External circuit model, coupler loss calculation method and foreign matter detection method

Abstract

The invention provides an external circuit model, a coupler loss calculation method and a foreign matter detection method, the external circuit model comprises a peripheral circuit and a control circuit, and the peripheral circuit comprises a power supply network, an inverter network, a compensation network, a rectifier network, a load network and a measurement network; the inverter network is connected with the power supply network, converts direct current provided by the power supply network into alternating current based on the inversion control signal and outputs the alternating current to the transmitting side coil; the compensation network is connected with the transmitting side coil and the receiving side coil and is used for compensating inductive impedance of the transmitting side and the receiving side; the rectifier network rectifies the alternating current output by the receiving side coil and then supplies power to the load network; the measuring network is connected with the transmitting side coil and the receiving side coil and is used for measuring voltage and current values of the transmitting side and the receiving side; and the control circuit performs PID control on the PWM signal to generate an inversion control signal. According to the invention, the problem of low foreign matter detection precision caused by incapability of accurately obtaining coupler loss in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless energy transmission, and in particular to an external circuit model, a coupler loss calculation method and a foreign matter detection method. Background Art

[0002] With the continuous advancement of science and technology, wireless charging has become an indispensable part of people's lives today; however, there is also a certain energy loss problem in the wireless charging process, which leads to reduced charging efficiency.

[0003] The factors that affect charging efficiency mainly include coupler loss, and coupler loss mainly includes copper loss and iron loss. In practical applications, these losses are not conducive to the judgment of some parameters in wireless energy transmission; for example, in foreign object detection judgment, if these losses are the same as the losses when foreign objects are present, there may be a situation where foreign objects cannot be detected. Therefore, accurately understanding these losses and performing power compensation to improve the accuracy of foreign object detection is a technical problem that technicians in this field are eager to solve. Summary of the invention

[0004] In view of the shortcomings of the prior art described above, an object of the present invention is to provide an external circuit model, a coupler loss calculation method and a foreign object detection method, so as to solve the problem in the prior art that the coupler loss cannot be accurately obtained, resulting in low foreign object detection accuracy.

[0005] To achieve the above-mentioned object and other related objects, the present invention provides an external circuit model to match a coil model composed of a transmitting side coil and a receiving side coil, wherein the external circuit model includes:

[0006] Peripheral circuits and control circuits, wherein the peripheral circuits include a power supply network, an inverter network, a compensation network, a rectifier network, a load network and a measurement network;

[0007] The power supply network is used to provide direct current;

[0008] The inverter network is connected to the power supply network, and converts the direct current into alternating current based on an inverter control signal and outputs it to the transmitting side coil;

[0009] The compensation network is connected to the transmitting side coil and the receiving side coil, and is used to compensate for the inductive impedance of the transmitting side and the receiving side;

[0010] The load network is connected to the rectifier network, and the rectifier network is used to rectify the alternating current output by the receiving side coil and then supply power to the load network;

[0011] The measurement network is connected to the transmitting side coil and the receiving side coil, and is used to measure the voltage value and the current value of the transmitting side and the receiving side;

[0012] The control circuit generates the inverter control signal by performing PID control on the PWM signal.

[0013] Optionally, the compensation network includes a first capacitor, a second capacitor and a first inductor;

[0014] The first capacitor is connected in series or in parallel with the transmitting side coil, the second capacitor is connected in series or in parallel with the receiving side coil, and the first inductor is connected in series between the inverter network and the first capacitor.

[0015] Optionally, the power supply network includes a DC power supply and a first resistor, the positive electrode of the DC power supply is connected to the first end of the first resistor, the negative electrode is grounded, and the second end of the first resistor outputs the DC power.

[0016] Optionally, the load network includes a second resistor and a third capacitor, which are respectively connected in parallel to two ends of the rectifier network.

[0017] Optionally, the measurement network includes a first voltmeter, a second voltmeter, a first ammeter and a second ammeter, the first voltmeter is connected in parallel to both ends of the transmitting side coil, the second voltmeter is connected in parallel to both ends of the receiving side coil, the first ammeter is connected in series to the first end of the transmitting side coil, and the second ammeter is connected in series to the first end of the receiving side coil.

