A half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply

Abstract

The present invention relates to the technical field of wireless charging power supply, and in particular to a half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply, which includes a transmitting end circuit and a receiving end circuit, wherein the transmitting end circuit includes an EMI filter circuit, a first rectifier filter circuit, a half-bridge LCC resonant inverter circuit, a first auxiliary power supply, a first signal conditioning circuit, a control circuit and a first communication circuit; the receiving end circuit mainly includes a parallel resonant circuit, a second rectifier filter circuit, a second auxiliary power supply, a second signal conditioning circuit and a second communication circuit. The present invention combines the inverter topology with the resonant topology to achieve input power regulation and reduce the size and weight of the transmitting end; wireless communication between the transmitting end and the receiving end circuit is achieved through the first communication circuit and the second communication circuit, while improving the dynamic and static performance of the power supply, ensuring that the receiving end circuit has the advantages of small size and simple structure, and has good market application value.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless charging power supplies, and in particular to a half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply. Background Art

[0002] Wireless charging technology (WCT), also known as wireless power transfer (WPT), refers to the wireless transmission of electric energy without traditional wire connection, but using conductive media such as electric field, magnetic field, microwave or laser. Its non-contact charging features no wire restriction, no plugging and unplugging, and less danger. Wireless charging is an important way to achieve convenient and efficient use of energy. It has broad application prospects in special fields such as electric vehicle charging, aerospace power supply, portable mobile device charging, medical equipment charging, coal mining and oil field mining, energy chemical industry, and underwater operations.

[0003] Wireless charging technology can be mainly divided into four types: electromagnetic induction, magnetic coupling resonance, electric field coupling, and radio wave. Among them, magnetic coupling resonance wireless charging has become the main research direction in the field of wireless charging due to its advantages such as long transmission distance, high transmission power, low dependence on medium, and strong penetration. Its basic principle is that under the excitation of high-frequency alternating current of a certain frequency, the transmitting coil and the capacitor resonate to generate an alternating near magnetic field. Through electromagnetic coupling resonance, the receiving coil and the capacitor convert magnetic energy into electrical energy and output it to the subsequent load, thereby completing energy exchange.

[0004] The magnetically coupled resonant wireless charging power supply circuit can be divided into the transmitter circuit and the receiver circuit. The transmitter inverter circuit is an important component of the magnetically coupled resonant wireless charging power supply. Its function is to convert DC power into high-frequency AC power required for the operation of the resonant coil. The inverter circuits commonly used in wireless charging systems mainly include class E inverter circuits, class D inverter circuits, half-bridge inverter circuits, and full-bridge inverter circuits. Medium and high power inverter circuits mostly use half-bridge inverters and full-bridge inverter circuits. Compared with half-bridge inverters, the two have the advantages of fewer components and simpler control.

[0005] The key to efficient transmission of magnetically coupled resonant wireless charging power is that the system works in a resonant state. For the designed coil resonator, the frequency between the power supply and the resonator must be consistent. There are four common resonant topologies: series resonance at the transmitter and series resonance at the receiver (SS); series resonance at the transmitter and parallel resonance at the receiver (SP); parallel resonance at the transmitter and series resonance at the receiver (PS); parallel resonance at the transmitter and parallel resonance at the receiver (PP).

[0006] At present, the resonant topology and half-bridge inverter topology of magnetically coupled resonant wireless charging power supplies are separated and independent from each other, requiring large-capacity resonant capacitors, which increase the size and weight of the power supply, hindering the application and promotion of half-bridge inverters in wireless charging power supplies. In terms of power output regulation, existing wireless charging power supplies mostly add DC-DC converters to the receiving circuit to control the charging voltage. When the power level increases, the size of the receiving circuit increases sharply due to the presence of inductors and capacitors, which conflicts with the demand for miniaturization of receiving equipment. Summary of the invention

