive the first information in a negotiation step for power transmission to the wireless power reception device (103). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to receive the second information in a power transfer step to the wireless power reception device (103).

[0171] According to one embodiment, in the wireless power transmission device (101), the first information may include information on the slope and intercept of the linear relationship between the mutual loss power and the transmission current.

[0172] According to one embodiment, in the wireless power transmission device (101), the instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate a mutual current based on the received current, the transmitted current, and the phase difference between the received current and the transmitted current. The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate a mutual resistance based on the mutual current and the mutual loss power. The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate the first loss power based on the mutual resistance.

[0173] According to one embodiment, in the wireless power transmission device (101), the instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to receive third information from the wireless power reception device (103) via the transmission coil (213). The third information may include information about a maximum resistance of a transmission resistance of the transmission coil (213). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to measure a first transmission resistance of the transmission coil (213) while the mutual magnetic flux is coupled between the transmission coil (213) and the reception coil (221). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate the first loss power based on the maximum resistance, based on the first transmission resistance being greater than or equal to the maximum resistance. The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate the first loss power based on the first transmission resistance, based on the first transmission resistance being less than the maximum resistance.

[0174] According to one embodiment, in the wireless power transmission device (101), the instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to receive fourth information from the wireless power reception device (103) via the transmission coil (213). The fourth information may include information about a reception resistance of the reception coil (221) related to the transmission resistance of the transmission coil (213). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate a first reception resistance of the reception coil (221) based on the fourth information and the first transmission resistance. The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate the first loss power based on the maximum resistance, based on the first receiving resistance being greater than or equal to the maximum resistance. The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate the first loss power based on the first receiving resistance, based on the first receiving resistance being less than the maximum resistance.

[0175] According to one embodiment, in the wireless power transmission device (101), the instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to receive fifth information from the wireless power reception device (103) via the transmission coil (213). The fifth information may include information on inverter efficiency of the wireless power transmission device (101) related to the transmission current. The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to determine the second power loss based on the inverter efficiency.

[0176] According to one embodiment, in the wireless power transmission device (101), the fifth information may include information about the slope and intercept of the linear relationship between the inverter efficiency and the transmission current. The slope of the linear relationship between the inverter efficiency and the transmission current may be determined by the wireless power reception device (103) based on the load resistance of the wireless power reception device (103).

[0177] According to one embodiment, in the wireless power transmission device (101), the second information may include information about the input current of the charger of the wireless power reception device (103) and the input voltage of the charger.

[0178] According to one embodiment, in the wireless power transmission device (101), the slope of the linear relationship between the mutual loss power and the transmission current can be determined by the wireless power reception device (103) based on the load resistance of the wireless power reception device (103).

[0179] According to one embodiment, a method of operating a wireless power transmission device (101) may include an operation of receiving first information from a wireless power reception device (103). The first information may include information related to a transmission current and mutual loss power of a transmission coil (213) of the wireless power transmission device (101). The method may include an operation of receiving second information from the wireless power reception device (103). The second information may include information related to a reception current of a reception coil (221) of the wireless power reception device (103), a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power reception device (103). The method may include an operation of measuring a first transmission current of the transmission coil (213). The method may include an operation of calculating a first mutual loss power based on the first information and the first transmission current. The method may include an operation of calculating a first loss power based on the first mutual loss power and the second information. The first loss power may be a loss power generated by a magnetic flux of the transmitting coil (213), a magnetic flux of the receiving coil (221), and a mutual flux connected between the transmitting coil (213) and the receiving coil (221). The method may include an operation of measuring a second loss power between the wireless power transmitting device (101) and the wireless power receiving device (103). The method may include an operation of checking for a foreign substance based on a difference between the first loss power and the second loss power being equal to or greater than a reference value.

[0180] According to one embodiment, in the operating method of the wireless power transmission device (101), the first loss power may include loss power generated in the friendly metal by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and / or the mutual magnetic flux.

[0181] According to one embodiment, in the operating method of the wireless power transmission device (101), the friendly metal may include a first friendly metal of the wireless power reception device (103), a second friendly metal of the wireless power transmission device, the transmission coil (213), and / or the reception coil (221).