[0018] The present invention also provides a method for calculating coupler loss of a wireless transmission system, the method comprising:

[0019] Conduct electromagnetic simulation on the transmitting coil and the receiving coil to establish a 3D dynamic coil model;

[0020] Constructing the external circuit model as described above, and combining the coil model with the external circuit model to obtain a wireless transmission system model;

[0021] The system parameters are configured, and the wireless transmission system model is simulated and analyzed to obtain the copper loss and iron loss, thereby obtaining the coupler loss.

[0022] Optionally, the method for obtaining the copper loss includes: obtaining the primary loss and the secondary loss of the coil model, and obtaining the copper loss based on the primary loss and the secondary loss;

[0023] Wherein, the copper loss satisfies the formula P coil =P Lp +P Ls =I p U p +I s U s , P coil is the copper loss, PLp is the primary side loss, P Ls is the secondary side loss, I p is the primary current, U p is the primary voltage, I s is the secondary current, U s is the secondary voltage.

[0024] Optionally, the method for obtaining the iron loss includes: extracting external features of the loss feature based on the coil model parameters in the system parameters and obtaining the iron loss therefrom;

[0025] Among them, the external characteristics of the loss characteristics satisfy the formula P is the magnetic susceptibility, B is the magnetic induction intensity, μ 0 is the vacuum magnetic permeability, and H is the magnetic field strength.

[0026] The present invention also provides a foreign body detection method for a wireless transmission system, the foreign body detection method comprising:

[0027] Measuring the transmitting side power and receiving side power of the wireless transmission system, and obtaining the coupler loss based on the coupler loss calculation method as described above, and then performing power compensation on the transmitting side power by the coupler loss to obtain the transmitting side compensation power;

[0028] The transmitting side compensation power and the receiving side power are compared, and foreign object detection is performed based on the comparison result.

[0029] Optionally, the foreign object detection method further includes: controlling whether the wireless energy transmission is terminated based on the foreign object detection result.

[0030] As described above, the external circuit model, coupler loss calculation method and foreign object detection method of the present invention can accurately obtain the coupler loss through the design of the external circuit model and the automatic simulation with the coil model; power compensation and foreign object detection based on the coupler loss can improve the accuracy of foreign object detection; the method involved in the present invention has the advantages of accuracy, simplicity, convenience and speed when executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Shown is a structural schematic diagram of the peripheral circuit of the present invention.

[0032] Figure 2 Another structural schematic diagram of the peripheral circuit of the present invention is shown.

[0033] Figure 3 Shown is another structural schematic diagram of the peripheral circuit of the present invention.

[0034] Figure 4 Shown is another structural schematic diagram of the peripheral circuit of the present invention.

[0035] Figure 5 Shown is a schematic diagram of the structure of the control circuit of the present invention.

[0036] Figure 6 Shown is a flow chart of the method for calculating coupler loss of the present invention.

[0037] Figure 7 Shown is a flow chart of the foreign body detection method of the present invention.

[0038] Component number description

[0039] 100 Peripheral Circuit

[0040] 101 Power Network

[0041] 102 Inverter Network

[0042] 103 Compensation Network

[0043] 104 Rectifier Network

[0044] 105 Load Network

[0045] 106 Measurement Network

[0046] 200 Control circuit DETAILED DESCRIPTION

[0047] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0048] See also Figures 1 to 7 It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the form, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0049] like Figures 1 to 5 As shown, this embodiment provides an external circuit model for matching a coil model composed of a transmitting side coil TX and a receiving side coil RX to form a wireless transmission system model; the external circuit model includes a peripheral circuit 100 and a control circuit 200, wherein the peripheral circuit 100 includes a power supply network 101, an inverter network 102, a compensation network 103, a rectifier network 104, a load network 105 and a measurement network 106.

[0050] The power supply network 101 is used to provide direct current.

[0051] As an example, Figure 1 As shown, the power supply network 101 includes a DC power supply E1 and a first resistor R1, wherein the positive electrode of the DC power supply E1 is connected to the first end of the first resistor R1, the negative electrode is grounded, and the second end of the first resistor R1 outputs DC power. The DC power supply E1 can be obtained by rectifying an AC power supply.

[0052] The inverter network 102 is connected to the power supply network 101, and converts direct current into alternating current based on an inverter control signal and outputs it to the transmitting side coil TX, so that the transmitting side coil TX generates an alternating magnetic field based on the alternating current for wireless energy transmission, thereby enabling the receiving side coil RX to generate an alternating current output under the action of the alternating magnetic field.