[0007] In view of the problems of the prior art, the present invention provides a half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply, combines the inverter topology with the resonant topology, proposes a transmitting end half-bridge LCC resonant inverter topology, uses a symmetrical voltage-equalizing capacitor as a resonant capacitor, controls the resonant voltage and current by adjusting the duty cycle, frequency, etc., thereby realizing the adjustment of the input power and reducing the volume and weight of the transmitting end; wireless communication between the transmitting end and the receiving end circuit is realized through a first communication circuit and a second communication circuit, the second communication circuit transmits the output voltage and current data of the receiving end circuit to the first communication circuit, and the first communication circuit transmits the data to the transmitting end main control chip for processing, thereby realizing closed-loop control of the receiving end output current, while improving the dynamic and static performance of the power supply, ensuring that the receiving end circuit has the advantages of small size and simple structure, and has good market application value.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] A half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply provided by the present invention comprises a transmitting end circuit and a receiving end circuit, wherein the transmitting end circuit comprises an EMI filter circuit, a first rectifying filter circuit, a half-bridge LCC resonant inverter circuit, a first auxiliary power supply, a first signal conditioning circuit, a control circuit and a first communication circuit; the receiving end circuit mainly comprises a parallel resonant circuit, a second rectifying filter circuit, a second auxiliary power supply, a second signal conditioning circuit and a second communication circuit;

[0010] The input end of the EMI filter circuit is connected to the power grid to filter out the common mode and differential mode interference of the power grid voltage and suppress the electromagnetic interference emitted by the power supply;

[0011] The input end of the first rectifier filter circuit is connected to the output end of the EMI filter circuit, and is used to convert the input AC grid voltage into a stable DC voltage;

[0012] The input end of the half-bridge LCC resonant inverter circuit is connected to the output end of the first rectifier filter circuit, and is used to invert the DC voltage into a high-frequency AC voltage, excite the resonant coil and the resonant capacitor, and generate a strong coupling magnetic field;

[0013] The parallel resonant circuit is used to generate an AC voltage for inputting a receiving loop by generating electromagnetic coupling resonance with a strong coupling magnetic field;

[0014] The input end of the second rectifying and filtering circuit is connected to the parallel resonant circuit, which is used to convert the input AC voltage into a DC voltage and output it to the load;

[0015] The first auxiliary power supply and the second auxiliary power supply are used to supply power to the transmitting end circuit and the receiving end circuit respectively;

[0016] The first communication circuit transmits the control signal of the transmitting end to the receiving end, and the second communication circuit is used to transmit the voltage and current data of the receiving end to the transmitting end;

[0017] The first signal conditioning circuit and the second signal conditioning circuit are used to sample and process the voltage and current signals of the transmitting end and the receiving end respectively.

[0018] Among them, the half-bridge LCC resonant inverter circuit includes a first capacitor CP1, a second capacitor CP2, a first switch tube VT1, a second switch tube VT2 and a transmitting coil LP, one end of the first capacitor CP1 is connected to the collector of the first switch tube VT1, the other end of the first capacitor CP1 is connected to one end of the second capacitor CP2, the emitter of the first switch tube VT1 is connected to the collector of the second switch tube VT2, the other end of the second capacitor CP2 is connected to the emitter of the second switch tube VT2, and the transmitting coil LP is connected between the other end of the first capacitor CP1 and the emitter of the first switch tube VT1.

[0019] Among them, the first communication circuit includes a first communication chip PIC16F1828 and a first 2.4G communication module JF24D, and pins 13, 10, 11, 9, 12 and 17 of the first communication chip PIC16F1828 are respectively connected to pins 2, 3, 4, 5, 6 and 8 of the first 2.4G communication module JF24D, pin 1 of the first 2.4G communication module JF24D is connected to a 3.3V first auxiliary power supply, and pin 10 of the first 2.4G communication module JF24D is grounded.

[0020] Among them, the second wireless communication circuit includes a second communication chip PIC16F1828 and a second 2.4G communication module JF24D, and pins 13, 10, 11, 9, 12 and 17 of the second communication chip PIC16F1828 are respectively connected to pins 2, 3, 4, 5, 6 and 8 of the second 2.4G communication module JF24D, and pin 1 of the second 2.4G communication module JF24D is connected to a 3.3V second auxiliary power supply, and pin 10 is grounded.