[0182] According to one embodiment, in the operating method of the wireless power transmission device (101), the first information may be received through the transmission coil (213). The second information may be received through the transmission coil (213).

[0183] According to one embodiment, the method of operating the wireless power transmission device (101) may include an operation of receiving the first information in a negotiation step for power transmission to the wireless power reception device (103). The method may include an operation of receiving the second information in a power transfer step to the wireless power reception device (103).

[0184] According to one embodiment, in the operating method of the wireless power transmission device (101), the first information may include information on the slope and intercept of the linear relationship between the mutual loss power and the transmission current.

[0185] According to one embodiment, the method of operating the wireless power transmission device (101) may include an operation of calculating a mutual current based on the reception current, the transmission current, and the phase difference between the reception current and the transmission current. The method may include an operation of calculating a mutual resistance based on the mutual current and the mutual loss power. The method may include an operation of calculating the first loss power based on the mutual resistance.

[0186] According to one embodiment, the operating method of the wireless power transmission device (101) may include receiving third information from the wireless power reception device (103) through the transmission coil (213). The third information may include information on a maximum resistance of a transmission resistance of the transmission coil (213). The method may include measuring a first transmission resistance of the transmission coil (213) while the mutual magnetic flux is connected between the transmission coil (213) and the reception coil (221). The method may include calculating the first loss power based on the maximum resistance, based on the first transmission resistance being greater than or equal to the maximum resistance. The method may include calculating the first loss power based on the first transmission resistance being less than the maximum resistance.

[0187] According to one embodiment, the operating method of the wireless power transmission device (101) may include receiving fourth information from the wireless power reception device (103) through the transmission coil (213). The fourth information may include information on a reception resistance of the reception coil (221) related to the transmission resistance of the transmission coil (213). The method may include calculating a first reception resistance of the reception coil (221) based on the fourth information and the first transmission resistance. The method may include calculating the first loss power based on the maximum resistance, based on the first reception resistance being greater than or equal to the maximum resistance. The method may include calculating the first loss power based on the first reception resistance being less than the maximum resistance.

[0188] According to one embodiment, the operating method of the wireless power transmission device (101) may include an operation of receiving fifth information from the wireless power reception device (103) through the transmission coil (213). The fifth information may include information on inverter efficiency of the wireless power transmission device (101) related to the transmission current. The method may include an operation of checking the second loss power based on the inverter efficiency.

[0189] According to one embodiment, in the operating method of the wireless power transmission device (101), the fifth information may include information on the slope and intercept of the linear relationship between the inverter efficiency and the transmission current. The slope of the linear relationship between the inverter efficiency and the transmission current may be determined by the wireless power reception device (103) based on the load resistance of the wireless power reception device (103).

[0190] According to one embodiment, in the operating method of the wireless power transmission device (101), the second information may include information on the input current of the charger of the wireless power reception device (103) and the input voltage of the charger.

[0191] According to one embodiment, in the operating method of the wireless power transmission device (101), the slope of the linear relationship between the mutual loss power and the transmission current can be determined by the wireless power reception device (103) based on the load resistance of the wireless power reception device (103).

[0192] According to one embodiment, a non-transitory computer-readable storage medium storing at least one instruction, wherein the at least one instruction, when executed by at least one controller (215) including a processing circuit of a wireless power transmission device (101), causes the wireless power transmission device (101) to perform at least one operation. The at least one operation may include receiving first information from a wireless power reception device (103). The first information may include information related to a transmission current and mutual loss power of a transmission coil (213) of the wireless power transmission device (101). The at least one operation may include receiving second information from the wireless power reception device (103). The second information may include information related to a reception current of the receiving coil (221) of the wireless power receiving device (103), a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power receiving device (103). The at least one operation may include an operation of measuring a first transmission current of the transmitting coil (213). The at least one operation may include an operation of calculating a first mutual loss power based on the first information and the first transmission current. The at least one operation may include an operation of calculating a first loss power based on the first mutual loss power and the second information. The first loss power may be a loss power generated by a magnetic flux of the transmitting coil (213), a magnetic flux of the receiving coil (221), and a mutual flux connected between the transmitting coil (213) and the receiving coil (221). The at least one operation may include an operation of measuring a second power loss between the wireless power transmission device (101) and the wireless power reception device (103).The at least one operation may include an operation of checking for a foreign substance based on a difference between the first loss power and the second loss power being greater than or equal to a reference value.

