High-power wireless energy foreign matter detection device and method based on signal coil multiplexing

Abstract

The invention relates to the technical field of wireless charging, in particular to a signal coil multiplexing-based high-power wireless energy foreign matter detection device and method.The signal coil multiplexing-based high-power wireless energy foreign matter detection device comprises an energy transmission module, a data communication module and a foreign matter detection module, and the data communication module is electrically connected with the energy transmission module and the foreign matter detection module; the energy transmission module is used for achieving wireless transmission of electric energy from a direct-current power source to a load and providing needed electric energy for the load, the signal detection coil and the power coil are reasonably arranged in space, magnetic field changes caused by metal foreign matter can be sensed, interference of a high-intensity magnetic field of the power coil to the energy transmission module is reduced as much as possible, and the energy transmission module is used for achieving wireless transmission of the electric energy from the direct-current power source to the load and providing needed electric energy for the load. The effect of coil multiplexing is realized, so that more detection coils can be arranged in a limited space, the detection range is expanded, and the comprehensiveness of foreign matter detection in a wireless charging area is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless charging, and particularly relates to a foreign object detection device and method for high-power wireless energy based on signal coil multiplexing. Background Art

[0002] During wireless charging, in order to ensure that there is no interference from metals or other harmful objects during the charging process, it is necessary to detect foreign objects in high-power wireless energy to prevent potential safety hazards. Currently, the common method for detecting foreign objects in high-power wireless energy is to detect foreign objects by measuring the change in magnetic flux and induced voltage of the detection coil caused by metal foreign objects. To achieve this goal, special detection coils are required to sense the change in the magnetic field. The design, layout, and parameter selection of these detection coils are all aimed at maximizing the capture of the magnetic field change caused by metal foreign objects, so as to ensure the accuracy and sensitivity of the detection. However, the above detection method usually relies on a single or multiple fixed detection coils to monitor the change in magnetic flux, which limits the detection range to the size and layout of the detection coils. It may not be able to fully cover the entire wireless charging area, resulting in detection blind spots. Therefore, we need to propose a foreign object detection device and method for high-power wireless energy based on signal coil multiplexing to solve the above problems, enabling it to arrange more detection coils in a limited space through coil multiplexing technology, thereby expanding the detection range and ensuring the comprehensiveness of foreign object detection in the wireless charging area. Summary of the Invention

[0003] In view of the above problems, the present invention provides a foreign object detection device for high-power wireless energy based on signal coil multiplexing, including an energy transmission module, a data communication module, and a foreign object detection module. The data communication module is electrically connected to the energy transmission module and the foreign object detection module respectively. The energy transmission module is used to realize the wireless transmission of electrical energy from a DC power supply to a load and provide the required electrical energy for the load. The data communication module is used to realize data communication between the primary side and the secondary side to ensure the coordinated operation of the energy transmission module and the foreign object detection module. The data communication module includes an MCU, a primary side data transceiver circuit, and a secondary side data transceiver circuit. The MCU is electrically connected to the primary side data transceiver circuit and the secondary side data transceiver circuit respectively. The primary side data transceiver circuit and the secondary side data transceiver circuit are located on both sides of the power coil. The foreign object detection module is used to detect whether there are metal foreign objects in the high-power wireless energy transmission area to ensure the safe operation of the system. The foreign object detection module includes a control switch, a foreign object detection circuit, and a signal detection coil for decoupling from the power coil. One end of the control switch is connected to one end of the signal detection coil. The other end of the signal detection coil is respectively connected to one end of the foreign object detection circuit and one end of the primary data transceiver circuit. The other end of the foreign object detection circuit and the other end of the primary data transceiver circuit are respectively connected to the other two ends of the control switch.

[0004] Further, the energy transmission module includes a DC power supply, a DC-AC converter, a compensation network, a power coil, and a load. The DC power supply is connected to the input end of the DC-AC converter. The power coil includes a transmitting coil and a receiving coil. The compensation network is connected between the transmitting coil and the receiving coil. Compensation networks are connected to both the receiving coil and the transmitting coil. The load is located at the other end of the compensation network at the receiving coil. The DC-AC converter is located at the other end of the compensation network at the transmitting coil.