[0053] As an example, Figure 1 As shown, the inverter network 102 includes a full-bridge inverter. In a possible implementation, the full-bridge inverter includes a first power switch tube Q1, a second power switch tube Q2, a third power switch tube Q3, and a fourth power switch tube Q4. At this time, the inverter control signal includes a first control signal G1, a second control signal G2, a third control signal G3, and a fourth control signal G4.

[0054] Among them, the control end of the first power switch tube Q1 receives the first control signal G1, the first end is connected to the first end of the third power switch tube Q3 and receives the direct current output by the power supply network 111 (that is, connected to the second end of the first resistor R1), and the second end is connected to the first end of the second power switch tube Q2 and serves as the first output end of the full-bridge inverter; the control end of the second power switch tube Q2 receives the second control signal G2, the second end is connected to the second end of the fourth power switch tube Q4 and grounded; the control end of the third power switch tube Q3 receives the third control signal G3, the second end is connected to the first end of the fourth power switch tube Q4 and serves as the second output end of the full-bridge inverter; the control end of the fourth power switch tube Q4 receives the fourth control signal G4.

[0055] In practical applications, each power switch tube can be an insulated gate bipolar transistor IGBT or a metal-oxide semiconductor field effect transistor MOSFET; when each power switch tube is an insulated gate bipolar transistor IGBT, the control end refers to the gate, the first end refers to the collector, and the second end refers to the emitter; when each power switch tube is a metal-oxide semiconductor field effect transistor, the control end refers to the gate, the first end refers to the drain, and the second end refers to the source.

[0056] When a full-bridge inverter is used to implement the inverter function, since the full-bridge inverter includes four power switch tubes, the voltage value borne by each power switch tube is relatively small, which can reduce the voltage stress of the power switch tube. At the same time, the full-bridge inverter has a high transmission efficiency and is easy to implement soft switching.

[0057] The compensation network 103 is connected to the transmitting side coil TX and the receiving side coil RX, and is used to compensate for the inductive impedance of the transmitting side and the receiving side.

[0058] As an example, Figures 1 to 4 As shown, the compensation network 103 includes a first capacitor C1, a second capacitor C2 and a first inductor L1; the first capacitor C1 is connected in series or in parallel with the transmitting side coil TX, the second capacitor C2 is connected in series or in parallel with the receiving side coil RX, and the first inductor L1 is connected in series between the inverter network 102 and the first capacitor C1.

[0059] In practical applications, the connection combinations of the first capacitor C1 and the transmitting coil TX and the second capacitor C2 and the receiving coil RX include four types: series-series, series-parallel, parallel-series and parallel-parallel.

[0060] For series-series connection: Figure 1 As shown, the first capacitor C1 is connected in series between the first output end of the inverter network 102 and the first end of the transmitting side coil TX, the second capacitor C2 is connected in series between the first end of the receiving side coil RX and the first input end of the rectifier network 104, and the first inductor L1 is connected in series between the first output end of the inverter network 102 and the first end of the first capacitor C1.

[0061] For series-parallel connection: Figure 2 As shown, the first capacitor C1 is connected in series between the first output end of the inverter network 102 and the first end of the transmitting side coil TX, the second capacitor C2 is connected in parallel between the two ends of the receiving side coil RX, and the first inductor L1 is connected in series between the first output end of the inverter network 102 and the first end of the first capacitor C1.

[0062] For parallel-series connection: Figure 3 As shown, the first capacitor C1 is connected in parallel between the two ends of the transmitting side coil TX, the second capacitor C2 is connected in series between the first end of the receiving side coil RX and the first input end of the rectifier network 104, and the first inductor L1 is connected in series between the first output end of the inverter network 102 and the first end of the first capacitor C1.

[0063] For parallel-parallel form: Figure 4As shown, the first capacitor C1 is connected in parallel between the two ends of the transmitting side coil TX, the second capacitor C2 is connected in parallel between the two ends of the receiving side coil RX, and the first inductor L1 is connected in series between the first output end of the inverter network 102 and the first end of the first capacitor C1.

[0064] Since the medium of wireless energy transmission is mainly a coupling coil, that is, the transmitting side coil TX and the receiving side coil RX, the material of which is usually a wire, the circuit impedance of the transmitting side and the receiving side is inductive, and the addition of inductive impedance will reduce the system power factor, resulting in reduced system transmission efficiency; by adding a compensation network 103, the inductive impedance of the transmitting side and the receiving side is compensated, which can improve the system power factor and improve the system transmission efficiency.