[0021] The parallel resonant circuit includes a receiving coil LS and a third capacitor CS; the receiving coil LS and the third capacitor CS are connected in parallel.

[0022] The first rectifying and filtering circuit includes a rectifier bridge VD1, a first filtering inductor L1 and a first filtering capacitor C1. The output end of the rectifier bridge VD1 is connected to a first post-stage LC filter. The first post-stage LC filter is formed by connecting the first filtering inductor L1 and the first filtering capacitor C1 in series.

[0023] The second rectifying and filtering circuit includes a rectifying bridge VD2, a second filtering inductor L2 and a second filtering capacitor C2, the output end of the rectifying bridge VD2 is connected to a second post-stage LC filter, and the second post-stage LC filter is formed by connecting the second filtering inductor L2 and the second filtering capacitor C2 in series.

[0024] The present invention combines the inverter topology with the resonant topology, and proposes a transmitting end half-bridge LCC resonant inverter topology. The symmetrical voltage-equalizing capacitor is used as the resonant capacitor, and the resonant voltage and current are controlled by adjusting the duty cycle, frequency, etc., so as to adjust the input power and reduce the volume and weight of the transmitting end. The wireless communication between the transmitting end and the receiving end circuit is realized by the first communication circuit and the second communication circuit. The second communication circuit transmits the output voltage and current data of the receiving end circuit to the first communication circuit, and the first communication circuit transmits the data to the transmitting end main control chip for processing, so as to realize the closed-loop control of the receiving end output current. While improving the dynamic and static performance of the power supply, it is ensured that the receiving end circuit has the advantages of small size and simple structure, and has good market application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The schematic diagram of the half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply of the present invention is shown in FIG.

[0026] Figure 2 It is a circuit diagram of the first rectifying and filtering circuit, the half-bridge LCC resonant inverter circuit, the parallel resonant circuit and the second rectifying and filtering circuit of the present invention.

[0027] Figure 3 1 is a circuit diagram of a first communication circuit and a second communication circuit of the present invention.

[0028] Figure 4 It is a circuit diagram of a half-bridge LCC resonant inverter circuit of the present invention. DETAILED DESCRIPTION

[0029] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with the embodiments and drawings, and the contents mentioned in the embodiments are not intended to limit the present invention. The present invention is described in detail below in conjunction with the drawings.

[0030] A half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply, such as Figures 1 to 4 As shown, it includes a transmitting circuit and a receiving circuit, the transmitting circuit includes an EMI filter circuit, a first rectifier filter circuit, a half-bridge LCC resonant inverter circuit, a first auxiliary power supply, a first signal conditioning circuit, a control circuit and a first communication circuit; the receiving circuit mainly includes a parallel resonant circuit, a second rectifier filter circuit, a second auxiliary power supply, a second signal conditioning circuit and a second communication circuit;

[0031] The input end of the EMI filter circuit is connected to the power grid to filter out the common mode and differential mode interference of the power grid voltage and suppress the electromagnetic interference emitted by the power supply;

[0032] The input end of the first rectifier filter circuit is connected to the output end of the EMI filter circuit, and is used to convert the input AC grid voltage into a stable DC voltage;

[0033] The input end of the half-bridge LCC resonant inverter circuit is connected to the output end of the first rectifier filter circuit, and is used to invert the DC voltage into a high-frequency AC voltage, excite the resonant coil and the resonant capacitor, and generate a strong coupling magnetic field;

[0034] The parallel resonant circuit is used to generate an AC voltage for inputting a receiving loop by generating electromagnetic coupling resonance with a strong coupling magnetic field;

[0035] The input end of the second rectifying and filtering circuit is connected to the parallel resonant circuit, which is used to convert the input AC voltage into a DC voltage and output it to the load;

[0036] The first auxiliary power supply and the second auxiliary power supply are used to supply power to the transmitting end circuit and the receiving end circuit respectively;

[0037] The first communication circuit transmits the control signal of the transmitting end to the receiving end, and the second communication circuit is used to transmit the voltage and current data of the receiving end to the transmitting end;

[0038] The first signal conditioning circuit and the second signal conditioning circuit are used to sample and process the voltage and current signals of the transmitting end and the receiving end respectively.

