Wireless charging phased constant current and constant voltage output control method adapted to offset working conditions

Abstract

The present invention provides a wireless charging staged constant current and constant voltage output control method adapted to offset working conditions. The wireless charging control method is specifically as follows: the control of the transmitting end and the receiving end is carried out synchronously, the transmitting end calculates the input impedance phase angle in real time, and records the output voltage U of the high-frequency AC power supply when the input impedance phase angle is less than the threshold value. p and output current I p The receiving end obtains the charging demand of the load and determines the charging method and the required values of charging current and voltage. It collects the charging current or charging voltage in real time and compares it with the corresponding required value. According to the comparison result, the receiving end compensation network is adjusted to adjust the charging current or charging voltage. The input impedance phase angle changes due to the adjustment of the receiving end compensation network. The transmitting end adjusts U according to the change of the input impedance phase angle. p or I p The present invention does not require estimation of the mutual inductance between the transmitting coil and the receiving coil, avoids wireless communication required for closed-loop control between the transmitting end and the receiving end, and is applicable to wireless charging in a wider range of scenarios.

Description

Technical Field

[0001] The present invention relates to the field of wireless charging control technology, and in particular to a wireless charging staged constant current and constant voltage output control method adapting to offset working conditions. Background Art

[0002] Wireless charging technology, due to its portability and safety, has been widely adopted in various technological fields, particularly in electric vehicles, where it can effectively address issues such as insufficient range and inconvenient charging. Due to the characteristics of electric vehicle batteries, the mainstream charging method is constant voltage and constant current (CC). Therefore, wireless charging requires phased constant current and constant voltage output, as well as rapid switching between these two modes. Existing technologies often achieve phased constant current and constant voltage charging of loads by controlling the duty cycle, phase shift angle, and operating frequency of the transmitter's power electronic converter. However, these methods require wireless communication to feed information from the receiver to the transmitter, achieving closed-loop control. In high-frequency electromagnetic environments, the communication equipment used in these methods cannot guarantee reliability and stability. If electromagnetic shielding is used to ensure communication stability, the magnetic permeability and unit loss of the magnetic material in the shielding device, which varies with the system's operating frequency, will affect parameters such as the coil's self-inductance and mutual inductance, further impacting system efficiency. Summary of the Invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a wireless charging staged constant current and constant voltage output control method that adapts to offset working conditions.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A wireless charging phased constant current and constant voltage output control method adapted to offset working conditions, with synchronous control of the transmitter and receiver;

[0006] The transmitter control unit calculates the input impedance phase angle in real time during the wireless charging process and collects the output voltage U of the high-frequency AC power supply corresponding to the input impedance phase angle being less than the threshold. p and output current I p ;

[0007] The receiving end control unit obtains the charging requirements of the load through the load's battery management system, and determines the charging method, as well as the required values of charging current and charging voltage based on the charging requirements;

[0008] The receiving end control unit collects the charging current and charging voltage applied to the load in real time, compares the collected charging current or charging voltage with the charging demand value, and adjusts the receiving end compensation network according to the comparison result to adjust the charging current or charging voltage of the load;

[0009] After the compensation network at the receiving end is adjusted, the input impedance phase angle changes. The transmitter control unit obtains the input impedance phase angle after the compensation network at the receiving end is adjusted. The transmitter control unit adjusts the high-frequency AC power supply according to the obtained input impedance phase angle and the corresponding charging method, and adjusts the output voltage of the high-frequency AC power supply to the output voltage U p Or adjust the output current to output current I p .

[0010] Furthermore, the charging mode includes constant current charging, constant voltage charging and constant current constant voltage charging.

[0011] Furthermore, when the charging mode is a constant current charging mode, the specific process of the corresponding wireless charging is as follows: when wireless charging starts, the high-frequency AC power supply gradually increases the output voltage, and the charging current at both ends of the receiving end load gradually increases. The receiving end control unit compares the charging current at both ends of the load with the charging current demand value in real time. When the charging current reaches the charging current demand value, the duty cycle of the two power switching tubes in the receiving end compensation network is calculated, and the two power switching tubes are controlled to be turned on and off according to the calculated duty cycle of the two power switching tubes in the receiving end compensation network, so as to maintain the charging current not exceeding the charging current demand value until charging is completed.

[0012] Furthermore, when the on and off of the two power switch tubes are controlled according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network, the input impedance phase angle is calculated in real time by the transmitting end control unit, and it is determined whether the input impedance meets the purely resistive condition. When the input impedance does not meet the purely resistive condition, the recorded output voltage U is used. p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output voltage of the high-frequency AC power supply to the output voltage U p .