[0065] The load network 105 is connected to the rectifier network 104 , and the rectifier network 104 is used to rectify the alternating current output by the receiving side coil RX and then supply power to the load network 105 .

[0066] As an example, Figure 1 As shown, the rectifier network 104 includes a full-bridge rectifier. In one possible implementation, the full-bridge rectifier includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4.

[0067] Among them, the anode of the first diode D1 is connected to the cathode of the second diode D2 and serves as the first input end of the full-bridge rectifier, and the cathode is connected to the cathode of the third diode D3 and serves as the first output end of the full-bridge rectifier; the anode of the second diode D2 is connected to the anode of the fourth diode D4 and serves as the second output end of the full-bridge rectifier; the anode of the third diode D3 is connected to the cathode of the fourth diode D4 and serves as the second input end of the full-bridge rectifier.

[0068] When the second capacitor C2 exists in series in the compensation network 103, the first input end of the full-bridge rectifier is connected to the second end of the second capacitor C2, and the second input end is connected to the second end of the receiving side coil RX; when the second capacitor C2 exists in parallel in the compensation network 103, the two input ends of the full-bridge rectifier are correspondingly connected to the two ends of the second capacitor C2.

[0069] As an example, Figure 1 As shown, the load network 105 includes a second resistor R2 and a third capacitor C3, which are respectively connected in parallel to two ends of the rectifier network 104.

[0070] The measurement network 106 is connected to the transmitting side coil TX and the receiving side coil RX, and is used to measure the voltage value and the current value of the transmitting side and the receiving side.

[0071] As an example, Figure 1As shown, the measurement network 106 includes a first voltmeter V1 , a second voltmeter V2 , a first ammeter A1 , and a second ammeter A2 .

[0072] The first voltmeter V1 is connected in parallel to both ends of the transmitting coil TX, and is used to measure the voltage of the transmitting side, that is, the primary voltage. The first ammeter A1 is connected in series to the first end of the transmitting coil TX, and is used to measure the current of the transmitting side, that is, the primary current; when the first capacitor C1 exists in series in the compensation network 103, the first ammeter A1 is connected in series between the second end of the first capacitor C1 and the first end of the transmitting coil TX; when the first capacitor C1 exists in parallel in the compensation network 103, the first ammeter A1 is connected in series between the first end of the first capacitor C1 and the first end of the transmitting coil TX.

[0073] The second voltmeter V2 is connected in parallel to both ends of the receiving coil RX, and is used to measure the voltage on the receiving side, i.e., the secondary voltage. The second ammeter A2 is connected in series to the first end of the receiving coil RX, and is used to measure the current on the receiving side, i.e., the secondary current; regardless of whether the second capacitor C2 in the compensation network 103 exists in series or in parallel, the second ammeter A2 is connected in series between the first end of the receiving coil RX and the first end of the second capacitor C2.

[0074] The control circuit 200 generates an inverter control signal by performing PID control on the PWM signal.

[0075] As an example, Figure 5 As shown, the control circuit 200 includes a first signal network 201, a second signal network 202, a third signal network 203 and a fourth signal network 204; wherein the first signal network 201 is used to generate a PWM signal as a first control signal G1 output; the second signal network 202 is used to output the reverse signal of the PWM signal as a second control signal G2; the third signal network 203 is connected to the second signal network 202, and is used to perform PID control on the second control signal G2 to obtain a third control signal G3 output; the fourth signal network 204 is connected to the first signal network 201, and is used to perform PID control on the first control signal G1 to obtain a fourth control signal G4 output.

[0076] Correspondingly, such as Figure 6 As shown, this embodiment also provides a method for calculating coupler loss of a wireless transmission system, and the method for calculating coupler loss includes the following steps.

[0077] Step S11 , performing electromagnetic simulation on the transmitting side coil TX and the receiving side coil RX to establish a 3D dynamic coil model.

[0078] In a possible implementation, taking the transmitting side coil TX and the receiving side coil RX as planar hollow coils as an example, the Maxwell software is used to perform electromagnetic simulation on the transmitting side coil TX and the receiving side coil RX based on the planar hollow coil model to establish the coil model.

[0079] Step S12, build an external circuit model, and combine the coil model with the external circuit model to obtain a wireless transmission system model; wherein the external circuit model is implemented using the model structure as described above, including a peripheral circuit 100 and a control circuit 200, and the relevant contents are detailed above and will not be repeated here.