[0193] According to one embodiment, in the non-transitory computer-readable storage medium, the first loss power may include loss power generated in the friendly metal by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and / or the mutual magnetic flux.

[0194] According to one embodiment, in the non-transitory computer-readable storage medium, the friendly metal may include the first friendly metal of the wireless power receiving device (103), the second friendly metal of the wireless power transmitting device, the transmitting coil (213), and / or the receiving coil (221).

[0195] According to one embodiment, in the non-transitory computer-readable storage medium, the first information may be received through the transmission coil (213). The second information may be received through the transmission coil (213).

[0196] According to one embodiment, in the non-transitory computer-readable storage medium, the at least one operation may include an operation of receiving the first information in a negotiation step for transferring power to the wireless power receiving device (103). The at least one operation may include an operation of receiving the second information in a power transfer step to the wireless power receiving device (103).

[0197] According to one embodiment, in the non-transitory computer-readable storage medium, the first information may include information about the slope and intercept of a linear relationship between the mutual loss power and the transmission current.

[0198] In one embodiment, in the non-transitory computer-readable storage medium, the at least one operation may include calculating a mutual current based on the received current, the transmitted current, and the phase difference between the received current and the transmitted current. The at least one operation may include calculating a mutual resistance based on the mutual current and the mutual loss power. The at least one operation may include calculating the first loss power based on the mutual resistance.

[0199] According to one embodiment, in the non-transitory computer-readable storage medium, the at least one operation may include receiving third information from the wireless power receiving device (103) via the transmitting coil (213). The third information may include information on a maximum resistance of a transmitting resistance of the transmitting coil (213). The at least one operation may include measuring a first transmitting resistance of the transmitting coil (213) while the mutual magnetic flux is coupled between the transmitting coil (213) and the receiving coil (221). The at least one operation may include calculating the first loss power based on the maximum resistance, based on the first transmitting resistance being greater than or equal to the maximum resistance. The at least one operation may include calculating the first loss power based on the first transmitting resistance being less than the maximum resistance.

[0200] According to one embodiment, in the non-transitory computer-readable storage medium, the at least one operation may include receiving fourth information from the wireless power receiving device (103) via the transmitting coil (213). The fourth information may include information about a receiving resistance of the receiving coil (221) related to the transmitting resistance of the transmitting coil (213). The at least one operation may include calculating a first receiving resistance of the receiving coil (221) based on the fourth information and the first transmitting resistance. The at least one operation may include calculating the first loss power based on the maximum resistance, based on the first receiving resistance being greater than or equal to the maximum resistance. The at least one operation may include calculating the first loss power based on the first receiving resistance being less than the maximum resistance.

[0201] According to one embodiment, in the non-transitory computer-readable storage medium, the at least one operation may include receiving fifth information from the wireless power receiving device (103) via the transmitting coil (213). The fifth information may include information on inverter efficiency of the wireless power transmitting device (101) related to the transmitting current. The at least one operation may include an operation of checking the second power loss based on the inverter efficiency.

[0202] According to one embodiment, in the non-transitory computer-readable storage medium, the fifth information may include information about the slope and intercept of the linear relationship between the inverter efficiency and the transmission current. The slope of the linear relationship between the inverter efficiency and the transmission current may be determined by the wireless power receiving device (103) based on the load resistance of the wireless power receiving device (103).

[0203] According to one embodiment, in the non-transitory computer-readable storage medium, the second information may include information about an input current of a charger of the wireless power receiving device (103) and an input voltage of the charger.

[0204] According to one embodiment, in the non-transitory computer-readable storage medium, the slope of the linear relationship between the mutual loss power and the transmission current can be determined by the wireless power receiving device (103) based on the load resistance of the wireless power receiving device (103).