[0005] Further, the process of wireless energy transmission by the energy transmission module is as follows: A1. Directly provide a DC voltage for the DC-AC converter through the DC power supply; A2. The DC-AC converter converts direct current into alternating current according to the control signal of the MCU; A3. After the AC voltage passes through the compensation network, the transmitting coil and the receiving coil reach the resonant state; A4. The transmitting coil generates an alternating magnetic field under the excitation of the alternating current. According to Faraday's law of electromagnetic induction, calculate the electromotive force induced in the receiving coil. The calculation formula is as follows: , where N is the number of turns of the receiving coil, is the magnetic flux, e is the electromotive force, is the magnetic flux is the change amount of the magnetic flux, is the change amount of time; A5. The alternating current induced in the receiving coil is supplied to the load after passing through the secondary compensation network, and calculate the power on the load. The calculation formula is as follows: , where P is the power, U is the effective value of the voltage across the load, and is the resistance value of the load.

[0006] Further, in step A3, the compensation network performs power compensation by connecting a capacitor in series with the transmitting coil and the receiving coil. The calculation formula for the resonant frequency during power compensation is as follows: , where, is the resonant frequency, L is the inductance value of the coil, and C is the capacitance value of the series capacitor. In the resonant state, the impedance of the circuit is minimized and the energy transfer efficiency is maximized.

[0007] Further, the process of the primary data transceiver circuit transmitting data to the secondary data transceiver circuit is as follows: B1. The MCU encodes the data to be transmitted and then modulates it through the primary data transceiver circuit; B2. The modulated signal is transmitted through the transmitting coil. After the receiving coil of the secondary data transceiver circuit receives the signal, it performs amplification and filtering processing; B3. The secondary data transceiver circuit demodulates the received signal to recover the original data signal, and then sends a handshake signal to the primary side. The primary side determines whether it has received the handshake signal. If it has received it, power transmission is performed. If it has not received the handshake signal, it continues to wait.

[0008] Further, in step B1, the modulation formula of the primary data transceiver circuit is: , where is the modulated signal, is the modulation index, is the baseband signal, is the amplitude of the carrier voltage, is the angular frequency.

[0009] C1. After the foreign object detection circuit is powered on, it confirms the magnetic flux of the signal detection coil and performs foreign object detection through the signal detection coil; C2. When a metal foreign object enters the vicinity of the power coil, the magnetic flux of the signal detection coil changes. The changed magnetic flux is , where is the change in magnetic flux caused by the foreign object, is the changed magnetic flux; C3. Calculate the induced voltage generated in the signal detection coil based on the changed magnetic flux. The calculation formula is as follows: , where is the calculated induced voltage, is the number of turns of the signal detection coil, is the change in magnetic flux of the signal detection coil, is the change in time; C4. Amplify the calculated induced voltage; C5. Filter the amplified voltage value; C6. Sample the filtered voltage value through an AD converter to convert the continuous analog signal into a discrete voltage value sequence; After the MCU receives the digital signal output by the AD converter, it calculates the characteristic parameters. The calculation formula for the characteristic parameters is as follows: , where A is the characteristic parameter value, M is the total number of samples, and x(n) is the input characteristic data; C8. Compare the calculated characteristic parameters with a preset threshold. If the characteristic parameters exceed the preset threshold, it is determined that there is a foreign object, and corresponding measures are taken according to the system settings; if the characteristic parameters do not exceed the preset threshold, it is determined that there is no foreign object, and the control switch is controlled to connect the primary data transceiver circuit to the signal detection coil, and enter the data communication and power transmission process.

[0010] Further, in step C4, the formula for the amplification process is as follows: , where is the amplified voltage, is the feedback resistor, is the input resistor, is the induced voltage.

[0011] Further, in step C5, the formula for the filtering process is as follows: , where is the filtering coefficient, is the current input value of the induced voltage, is the input value of the induced voltage at the previous moment, is the time, is the output value after filtering.