[0080] In one possible implementation, the peripheral circuit 100 is built using Simplorer software, and the control circuit 200 is built using Matlab software. The peripheral circuit 100 built by the Simplorer software is combined with the control circuit 200 built by the Matlab software to obtain an external circuit model, and then combined with the coil model built by the Maxwell software to obtain a wireless transmission system model. Of course, in other possible implementations, only the Simplorer software can be used to build the peripheral circuit 100 and the control circuit 200 to obtain the external circuit model, which has no substantial impact on the present embodiment.

[0081] Step S13, configuring system parameters, and performing simulation analysis on the wireless transmission system model to obtain copper loss and iron loss, thereby obtaining coupler loss.

[0082] The system parameters include parameters of each device in the external circuit model, such as the values ​​of the DC power supply E1, the first inductor L1, the first capacitor C1, the second capacitor C2, the third capacitor C3, the first resistor R1, and the second resistor R2, and parameters of each coil in the coil model, such as the material of each coil, vacuum magnetic permeability, magnetic induction intensity, magnetic field intensity, etc. In practical applications, the parameters of the transmitting side coil and the receiving side coil are exactly the same.

[0083] The method of obtaining the copper loss includes: obtaining the primary loss and the secondary loss of the coil model, and obtaining the copper loss based on the primary loss and the secondary loss. The copper loss satisfies Formula 1: P coil =P Lp +P Ls =I p U p +I s U s ;P coil is the copper loss, P Lp is the primary side loss, P Ls is the secondary side loss, I p is the primary current, i.e. the measured value of the first ammeter A1, U p is the primary voltage, i.e. the measured value of the first voltmeter V1, Is is the secondary current, i.e. the measured value of the second ammeter A2, U s is the secondary voltage, that is, the measurement value of the second voltmeter V2.

[0084] The method for obtaining the iron loss includes: extracting the external characteristics of the loss characteristics (ie, the BP curve) based on the coil model parameters in the system parameters, and obtaining the iron loss based on the external characteristics.

[0085] The extraction process is as follows: The magnetic induction intensity and magnetic field intensity satisfy the formula 2: B = μ 0 (H+M), B is the magnetic induction intensity, μ 0 is the vacuum magnetic permeability, H is the magnetic field intensity, and M is the magnetization intensity; the magnetization intensity M is obtained based on formula 2, which satisfies formula 3: The BP curve is obtained based on the solution formula of magnetic susceptibility P, which satisfies formula 4:

[0086] Correspondingly, such as Figure 7 As shown, this embodiment also provides a foreign object detection method for a wireless transmission system, and the foreign object detection method includes the following steps.

[0087] Step S1, measuring the transmitting side power and receiving side power of the wireless transmission system, and obtaining the coupler loss based on the coupler loss calculation method as described above, and then performing power compensation on the transmitting side power by the coupler loss to obtain the transmitting side compensation power.

[0088] The relevant contents of the coupler loss calculation method based on the coupler loss are detailed above and will not be repeated here. When performing power compensation, the coupler loss is added to the transmitting side power to achieve power compensation. The coupler loss affects the transmission efficiency of the system, causing the output power of the wireless transmission system to be lower than the input power, that is, the transmitting side power is lower than the receiving side power; by adding the coupler loss to the transmitting side power, the power compensation of the transmitting side is achieved.

[0089] Step S2, compare the transmitting side compensation power and the receiving side power, and perform foreign object detection based on the comparison result; for example, if the difference between the transmitting side compensation power and the receiving side power is greater than or equal to the set threshold, there is a foreign object between the transmitting side and the receiving side of the wireless transmission system; otherwise, there is no foreign object between the transmitting side and the receiving side of the wireless transmission system.

[0090] The foreign object detection method also includes step S3, controlling whether the wireless energy transmission is terminated based on the foreign object detection result; for example, if a foreign object is present, the wireless energy transmission is terminated, otherwise, the wireless energy transmission is continued; wherein, whether the wireless energy transmission is terminated can be achieved by controlling relevant devices on the transmitting side, such as controlling a DC power supply or an inverter network.

[0091] In summary, the external circuit model, the coupler loss calculation method and the foreign body detection method of the present invention can accurately obtain the coupler loss through the design of the external circuit model and the automatic simulation with the coil model; the power compensation and foreign body detection based on the coupler loss can improve the foreign body detection accuracy; the method involved in the present invention has the advantages of accuracy, simplicity, convenience and speed when executed. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has a high industrial utilization value.