[0039] The control circuit is used to control the operation of the entire charging power supply, including signal processing, protection warning, power regulation, etc.

[0040] Specifically, the present invention combines the inverter topology with the resonant topology, and proposes a transmitting end half-bridge LCC resonant inverter topology, in which the symmetrical voltage-equalizing capacitor is used as the resonant capacitor, and the resonant voltage and current are controlled by adjusting the duty cycle, frequency, etc., so as to adjust the input power and reduce the volume and weight of the transmitting end; wireless communication between the transmitting end and the receiving end circuit is realized through the first communication circuit and the second communication circuit, and the second communication circuit transmits the output voltage and current data of the receiving end circuit to the first communication circuit, and the first communication circuit transmits the data to the transmitting end main control chip for processing, so as to realize closed-loop control of the receiving end output current, and improve the dynamic and static performance of the power supply while ensuring that the receiving end circuit has the advantages of small size and simple structure, and has good market application value.

[0041] The present embodiment describes a half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply, wherein the half-bridge LCC resonant inverter circuit includes a first capacitor CP1, a second capacitor CP2, a first switch tube VT1, a second switch tube VT2 and a transmitting coil LP, wherein one end of the first capacitor CP1 is connected to the collector of the first switch tube VT1, the other end of the first capacitor CP1 is connected to one end of the second capacitor CP2, the emitter of the first switch tube VT1 is connected to the collector of the second switch tube VT2, the other end of the second capacitor CP2 is connected to the emitter of the second switch tube VT2, and the transmitting coil LP is connected between the other end of the first capacitor CP1 and the emitter of the first switch tube VT1.

[0042] In the half-bridge resonant inverter magnetically coupled resonant wireless charging power supply described in this embodiment, the first communication circuit includes a first communication chip PIC16F1828 and a first 2.4G communication module JF24D, and the 13th pin, 10th pin, 11th pin, 9th pin, 12th pin and 17th pin of the first communication chip PIC16F1828 are respectively connected to the 2nd pin, 3rd pin, 4th pin, 5th pin, 6th pin and 8th pin of the first 2.4G communication module JF24D, the 1st pin of the first 2.4G communication module JF24D is connected to the 3.3V first auxiliary power supply, and the 10th pin of the first 2.4G communication module JF24D is grounded.

[0043] In the present embodiment, a half-bridge resonant inverter magnetically coupled resonant wireless charging power supply is described, wherein the second wireless communication circuit includes a second communication chip PIC16F1828 and a second 2.4G communication module JF24D, and pins 13, 10, 11, 9, 12 and 17 of the second communication chip PIC16F1828 are respectively connected to pins 2, 3, 4, 5, 6 and 8 of the second 2.4G communication module JF24D, and pin 1 of the second 2.4G communication module JF24D is connected to a 3.3V second auxiliary power supply, and pin 10 is grounded.

[0044] In the half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply described in this embodiment, the parallel resonant circuit includes a receiving coil LS and a third capacitor CS; the receiving coil LS and the third capacitor CS are connected in parallel.

[0045] In the half-bridge resonant inverter magnetically coupled resonant wireless charging power supply described in this embodiment, the first rectifier and filter circuit includes a rectifier bridge VD1, a first filter inductor L1 and a first filter capacitor C1, and the output end of the rectifier bridge VD1 is connected to a first post-stage LC filter, and the first post-stage LC filter is formed by connecting the first filter inductor L1 and the first filter capacitor C1 in series.

[0046] In the half-bridge resonant inverter magnetically coupled resonant wireless charging power supply described in this embodiment, the second rectifier and filter circuit includes a rectifier bridge VD2, a second filter inductor L2 and a second filter capacitor C2, and the output end of the rectifier bridge VD2 is connected to a second post-stage LC filter, and the second post-stage LC filter is formed by connecting the second filter inductor L2 and the second filter capacitor C2 in series.