[0012] Based on the foreign object detection device for high-power wireless energy based on signal coil multiplexing described above, the present invention also provides a foreign object detection method for high-power wireless energy based on signal coil multiplexing, including the following steps: S1. The MCU controls the control switch to connect the signal detection coil to the foreign object detection circuit, so that the signal detection coil is in a state of preparing to detect foreign objects; S2. Determine whether there is a foreign object. If there is a foreign object, the MCU controls to maintain the foreign object detection state. If there is no foreign object, then enter S3; in the foreign object detection state, continuously monitor whether there is an abnormality during the working process. If there is an abnormality, turn off the device; S3. The MCU controls the control switch to connect the primary data transceiver circuit to the signal detection coil; S4. The secondary data transceiver circuit receives and decodes the data, and simultaneously sends a handshake signal to the primary side; S5. Confirm whether the primary side has received the handshake signal sent by the secondary side. If the handshake signal is not received, the MCU controls to maintain the foreign object detection state; if the handshake signal is received, then perform power transmission; S6. The signal detection coil on the secondary side is connected to the foreign object detection circuit to determine whether there is a foreign object. If there is a foreign object, the MCU controls the energy transmission module to stop power transmission. If there is no foreign object, the MCU controls the control switch to connect the secondary data transceiver circuit to the signal detection coil. S7. The primary side receives and decodes data and simultaneously sends a handshake signal to the secondary side. S8. Confirm whether the secondary side has received the handshake signal sent by the primary side. If the handshake signal is received, power transmission is carried out, and it returns to S6. If the handshake signal is not received, the MCU controls the energy transmission module to stop power transmission.

[0013] The beneficial effects of the present invention are: Through the reasonable layout of the signal detection coil and the power coil in space, the present invention can not only sense the magnetic field change caused by metal foreign objects, but also minimize the interference of the strong magnetic field of the power coil on it, achieving the effect of coil multiplexing, enabling more detection coils to be arranged in a limited space, thereby expanding the detection range and ensuring the comprehensiveness of foreign object detection in the wireless charging area.

[0014] Through the cooperation of the energy transmission module, the data communication module and the foreign object detection module, after completing data communication or during power transmission, the MCU will control the control switch again at a certain time interval or according to the conditions set by the system to connect the coil to the foreign object detection circuit for periodic foreign object detection to monitor in real time whether there is a foreign object entering the vicinity of the power coil and ensure the safety of the system during the entire operation process.

[0015] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will be obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, the claims and the drawings. Brief Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 Shows a schematic diagram of the detection device system according to an embodiment of the present invention; Figure 2 Shows a flowchart of the wireless energy transmission of the energy transmission module according to an embodiment of the present invention; Figure 3The flowchart shows the process of the primary-side data transceiver circuit transmitting data to the secondary-side data transceiver circuit according to an embodiment of the present invention; Figure 4 The flowchart shows the detection method according to an embodiment of the present invention. Detailed implementation manners

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] An embodiment of the present invention provides a foreign object detection device for high-power wireless energy based on signal coil multiplexing, as Figures 1-3 shown, which includes an energy transmission module, a data communication module, and a foreign object detection module. The data communication module is electrically connected to the energy transmission module and the foreign object detection module respectively. The energy transmission module is used to realize the wireless transmission of electric energy from a DC power supply to a load and provide the required electric energy for the load; The energy transmission module includes a DC power supply, a DC-AC converter, a compensation network, a power coil, and a load. The DC power supply is connected to the input end of the DC-AC converter. The power coil includes a transmitting coil and a receiving coil. The compensation network is connected between the transmitting coil and the receiving coil. The receiving coil and the transmitting coil are both connected with a compensation network. The load is located at the other end of the compensation network at the receiving coil, and the DC-AC converter is located at the other end of the compensation network at the transmitting coil; A stable DC electric energy is provided by the DC power supply as the initial source of energy for the entire system; the DC-AC converter is used to convert the DC power provided by the DC power supply into AC power, and the output AC power frequency and amplitude can be adjusted according to system requirements to provide a suitable AC power supply for subsequent wireless energy transmission. The compensation network compensates the reactive power in the process of wireless energy transmission through the combination of inductance and capacitance, so that the transmitting coil and the receiving coil reach the resonance state, thereby improving the energy transmission efficiency and power factor; the transmitting coil generates an alternating magnetic field under the excitation of the alternating current, and the receiving coil receives the alternating magnetic field energy through electromagnetic induction and converts it into alternating current to realize the wireless energy transmission; the load is used to consume the electric energy transmitted by the receiving coil and convert the electric energy into other forms of energy, such as charging a battery, driving an electrical device, etc.