[0205] According to one embodiment, a wireless power transmitter (101) may include a transmitting coil (213), at least one controller (215) including a processing circuit, and a memory (210) storing instructions. The instructions, when executed by the at least one controller (215), may cause the wireless power transmitter (101) to receive first information from a wireless power receiver (103). The first information may include information regarding an amount of power applied to the transmitting coil (213) related to an amount of mutual loss power due to a friendly metal interfering with a mutual magnetic flux. The mutual magnetic flux may include a magnetic flux coupled between a receiving coil (221) of the wireless power receiver (103) and the transmitting coil (213). The above instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to determine second information regarding a first transmission current applied to the transmission coil (213) while providing wireless charging power through the transmission coil (213). The above instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to determine third information regarding a first power loss that occurs while providing wireless charging power from the wireless power transmission device (101) to the wireless power reception device (103). The above instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to detect a foreign metal object based on the first information, the second information, and the third information while providing wireless charging power through the transmitting coil (213).

[0206] According to one embodiment, in the wireless power transmission device (101), the instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate a first mutual loss power based on the first information and the second information. The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate a second loss power based on the first mutual loss power. The second loss power may include a loss power generated by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and / or the mutual flux. The above instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to detect the foreign metal object based on a difference between the first loss power and the second loss power being greater than or equal to a reference value.

[0207] According to one embodiment, in the wireless power transmission device (101), the instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to receive fourth information from the wireless power reception device (103). The fourth information may include information related to a reception current of the reception coil (221), a phase difference between the reception current and the transmission current of the transmission coil (213), and / or a load resistance of the wireless power reception device (103). The instructions, when executed by at least one controller (215), may cause the wireless power transmission device (101) to calculate the second loss power based on the first mutual loss power and the fourth information.

[0208] According to one embodiment, in the wireless power transmission device (101), the first information may include information about the slope and intercept of a linear relationship between the mutual loss power and the power applied to the transmission coil (213). The first information may include information about a matching table between values ​​corresponding to the mutual loss power and values ​​corresponding to the power applied to the transmission coil (213).

[0209] According to one embodiment, in the wireless power transmission device (101), in the first information, the power applied to the transmission coil (213) may include one of a transmission current applied to the transmission coil (213), a transmission power applied to the transmission coil (213), an output power of an inverter (218) electrically connected to the transmission coil (213), or an input power of the inverter (218).

[0210] Devices according to the various embodiments disclosed in this document may take various forms. The devices may include, for example, portable communication devices (e.g., smartphones), computer devices, portable multimedia devices, portable medical devices, cameras, wearable devices, or home appliances. Devices according to the embodiments of this document are not limited to the aforementioned devices.

[0211] The various embodiments of this document and the terminology used therein are not intended to limit the technical features described in this document to specific embodiments, but should be understood to include various modifications, equivalents, or substitutes of the embodiments. In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of a noun corresponding to an item may include one or more of the items, unless the context clearly indicates otherwise. In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" can include any one of the items listed together in the corresponding phrase among those phrases, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used merely to distinguish one component from another, and do not limit the components in any other respect (e.g., importance or order). When a component (e.g., a first component) is referred to as "coupled" or "connected" to another (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0212] The term "module" used in various embodiments of this document may include a unit implemented in hardware, software, or firmware, and may be used interchangeably with terms such as logic, logic block, component, or circuit. A module may be an integral component, or a minimum unit or part of such a component that performs one or more functions. For example, according to one embodiment, a module may be implemented in the form of an application-specific integrated circuit (ASIC).

[0213] Various embodiments of the present document may be implemented as software (e.g., a program) including one or more instructions stored on a storage medium that can be read by a machine (e.g., an electronic device). For example, a processor (e.g., a controller) of the machine may call at least one instruction among the one or more instructions stored from the storage medium and execute it. This enables the machine to operate to perform at least one function according to the at least one instruction called. The one or more instructions may include code generated by a compiler or code that can be executed by an interpreter. The machine-readable storage medium may be provided in the form of a non-transitory storage medium. Here, 'non-transitory' only means that the storage medium is a tangible device and does not contain a signal (e.g., electromagnetic waves), and this term does not distinguish between cases where data is stored semi-permanently and cases where it is stored temporarily in the storage medium.