[0047] The basic working principle of the present invention is as follows:

[0048] The grid inputs 220V AC power to the transmitting circuit, which first passes through the first rectification and filtering circuit to output a stable DC voltage, and then is converted into a high-frequency AC voltage through a half-bridge LCC resonant inverter circuit to generate a resonant voltage and a resonant current, thereby generating a strong coupling magnetic field in the near field of the transmitting coil; the parallel resonant circuit of the receiving circuit generates a receiving loop input voltage through electromagnetic coupling resonance, and the input AC voltage passes through the second rectification and filtering circuit to output a DC voltage to the load.

[0049] In order to facilitate the working mode analysis of the half-bridge LCC resonant inverter circuit, the front-stage AC-DC rectifier filter circuit is idealized as a 310V DC voltage source, and the load of the receiving circuit is reflected to the transmitting circuit, which can be obtained as follows: Figure 4 The simplified structure diagram of the half-bridge resonant inverter circuit shown includes a 310V DC power supply Vg, a first switch tube VT1, a second switch tube VT2, a first capacitor CP1, a second capacitor CP2, a transmitting coil LP and a reflected impedance Zref.

[0050] According to the on-off status of the switch tube and the current loop state, it can be divided into six modes.

[0051] Mode 1: The first switch tube VT1 is turned on, and the second switch tube VT2 is turned off. The current loop is: Vg→VT1→LP+Zref→CP2→Vg and Vg→CP1→CP2→Vg;

[0052] Mode 2: the first switch tube VT1 is turned off, the second switch tube VT2 is turned off, and the parasitic diode of the second switch tube VT2 continues current until the resonant circuit current is reduced to 0;

[0053] Mode 3: The first switch tube VT1 is turned off, and the second switch tube VT2 is turned off, immediately following mode 2, and the circuit is open and there is no current;

[0054] Mode 4: The first switch tube VT1 is turned off, and the second switch tube VT2 is turned on. The current loop is: Vg→CP1→LP+Zref→VT2→Vg and Vg→CP1→CP2→Vg;

[0055] Mode 5: the first switch tube VT1 is turned off, the second switch tube VT2 is turned off, and the parasitic diode of the first switch tube VT1 continues current until the resonant circuit current is reduced to 0;

[0056] Mode 6: The first switch tube VT1 is turned off, and the second switch tube VT2 is turned off, immediately following mode 5, and the circuit is open and there is no current.

[0057] It can be seen that the working states of modes 1, 2, 3 and modes 4, 5, 6 are similar, and the working process of the half-bridge resonant inverter circuit has a symmetry similar to that of the full-bridge inverter. The inverter circuit drives the square wave with complementary center symmetry. If the duty cycle D=0.5, the working process of the inverter circuit only has completely symmetrical modes 1 and 4, which can be equivalent to a square wave power supply uH.

[0058] The first capacitor and the second capacitor have the same value, that is, the resonant capacitor is CP1=CP2=CP0, then the total impedance of the LCC series-parallel resonant circuit is:

[0059]

[0060] Let the numerator and denominator of Im(Zp) be equal to zero, and we can get:

[0061] The numerator is zero:

[0062] The denominator is zero:

[0063] When the inverter square wave angular frequency w=w1, the circuit undergoes series resonance, and the inverter square wave power source excites the coil LP to generate a resonant current. Therefore, w1 is selected as the resonant angular frequency of the inverter circuit.

[0064] Let CP = 2CP0, then the half-bridge LCC resonant inverter circuit can be equivalent to a series resonant equivalent circuit. In order to ensure that the wireless charging system works in a magnetic resonance state, the resonant frequency of the transceiver coil needs to remain consistent, so there is

[0065]

[0066] Compared with other wireless communication methods, 2.4GHz wireless communication has obvious advantages such as low power consumption, low cost and small size. Therefore, based on the 2.4GHz wireless transceiver module JF24D, two-way communication is established between the transmitter and the receiver of wireless charging, such as Figure 3 The basic working process is as follows:

[0067] The second communication circuit transmits the output voltage and current data of the receiving end circuit to the first communication circuit, and the first communication circuit then transmits the data to the transmitting end control circuit for processing, thereby realizing closed-loop control of the receiving end output current, improving the dynamic and static performance of the power supply, and ensuring the output of a stable charging current.