[0013] Furthermore, when the charging mode is constant current and constant voltage charging, the battery management system of the load collects the load voltage in real time. When the load voltage is lower than the preset voltage, it is in the constant current charging stage. After the voltage reaches the preset voltage, the load switches from the constant current stage to the constant voltage stage to continue charging.

[0014] Furthermore, when the charging mode is constant current and constant voltage charging, and is in its constant current charging stage, the specific process of the corresponding wireless charging is: the receiving end control unit compares the charging current at both ends of the load with the charging current demand value in real time, and the receiving end control unit calculates the duty cycle of the two power switching tubes in the compensation network according to the comparison result, and controls the opening and closing of the two power switching tubes according to the calculated duty cycle of the two power switching tubes in the receiving end compensation network to maintain the charging current not exceeding the charging current demand value.

[0015] Furthermore, when the charging mode is constant current and constant voltage charging, and the charging is converted from the constant current stage to the constant voltage stage, the transmitter control unit calculates the input impedance phase angle in real time and determines whether the input impedance meets the pure resistive condition. When the input impedance does not meet the pure resistive condition, the output current I p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output current of the high-frequency AC power supply to the output current I p , the charging voltage at the receiving end reaches the required charging voltage value.

[0016] Furthermore, when the charging mode is constant voltage charging, the charging voltage requirement value of the load remains unchanged, and the charging current requirement value continues to decrease with the change of power. The corresponding specific process of wireless charging is: when wireless charging starts, the high-frequency AC power supply gradually increases the output voltage, and the receiving end control unit compares the charging current and the charging current requirement value in real time, and when the charging current increases to the charging current requirement value, calculates the duty cycle of the two power switching tubes according to the comparison result, and controls the opening and closing of the two power switching tubes according to the duty cycle of the two power switching tubes to maintain the charging current not exceeding the current charging current requirement value of the load. At the same time, the transmitting end control unit detects and calculates the transmitting end input impedance in real time. After detecting the change of the transmitting end input impedance, it calculates the output voltage U according to the recorded output voltage U. p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output voltage of the high-frequency AC power supply to the output voltage U p The receiving end control unit adjusts the two power switches in real time according to the comparison results to maintain the charging current to meet the current charging current demand value. At the same time, the transmitting end control unit calculates the input impedance phase angle in real time and determines whether the input impedance meets the pure resistive condition. When the input impedance does not meet the pure resistive condition, the output current I p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output current of the high-frequency AC power supply to the output current I p , the charging voltage at the receiving end reaches the required charging voltage value.

[0017] Furthermore, when the output current of the high frequency AC power supply is adjusted to the output current I pThe receiving end control unit also detects the charging voltage across the load in real time, compares the charging voltage with the charging voltage requirement value, and calculates the duty cycle of the two power switch tubes in the compensation network according to the comparison result, and controls the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network, maintaining the charging voltage at the charging voltage requirement value until charging is completed.

[0018] The beneficial effects of the present invention are:

[0019] There's no need to estimate the mutual inductance between the transmitting and receiving coils, eliminating the wireless communication required for closed-loop control between the transmitting and receiving ends, making it suitable for wireless charging in a wider range of scenarios. Under different charging modes, the current or voltage is ensured to meet the charging requirements of the wireless charging load by adjusting the duty cycle of the receiving compensation network and the power switch tube within the transmitting high-frequency AC power supply. Furthermore, in constant current and constant voltage charging mode, it can automatically switch from constant current output to constant voltage output based on the charging status of the load, obtain the corresponding charging requirements, and make corresponding adjustments, thus achieving automated, phased constant current and constant voltage output control. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a process of the present invention;

[0021] Figure 2 This is a schematic diagram of a wireless charging process under a constant current charging mode according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a wireless charging process under a constant voltage charging mode according to an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the change of charging voltage and charging current under a constant current and constant voltage charging mode according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of a wireless charging process under a constant current and constant voltage charging mode according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and examples. Example

[0026] A wireless charging phased constant current and constant voltage output control method adapted to offset working conditions, such as Figure 1 As shown, the control of the transmitting end and the receiving end is carried out synchronously;

[0027] The transmitter control unit calculates the input impedance phase angle in real time during the wireless charging process and collects the output voltage U of the high-frequency AC power supply corresponding to the input impedance phase angle being less than the threshold. pand output current I p ;

[0028] The receiving end control unit obtains the charging requirements of the load through the load's battery management system, and determines the charging method, as well as the required values of charging current and charging voltage based on the charging requirements;