[0214] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) via an application store (e.g., Play Store™) or directly between two user devices (e.g., smart phones). In the case of online distribution, at least a portion of the computer program product may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0215] According to various embodiments, each component (e.g., a module or a program) of the above-described components may include one or more entities, and some of the entities may be separated and placed in other components. According to various embodiments, one or more components or operations of the aforementioned components may be omitted, or one or more other components or operations may be added. Alternatively or additionally, a plurality of components (e.g., a module or a program) may be integrated into a single component. In such a case, the integrated component may perform one or more functions of each of the plurality of components identically or similarly to those performed by the corresponding component among the plurality of components prior to the integration. According to various embodiments, the operations performed by a module, program, or other component may be executed sequentially, in parallel, iteratively, or heuristically, or one or more of the operations may be executed in a different order, omitted, or one or more other operations may be added.

[0216] While the present disclosure has been described and illustrated with reference to various exemplary embodiments, it is to be understood that the various exemplary embodiments are illustrative and not limiting. Those skilled in the art will appreciate that various changes in form and detail may be made without departing from the true spirit and scope of the present disclosure, including the appended claims and their equivalents. Furthermore, it will be understood that any one embodiment described herein may be combined with other embodiments.

Claims

1. In a wireless power transmission device (101), Transmitter coil (213); At least one controller (215) comprising a processing circuit; and Includes a memory (210) for storing instructions, The above instructions, when executed by at least one controller (215), cause the wireless power transmission device (101) to: Receive first information from a wireless power receiving device (103), wherein the first information includes information related to the transmission current and mutual loss power of the transmitting coil (213), Receive second information from the wireless power receiving device (103), and the second information includes information related to the reception current of the receiving coil (221) of the wireless power receiving device (103), the phase difference between the reception current and the transmission current, and / or the load resistance of the wireless power receiving device (103). Measure the first transmission current of the above-mentioned transmission coil (213), Based on the first information and the first transmission current, the first mutual loss power is calculated, Based on the first mutual loss power and the second information, a first loss power is calculated, and the first loss power is a loss power generated by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and / or the mutual magnetic flux connected between the transmitting coil (213) and the receiving coil (221). Measure the second power loss between the wireless power transmission device (101) and the wireless power reception device (103), Based on the difference between the first loss power and the second loss power being greater than or equal to a reference value, causing a foreign substance to be identified, Wireless power transmission device (101).

2. In paragraph 1, The first loss power includes the loss power generated in the friendly metal by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and / or the mutual magnetic flux. Wireless power transmission device (101).

3. In paragraph 1 or 2, The friendly metal includes the first friendly metal of the wireless power receiving device (103), the second friendly metal of the wireless power transmitting device, the transmitting coil (213), and / or the receiving coil (221). Wireless power transmission device (101).

4. In any one of paragraphs 1 to 3, The above first information is received through the transmitting coil (213), The above second information is received through the transmitting coil (213). Wireless power transmission device (101).

5. In any one of paragraphs 1 to 4, The above instructions, when executed by at least one controller (215), cause the wireless power transmission device (101) to: In the negotiation step for power transmission to the wireless power receiving device (103), the first information is received, In the power transfer step to the wireless power receiving device (103), causing the second information to be received, Wireless power transmission device (101).

6. In any one of paragraphs 1 to 5, The first information includes information about the slope and intercept of the linear relationship between the mutual loss power and the transmission current. Wireless power transmission device (101).

7. In any one of paragraphs 1 to 6, The above instructions, when executed by at least one controller (215), cause the wireless power transmission device (101) to: Calculate the mutual current based on the received current, the transmitted current, and the phase difference between the received current and the transmitted current, Based on the mutual current and mutual loss power, the mutual resistance is calculated, Based on the above mutual resistance, causing the first loss power to be calculated, Wireless power transmission device (101).

8. In any one of paragraphs 1 to 7, The above instructions, when executed by at least one controller (215), cause the wireless power transmission device (101) to: Receive third information from the wireless power receiving device (103) through the transmitting coil (213), and the third information includes information on the maximum resistance of the transmitting resistance of the transmitting coil (213). While the mutual magnetic flux is connected between the transmitting coil (213) and the receiving coil (221), the first transmitting resistance of the transmitting coil (213) is measured, Based on the first transmission resistance being greater than or equal to the maximum resistance, the first loss power is calculated based on the maximum resistance, Causing the first loss power to be calculated based on the first transmission resistance, based on the first transmission resistance being less than the maximum resistance. Wireless power transmission device (101).