[0068] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention is disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent changes and modifications made to the above embodiments according to the technology of the present invention are within the scope of the technical solution of the present invention without departing from the content of the technical solution of the present invention.

Claims

1. A half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply, characterized in that: It includes a transmitting circuit and a receiving circuit, wherein the transmitting circuit includes an EMI filter circuit, a first rectifier filter circuit, a half-bridge LCC resonant inverter circuit, a first auxiliary power supply, a first signal conditioning circuit, a control circuit and a first communication circuit; the receiving circuit mainly includes a parallel resonant circuit, a second rectifier filter circuit, a second auxiliary power supply, a second signal conditioning circuit and a second communication circuit; The input end of the EMI filter circuit is connected to the power grid to filter out the common mode and differential mode interference of the power grid voltage and suppress the electromagnetic interference emitted by the power supply; The input end of the first rectifier filter circuit is connected to the output end of the EMI filter circuit, and is used to convert the input AC grid voltage into a stable DC voltage; The input end of the half-bridge LCC resonant inverter circuit is connected to the output end of the first rectifier filter circuit, and is used to invert the DC voltage into a high-frequency AC voltage to stimulate the generation of a strong coupling magnetic field; The parallel resonant circuit is used to generate an AC voltage for inputting a receiving loop by electromagnetic coupling resonance with a strong coupling magnetic field; The input end of the second rectifying and filtering circuit is connected to the parallel resonant circuit, which is used to convert the input AC voltage into a DC voltage and output it to the load; The first auxiliary power supply and the second auxiliary power supply are used to supply power to the transmitting end circuit and the receiving end circuit respectively; The first communication circuit transmits the control signal of the transmitting end to the receiving end, and the second communication circuit is used to transmit the voltage and current data of the receiving end to the transmitting end; The first signal conditioning circuit and the second signal conditioning circuit are used to sample and process the voltage and current signals of the transmitting end and the receiving end respectively; The half-bridge LCC resonant inverter circuit includes a first capacitor CP1, a second capacitor CP2, a first switch tube VT1, a second switch tube VT2 and a transmitting coil LP, one end of the first capacitor CP1 is connected to the collector of the first switch tube VT1, the other end of the first capacitor CP1 is connected to one end of the second capacitor CP2, the emitter of the first switch tube VT1 is connected to the collector of the second switch tube VT2, the other end of the second capacitor CP2 is connected to the emitter of the second switch tube VT2, and the transmitting coil LP is connected between the other end of the first capacitor CP1 and the emitter of the first switch tube VT1; The first communication circuit includes a first communication chip PIC16F1828 and a first 2.4G communication module JF24D, wherein pins 13, 10, 11, 9, 12 and 17 of the first communication chip PIC16F1828 are respectively connected to pins 2, 3, 4, 5, 6 and 8 of the first 2.4G communication module JF24D, pin 1 of the first 2.4G communication module JF24D is connected to a first auxiliary power supply, and pin 10 of the first 2.4G communication module JF24D is grounded; The second communication circuit includes a second communication chip PIC16F1828 and a second 2.4G communication module JF24D, and the 13th pin, the 10th pin, the 11th pin, the 9th pin, the 12th pin and the 17th pin of the second communication chip PIC16F1828 are respectively connected to the 2nd pin, the 3rd pin, the 4th pin, the 5th pin, the 6th pin and the 8th pin of the second 2.4G communication module JF24D, and the 1st pin of the second 2.4G communication module JF24D is connected to the second auxiliary power supply, and the 10th pin is grounded; The parallel resonant circuit comprises a receiving coil LS and a third capacitor CS; the receiving coil LS and the third capacitor CS are connected in parallel; The grid inputs 220V AC power to the transmitting circuit, which first passes through the first rectifier and filter circuit to output a stable DC voltage, and then is converted into a high-frequency AC voltage through a half-bridge LCC resonant inverter circuit to generate a resonant voltage and