[0020] As Figure 2 shown, the process of the energy transmission module for wireless energy transmission is as follows: A1. Provide a DC voltage directly to the DC-AC converter through a DC power supply; A2. The DC-AC converter converts the direct current into alternating current according to the control signal of the MCU; A3. After the AC voltage passes through the compensation network, the transmitting coil and the receiving coil reach the resonant state; The compensation network performs power compensation by connecting a capacitor in series with the transmitting coil and the receiving coil. The calculation formula for the resonant frequency during power compensation is as follows: , where is the resonant frequency, L is the inductance value of the coil, C is the capacitance value of the series capacitor. In the resonant state, the impedance of the circuit is the smallest and the energy transfer efficiency is the highest.

[0021] A4. The transmitting coil generates an alternating magnetic field under the excitation of the alternating current. According to Faraday's law of electromagnetic induction, calculate the electromotive force induced in the receiving coil. The calculation formula is as follows: , where N is the number of turns of the receiving coil, is the magnetic flux, e is the electromotive force, is the magnetic flux change amount of, is the time change amount; A5. The alternating current induced in the receiving coil supplies power to the load after passing through the secondary compensation network. Calculate the power on the load. The calculation formula is as follows: , where P is the power, U is the effective value of the voltage across the load, and is the resistance value of the load.

[0022] The data communication module is used to realize data communication between the primary side and the secondary side, ensuring the coordinated operation of the energy transfer module and the foreign object detection module; the data communication module includes an MCU, a primary data transceiver circuit, and a secondary data transceiver circuit. The MCU is electrically connected to the primary data transceiver circuit and the secondary data transceiver circuit respectively. The primary data transceiver circuit and the secondary data transceiver circuit are located on both sides of the power coil. Through the MCU, the coordinated operation of each module is carried out. The primary data transceiver circuit is used to send the data information on the primary side to the secondary side, and at the same time receive the data information feedback from the secondary side; the secondary data transceiver circuit is used to cooperate with the primary data transceiver circuit to complete the two-way communication of data, receive the data sent by the primary side and perform decoding processing, and at the same time feedback the information on the secondary side to the primary side.

[0023] As Figure 3 shown, the process of the primary data transceiver circuit transmitting data to the secondary data transceiver circuit is as follows: B1. The MCU encodes the data to be sent and then modulates it through the primary data transceiver circuit; The formula for modulation by the primary-side data transceiver circuit is as follows: , where is the modulated signal, is the modulation index, is the baseband signal, is the amplitude of the carrier voltage, is the angular frequency.

[0024] B2. The modulated signal is transmitted through the transmitting coil. After the receiving coil of the secondary-side data transceiver circuit receives the signal, it performs amplification and filtering processing; B3. The secondary-side data transceiver circuit demodulates the received signal to recover the original data signal, and then sends a handshake signal to the primary side. The primary side determines whether it has received the handshake signal. If it has received it, power transmission is performed. If the handshake signal has not been received, it continues to wait.

[0025] The principle of the secondary-side data transceiver circuit transmitting data to the primary-side data transceiver circuit is the same as that of the primary-side data transceiver circuit transmitting data to the secondary-side data transceiver circuit, and will not be repeated here.

[0026] The foreign object detection module is used to detect whether there are metal foreign objects in the high-power wireless energy transmission area to ensure the safe operation of the system. The foreign object detection module includes a control switch, a foreign object detection circuit, and a signal detection coil for decoupling from the power coil. One end of the control switch is connected to one end of the signal detection coil, and the other end of the signal detection coil is respectively connected to one end of the foreign object detection circuit and one end of the primary-side data transceiver circuit. The other end of the foreign object detection circuit and the other end of the primary-side data transceiver circuit are respectively connected to the other two ends of the control switch.