9. In any one of paragraphs 1 to 8, The above instructions, when executed by at least one controller (215), cause the wireless power transmission device (101) to: Receive fourth information from the wireless power receiving device (103) through the transmitting coil (213), and the fourth information includes information on the receiving resistance of the receiving coil (221) related to the transmitting resistance of the transmitting coil (213), Based on the fourth information and the first transmission resistance, the first receiving resistance of the receiving coil (221) is calculated, Based on the first receiving resistance being greater than or equal to the maximum resistance, the first loss power is calculated based on the maximum resistance, Causing the first loss power to be calculated based on the first receiving resistance, based on the first receiving resistance being less than the maximum resistance; Wireless power transmission device (101).

10. In any one of paragraphs 1 to 9, The above instructions, when executed by at least one controller (215), cause the wireless power transmission device (101) to: Receive fifth information from the wireless power receiving device (103) through the transmitting coil (213), wherein the fifth information includes information on the inverter efficiency of the wireless power transmitting device (101) related to the transmitting current, Based on the above inverter efficiency, causing the second loss power to be checked, Wireless power transmission device (101).

11. In any one of paragraphs 1 to 10, The fifth information includes information on the slope and intercept of the linear relationship between the inverter efficiency and the transmission current, The slope of the linear relationship between the inverter efficiency and the transmission current is determined by the wireless power receiving device (103) based on the load resistance of the wireless power receiving device (103). Wireless power transmission device (101).

12. In any one of paragraphs 1 to 11, The second information includes information about the input current of the charger of the wireless power receiving device (103) and the input voltage of the charger. Wireless power transmission device (101).

13. In any one of paragraphs 1 to 12, The slope of the linear relationship between the mutual loss power and the transmission current is determined by the wireless power receiving device (103) based on the load resistance of the wireless power receiving device (103). Wireless power transmission device (101).

14. In the operating method of the wireless power transmission device (101), An operation of receiving first information from a wireless power receiving device (103), wherein the first information includes information related to a transmission current and mutual loss power of a transmission coil (213) of the wireless power transmitting device (101); An operation of receiving second information from the wireless power receiving device (103), wherein the second information includes information related to a reception current of a receiving coil (221) of the wireless power receiving device (103), a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power receiving device (103); An operation of measuring the first transmission current of the above-mentioned transmission coil (213); An operation of calculating a first mutual loss power based on the first information and the first transmission current; An operation of calculating a first loss power based on the first mutual loss power and the second information, wherein the first loss power is a loss power generated by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and the mutual flux connected between the transmitting coil (213) and the receiving coil (221); An operation of measuring a second power loss between the wireless power transmission device (101) and the wireless power reception device (103); and An operation of checking for a foreign substance based on the difference between the first loss power and the second loss power being greater than or equal to a reference value is included. method.

15. In a non-transitory computer-readable storage medium storing at least one instruction, the at least one instruction, when executed by at least one controller (215) including a processing circuit of the wireless power transmission device (101), causes the wireless power transmission device (101) to perform at least one operation, At least one of the above actions: An operation of receiving first information from a wireless power receiving device (103), wherein the first information includes information related to a transmission current and mutual loss power of a transmission coil (213) of the wireless power transmitting device (101); An operation of receiving second information from the wireless power receiving device (103), wherein the second information includes information related to a reception current of a receiving coil (221) of the wireless power receiving device (103), a phase difference between the reception current and the transmission current, and / or a load resistance of the wireless power receiving device (103); An operation of measuring the first transmission current of the above-mentioned transmission coil (213); An operation of calculating a first mutual loss power based on the first information and the first transmission current; An operation of calculating a first loss power based on the first mutual loss power and the second information, wherein the first loss power is a loss power generated by the magnetic flux of the transmitting coil (213), the magnetic flux of the receiving coil (221), and the mutual flux connected between the transmitting coil (213) and the receiving coil (221); An operation of measuring a second power loss between the wireless power transmission device (101) and the wireless power reception device (103); and An operation of checking for a foreign substance based on the difference between the first loss power and the second loss power being greater than or equal to a reference value is included. Storage media.

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