a resonant current, thereby generating a strong coupling magnetic field in the near field of the transmitting coil; the parallel resonant circuit of the receiving circuit generates a receiving loop input voltage through electromagnetic coupling resonance, and the input AC voltage passes through the second rectifier and filter circuit to output a DC voltage to the load; The front-stage AC-DC rectifier filter circuit is idealized as a 310V DC voltage source, and the load of the receiving end circuit is reflected to the transmitting end circuit, and a simplified diagram of the half-bridge resonant inverter circuit structure is obtained, including a 310V DC power supply Vg, a first switch tube VT1, a second switch tube VT2, a first capacitor CP1, a second capacitor CP2, a transmitting coil LP and a reflected impedance Zref; According to the on-off status of the switch tube and the current loop state, it is divided into six modes: Mode 1: The first switch tube VT1 is turned on, and the second switch tube VT2 is turned off. The current loop is: Vg→VT1→LP+Zref→CP2→Vg and Vg→CP1→CP2→Vg; Mode 2: the first switch tube VT1 is turned off, the second switch tube VT2 is turned off, and the parasitic diode of the second switch tube VT2 continues current until the resonant circuit current is reduced to 0; Mode 3: The first switch tube VT1 is turned off, and the second switch tube VT2 is turned off, immediately following mode 2, and the circuit is open and there is no current; Mode 4: The first switch tube VT1 is turned off, and the second switch tube VT2 is turned on. The current loop is: Vg→CP1→LP+Zref→VT2→Vg and Vg→CP1→CP2→Vg; Mode 5: the first switch tube VT1 is turned off, the second switch tube VT2 is turned off, and the parasitic diode of the first switch tube VT1 continues current until the resonant circuit current is reduced to 0; Mode 6: The first switch tube VT1 is turned off, the second switch tube VT2 is turned off, and immediately after mode 5, the circuit is open and there is no current; It can be seen that the working states of modes 1, 2, 3 are similar to those of modes 4, 5, and 6, respectively. The working process of the half-bridge resonant inverter circuit has a symmetry similar to that of the full-bridge inverter. The inverter circuit drives the square wave with complementary symmetry at the center. If the duty cycle D=0.5, the working process of the inverter circuit only has completely symmetrical modes 1 and 4, which can be equivalent to a square wave power supply uH. The first capacitor and the second capacitor have the same value, that is, the resonant capacitor is CP1=CP2=CP0, then the total impedance of the LCC series-parallel resonant circuit is: ； Let the numerator and denominator of Im(Zp) be equal to zero, and we can get: The numerator is zero: ; The denominator is zero: ; When the inverter square wave angular frequency w=w 1, the circuit undergoes series resonance, and the inverter square wave power supply excites the coil LP to generate a resonant current; therefore, select w 1 is the resonant angular frequency of the inverter circuit; Let CP = 2CP0, then the half-bridge LCC resonant inverter circuit can be equivalent to a series resonant equivalent circuit; the resonant frequency of the transmitting and receiving coils needs to be kept consistent, then: ； Based on the 2.4GHz wireless transceiver module JF24D, two-way communication is established between the transmitter and receiver of wireless charging. The working process is as follows: The second communication circuit transmits the output voltage and current data of the receiving end circuit to the first communication circuit, and the first communication circuit then transmits the data to the transmitting end control circuit for processing, thereby realizing closed-loop control of the receiving end output current.

2. A half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply according to claim 1, characterized in that: The first rectifying and filtering circuit includes a rectifier bridge VD1, a first filtering inductor L1 and a first filtering capacitor C1. The output end of the rectifier bridge VD1 is connected to a first post-stage LC filter. The first post-stage LC filter is formed by connecting the first filtering inductor L1 and the first filtering capacitor C1 in series.

3. A half-bridge resonant inverter type magnetically coupled resonant wireless charging power supply according to claim 1, characterized in that: The second rectifying and filtering circuit includes a rectifier bridge VD2, a second filtering inductor L2 and a second filtering capacitor C2. The output end of the rectifier bridge VD2 is connected to a second post-stage LC filter. The second post-stage LC filter is formed by connecting the second filtering inductor L2 and the second filtering capacitor C2 in series.

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