[0027] The process of the foreign object detection circuit for foreign object detection is as follows: C1. After the foreign object detection circuit is powered on, it confirms the magnetic flux of the signal detection coil and performs foreign object detection through the signal detection coil; C2. When a metal foreign object enters the vicinity of the power coil, the magnetic flux of the signal detection coil changes, and the changed magnetic flux is , where is the change in magnetic flux caused by the foreign object, is the changed magnetic flux; C3. Calculate the induced voltage generated in the signal detection coil according to the changed magnetic flux. The calculation formula is as follows: , where is the calculated induced voltage, is the number of turns of the signal detection coil, is the change in magnetic flux of the signal detection coil is the time variation; C4. Amplify the calculated induced voltage; C5. Filter the amplified voltage value; C6. Sample the filtered voltage value through an AD converter to convert the continuous analog signal into a discrete voltage value sequence; C7. After the MCU receives the digital signal output by the AD converter, calculate the characteristic parameters. The calculation formula for the characteristic parameters is as follows: , where A is the characteristic parameter value, M is the total number of samples, and x(n) is the input characteristic data; C8. Compare the calculated characteristic parameter with a preset threshold. If the characteristic parameter exceeds the preset threshold, it is determined that there is a foreign object, and corresponding measures are taken according to the system settings. The corresponding measures include stopping energy transmission and issuing an alarm to prevent the foreign object from damaging the system. If the characteristic parameter does not exceed the preset threshold, it is determined that there is no foreign object, and the control switch is controlled to connect the primary data transceiver circuit to the signal detection coil, and enter the data communication and power transmission process to ensure the normal operation of the system.

[0028] Through the reasonable layout of the signal detection coil and the power coil in space, it can not only sense the magnetic field change caused by metal foreign objects, but also minimize the interference of the strong magnetic field of the power coil on it, achieving the effect of coil multiplexing, enabling more detection coils to be arranged in a limited space, thereby expanding the detection range and ensuring the comprehensiveness of foreign object detection in the wireless charging area. For example, place the detection coil near the power coil but not coincident with it, and realize a certain degree of decoupling by optimizing parameters such as the geometric shape, size, and relative position of the coil, so as to use this coil for foreign object detection without affecting power transmission; In the system startup or initialization stage, the MCU first controls the control switch to connect the signal detection coil to the foreign object detection circuit for foreign object detection. If a foreign object is detected, operate according to the processing method in the above foreign object detection process; if no foreign object is detected, the MCU controls the control switch to switch the coil to the data sending circuit for data communication between the primary and secondary sides, such as sending control instructions, status information, etc.; After completing the data communication, or during the power transmission process, the MCU will control the control switch at regular time intervals or according to the system-set conditions to connect the coil to the foreign object detection circuit for periodic foreign object detection to monitor in real time whether a foreign object enters the vicinity of the power coil and ensure the safety of the system during the entire operation process.

[0029] Based on the above-described foreign object detection device for high-power wireless energy based on signal coil multiplexing, the present invention also provides a foreign object detection method for high-power wireless energy based on signal coil multiplexing, as Figure 4 shown, which includes the following steps: S1. The MCU controls the control switch to connect the signal detection coil to the foreign object detection circuit, so that the signal detection coil is in a state of ready to detect foreign objects; S2. Determine whether there is a foreign object. If there is a foreign object, the MCU controls to maintain the foreign object detection state. If there is no foreign object, then enter S3; in the foreign object detection state, continuously monitor whether there is an abnormality during the working process. If there is an abnormality, turn off the device; S3. The MCU controls the control switch to connect the primary data transceiver circuit to the signal detection coil; S4. The secondary data transceiver circuit receives and decodes the data, and at the same time sends a handshake signal to the primary side; S5. Confirm whether the primary side has received the handshake signal sent by the secondary side. If the handshake signal is not received, the MCU controls to maintain the foreign object detection state; if the handshake signal is received, then perform power transmission; S6. The signal detection coil on the secondary side is connected to the foreign object detection circuit to determine whether there is a foreign object. If there is a foreign object, the MCU controls the energy transmission module to stop power transmission. If there is no foreign object, the MCU controls the control switch to connect the secondary data transceiver circuit to the signal detection coil; S7. The primary side receives and decodes the data, and at the same time sends a handshake signal to the secondary side; S8. Confirm whether the secondary side has received the handshake signal sent by the primary side. If the handshake signal is received, then perform power transmission, and return to S6. If the handshake signal is not received, the MCU controls the energy transmission module to stop power transmission.