[0092] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. An external circuit model, matching a coil model consisting of a transmitting side coil and a receiving side coil, It is characterized in that The external circuit model includes: Peripheral circuits and control circuits, wherein the peripheral circuits include a power supply network, an inverter network, a compensation network, a rectifier network, a load network and a measurement network; The power supply network is used to provide direct current; The inverter network is connected to the power supply network, and converts the direct current into alternating current based on an inverter control signal and outputs it to the transmitting side coil; The compensation network is connected to the transmitting side coil and the receiving side coil, and is used to compensate for the inductive impedance of the transmitting side and the receiving side; The load network is connected to the rectifier network, and the rectifier network is used to rectify the alternating current output by the receiving side coil and then supply power to the load network; The measurement network is connected to the transmitting side coil and the receiving side coil, and is used to measure the voltage value and the current value of the transmitting side and the receiving side; The control circuit generates the inverter control signal by performing PID control on the PWM signal.

2. The external circuit model according to claim 1, It is characterized in that The compensation network includes a first capacitor, a second capacitor and a first inductor; The first capacitor is connected in series or in parallel with the transmitting side coil, the second capacitor is connected in series or in parallel with the receiving side coil, and the first inductor is connected in series between the inverter network and the first capacitor.

3. The external circuit model according to claim 1, It is characterized in that The power supply network includes a DC power supply and a first resistor, wherein the positive electrode of the DC power supply is connected to the first end of the first resistor, the negative electrode is grounded, and the second end of the first resistor outputs the DC power.

4. The external circuit model according to claim 1, It is characterized in that The load network includes a second resistor and a third capacitor, which are respectively connected in parallel to two ends of the rectifier network.

5. The external circuit model according to claim 1, It is characterized in that The measurement network includes a first voltmeter, a second voltmeter, a first ammeter and a second ammeter. The first voltmeter is connected in parallel to the two ends of the transmitting side coil, the second voltmeter is connected in parallel to the two ends of the receiving side coil, the first ammeter is connected in series to the first end of the transmitting side coil, and the second ammeter is connected in series to the first end of the receiving side coil.

6. A method for calculating coupler loss in a wireless transmission system. It is characterized in that The coupler loss calculation method comprises: Conduct electromagnetic simulation on the transmitting coil and the receiving coil to establish a 3D dynamic coil model; Constructing the external circuit model as described in any one of claims 1 to 5, and combining the coil model with the external circuit model to obtain a wireless transmission system model; The system parameters are configured, and the wireless transmission system model is simulated and analyzed to obtain the copper loss and iron loss, thereby obtaining the coupler loss.

7. The method for calculating coupler loss of a wireless transmission system according to claim 6, It is characterized in that Methods for obtaining copper loss include: Obtaining the primary loss and the secondary loss of the coil model, and obtaining the copper loss based on the primary loss and the secondary loss; Wherein, the copper loss satisfies the formula P coil =P Lp +P Ls =I p U p +I s U s , P coil is the copper loss, P Lp is the primary side loss, P Ls is the secondary side loss, I p is the primary current, U p is the primary voltage, I s is the secondary current, U s is the secondary voltage.

8. The method for calculating coupler loss of a wireless transmission system according to claim 6, It is characterized in that Methods for obtaining iron loss include: Extracting external features of loss characteristics based on coil model parameters in the system parameters and obtaining iron loss therefrom; Among them, the external characteristics of the loss characteristics satisfy the formula P is the magnetic susceptibility, B is the magnetic induction intensity, μ 0 is the vacuum magnetic permeability, and H is the magnetic field strength.

9. A foreign body detection method for a wireless transmission system, It is characterized in that The foreign body detection method comprises: Measuring the transmitting side power and receiving side power of the wireless transmission system, and obtaining the coupler loss based on the coupler loss calculation method described in any one of claims 6 to 8, and then performing power compensation on the transmitting side power by the coupler loss to obtain the transmitting side compensation power; The transmitting side compensation power and the receiving side power are compared, and foreign object detection is performed based on the comparison result.

10. The foreign body detection method of the wireless transmission system according to claim 9, It is characterized in that The foreign object detection method further includes: controlling whether the wireless energy transmission is terminated based on the foreign object detection result.

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