[0030] In summary, the signal coil is used as the detection coil for foreign object detection. Through a polling method with timing control, it is periodically detected whether there is a metal foreign object on the transmitting coil. If there is a foreign object, foreign object detection is continuously performed and no switching to data transmission is made. If there is no foreign object, circuit switching and timed data transmission are performed to determine whether there is a matching receiving coil on the secondary side. Similarly, when there is a receiving coil on the secondary side, the primary signal coil performs foreign object detection. If there is no foreign object signal coil, it switches to data transmission. After the secondary side receives the data and decodes it, it determines whether it matches. After matching, an energy demand signal is sent to the primary side, and the primary side performs wireless charging according to the secondary side's demand after receiving the signal; after the handshake is completed, the signal transmitting coil enters the foreign object detection stage again, continuously monitoring whether there is an abnormality during the working process. If there is an abnormality, turn off the device.

[0031] Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A foreign body detection device based on high-power wireless energy multiplexing of signal coils, characterized in that: It includes an energy transmission module, a data communication module and a foreign object detection module, wherein the data communication module is electrically connected to the energy transmission module and the foreign object detection module respectively, and the energy transmission module is used to realize wireless transmission of electric energy from a DC power supply to a load, thereby providing the required electric energy to the load; The data communication module is used to realize data communication between the primary side and the secondary side, ensuring the coordinated work of the energy transmission module and the foreign object detection module; the data communication module includes an MCU, a primary side data transceiver circuit and a secondary side data transceiver circuit, the MCU is electrically connected to the primary side data transceiver circuit and the secondary side data transceiver circuit respectively, and the primary side data transceiver circuit and the secondary side data transceiver circuit are respectively located on both sides of the power coil; The foreign object detection module is used to detect whether there is a metal foreign object in the high-power wireless energy transmission area to ensure the safe operation of the system. The foreign object detection module includes a control switch, a foreign object detection circuit and a signal detection coil for decoupling from the power coil. One end of the control switch is connected to one end of the signal detection coil, and the other end of the signal detection coil is respectively connected to one end of the foreign object detection circuit and one end of the primary data transceiver circuit. The other end of the foreign object detection circuit and the other end of the primary data transceiver circuit are respectively connected to the other two ends of the control switch.

2. According to claim 1, a foreign body detection device based on high-power wireless energy multiplexing of signal coils is characterized by: The energy transmission module includes a DC power supply, a DC-AC converter, a compensation network, a power coil and a load, wherein the DC power supply is connected to the input end of the DC-AC converter, the power coil includes a transmitting coil and a receiving coil, the compensation network is connected to the transmitting coil and the receiving coil, and the receiving coil and the transmitting coil are both connected to the compensation network, the load is located at the other end of the compensation network at the receiving coil, and the DC-AC converter is located at the other end of the compensation network at the transmitting coil.

3. According to claim 2, a foreign body detection device based on high-power wireless energy multiplexing of signal coils is characterized in that: The process of wireless energy transmission by the energy transmission module is as follows: A1. Directly provide DC voltage to the DC-AC converter through a DC power supply; A2, DC-AC converter converts DC power into AC power according to the control signal of MCU; A3. After the AC voltage passes through the compensation network, the transmitting coil and the receiving coil reach a resonant state; A4. The transmitting coil generates an alternating magnetic field under the excitation of alternating current. According to Faraday's law of electromagnetic induction, the electromotive force induced in the receiving coil is calculated as follows: , where N is the number of turns of the receiving coil, is the magnetic flux, e is the electromotive force, is the magnetic flux The amount of change, is the time variation; A5. The AC power induced by the receiving coil is used to supply power to the load after passing through the secondary compensation network. The power on the load is calculated using the following formula: , where P is power, U is the effective value of the voltage across the load, and is the resistance value of the load.

4. According to claim 3, a foreign body detection device based on high-power wireless energy multiplexing of signal coils is characterized in that: In step A3, the compensation network performs power compensation by connecting a capacitor in series with the transmitting coil and the receiving coil. The calculation formula of the resonant frequency during power compensation is as follows: ,in, is the resonant frequency, L is the inductance of the coil, and C is the capacitance of the series capacitor. In the resonant state, the impedance of the circuit is the smallest and the energy transfer efficiency is the highest.

5. According to claim 4, a foreign body detection device based on high-power wireless energy multiplexing of signal coils is characterized in that: The process of the primary side data transceiver circuit transmitting data to the secondary side data transceiver circuit is as follows: B1, MCU encodes the data to be sent, and then modulates it through the primary data transceiver circuit; B2. The modulated signal is transmitted through the transmitting coil, and the receiving coil of the secondary data transceiver circuit receives the signal and performs amplification and filtering. B3. The secondary side data transceiver circuit demodulates the received signal, restores the original data signal, and then sends a handshake signal to the primary side. The primary side determines whether the handshake signal is received. If it is received, power transmission is performed. If not, the handshake signal continues to wait.

6. The foreign body detection device based on high-power wireless energy multiplexing of signal coils according to claim 5 is characterized in that: In step B1, the modulation formula of the primary data transceiver circuit is: ,in, is the modulated signal, To adjust the system, is the baseband signal, is the carrier voltage amplitude, is the angular frequency.

7. The foreign body detection device based on high-power wireless energy multiplexing of signal coils according to claim 6 is characterized by: The process of the foreign body detection circuit for performing foreign body detection is as follows: C1. After the foreign body detection circuit is powered on, confirm the magnetic flux of the signal detection coil , foreign body detection is performed through the signal detection coil; C2. When a metal foreign body enters the vicinity of the power coil, the magnetic flux of the signal detection coil changes. The changed magnetic flux is ,in, is the change in magnetic flux caused by foreign matter, is the magnetic flux after the change; C3. Calculate the induced voltage generated in the signal detection coil according to the changed magnetic flux. The calculation formula is as follows: ,in, is the calculated induced voltage, is the number of turns of the signal detection coil, is the change in magnetic flux of the signal detection coil, is the time variation; C4, amplifying the calculated induced voltage; C5, filtering the amplified voltage value; C6, sampling the filtered voltage value through an AD converter to convert the continuous analog signal into a discrete voltage value sequence; C7. After receiving the digital signal output by the AD converter, the MCU calculates the characteristic parameters. The calculation formula of the characteristic parameters is as follows: , where A is the characteristic parameter value, M is the total number of samples, and x(n) is the input characteristic data; C8. Compare the calculated characteristic parameters with the preset threshold value. If the characteristic parameters exceed the preset threshold value, it is determined that there is a foreign object, and corresponding measures are taken according to the system settings. If the characteristic parameters do not exceed the preset threshold value, it is determined that there is no foreign object, and the control switch is controlled to connect the primary data transceiver circuit to the signal detection coil, entering the data communication and power transmission process.

8. The foreign body detection device based on high-power wireless energy multiplexing of signal coils according to claim 7 is characterized in that: In step C4, the formula for the amplification process is as follows: ,in, is the amplified voltage, is the feedback resistor, is the input resistance, is the induced voltage.

9. The foreign body detection device based on high-power wireless energy multiplexing of signal coils according to claim 8, characterized in that: In step C5, the filtering process formula is as follows: ,in, is the filter coefficient, is the current induced voltage input value, is the induced voltage input value at the previous moment, is the time, is the output value after filtering.

10. A foreign object detection method based on high-power wireless energy reused by signal coils, based on a foreign object detection device based on high-power wireless energy reused by signal coils as claimed in any one of claims 1 to 9, characterized in that: The steps include: S1, MCU controls the control switch to connect the signal detection coil to the foreign object detection circuit, so that the signal detection coil is in a state ready to detect foreign objects; S2: Determine whether there is a foreign object. If there is a foreign object, the MCU controls to maintain the foreign object detection state. If there is no foreign object, it enters S3. In the foreign object detection state, the working process is continuously monitored for abnormalities. If abnormal, the device is shut down. S3, MCU controls the control switch to connect the primary data transceiver circuit to the signal detection coil; S4, the secondary side data transceiver circuit receives and decodes the data, and sends a handshake signal to the primary side; S5. Confirm whether the primary side receives the handshake signal sent by the secondary side. If the handshake signal is not received, the MCU controls to maintain the foreign object detection state; if the handshake signal is received, power transmission is performed; S6, the signal detection coil on the secondary side is connected to the foreign object detection circuit to determine whether there is a foreign object. If there is a foreign object, the MCU controls the energy transmission module to stop power transmission. If there is no foreign object, the MCU controls the control switch to connect the secondary side data transceiver circuit to the signal detection coil; S7, the primary side receives and decodes the data, and sends a handshake signal to the secondary side; 、 S8. Confirm whether the secondary side receives the handshake signal sent by the primary side. If the handshake signal is received, power transmission is performed and the process returns to S6. If the handshake signal is not received, the MCU controls the energy transmission module to stop power transmission.

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