[0029] The receiving end control unit collects the charging current and charging voltage applied to the load in real time, compares the collected charging current or charging voltage with the charging demand value, and adjusts the receiving end compensation network according to the comparison result to adjust the charging current or charging voltage of the load;

[0030] After the compensation network at the receiving end is adjusted, the input impedance phase angle changes. The transmitter control unit obtains the input impedance phase angle after the compensation network at the receiving end is adjusted. The transmitter control unit adjusts the high-frequency AC power supply according to the obtained input impedance phase angle and the corresponding charging method, and adjusts the output voltage of the high-frequency AC power supply to the output voltage U p Or adjust the output current to output current I p .

[0031] The receiving end compensation network includes a bidirectional switch and two capacitors, wherein the two capacitors are connected in series, and the bidirectional switch is connected in parallel at both ends of one of the capacitors.

[0032] When the charging mode is constant current charging, such as Figure 2 As shown, the specific process of wireless charging is as follows: wireless charging starts, the high-frequency AC power supply gradually increases the output voltage, and the charging current I b The receiving end control unit compares the charging current I at both ends of the load in real time. b The charging current demand value I r , the charging current I b Reach the charging current requirement value I r When the charging current I b Does not exceed the charging current requirement value I r At the same time, the input impedance phase angle is calculated in real time by the transmitter control unit, and whether the input impedance meets the pure resistive (ZPA) condition is judged in real time. When the input impedance does not meet the pure resistive condition, the recorded output voltage U p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output voltage of the high-frequency AC power supply to the output voltage U p , until charging is completed.

[0033] Since the charging current demand value does not change over time under the constant current charging mode, the charging current I b Equal to the charging current demand value I r The duty cycle of the two power switch tubes is used to control the opening and closing of the two power switch tubes, thereby maintaining the charging current I b Maintain the required charging current value I r purpose.

[0034] When the charging mode is constant voltage charging, Figure 3 As shown, the specific process of corresponding wireless charging is:

[0035] The receiving end control unit compares the charging current I at both ends of the load in real time b The charging current demand value I r The receiving end control unit calculates the duty cycle of the two power switch tubes in the receiving end compensation network according to the comparison result, and controls the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network to ensure the charging current I b Can meet the corresponding charging current demand value I r , and according to the recorded output voltage U p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output voltage of the high-frequency AC power supply to the output voltage U p The receiving end control unit adjusts the two power switches in real time according to the comparison results to maintain the charging current I b Does not exceed the current charging current requirement value I r At the same time, the transmitter control unit calculates the input impedance phase angle in real time and determines whether the input impedance meets the pure resistive condition. When the input impedance does not meet the pure resistive condition, the output current I p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output current of the high-frequency AC power supply to the output current I p , receiving end charging voltage U b Reach the charging voltage requirement value U r The receiving end control unit also detects the charging voltage U at both ends of the load in real time. b and the charging voltage U b and charging voltage requirement value U r Compare and calculate the duty cycle of the two power switch tubes in the receiving end compensation network according to the comparison result, and control the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network to maintain the charging voltage Ub is the charging voltage requirement value U r , until charging is completed.

[0036] When the charging mode is constant current and constant voltage charging, the load is in the constant current charging stage when the voltage is lower than the preset voltage. After the voltage reaches the preset voltage, the charging is converted from the constant current stage to the constant voltage stage. In different stages of the constant current and constant voltage charging mode, the charging voltage U b and charging current I b Changes such as Figure 4 shown.

[0037] When the charging mode is constant current constant voltage charging, such as Figure 5 As shown, the specific process of wireless charging is as follows: first, the charging is in the constant current charging stage, and the receiving end control unit compares the charging current I b and the charging current demand value I r The receiving end control unit calculates the duty cycle of the two power switch tubes in the receiving end compensation network according to the comparison result, and controls the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network to maintain the charging current I b Does not exceed the charging current requirement value I r At the same time, the input impedance phase angle is calculated in real time by the transmitter control unit, and whether the input impedance meets the pure resistive (ZPA) condition is judged in real time. When the input impedance does not meet the pure resistive condition, the recorded output voltage U p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output voltage of the high-frequency AC power supply to the output voltage U p , until charging enters the constant voltage stage.

[0038] When charging is in the constant voltage stage, the receiving end control unit still compares the charging current I b and the charging current demand value I r However, due to the charging current demand value I r The receiving end control unit is based on the comparison result and the charging current demand value I r Calculate the duty cycle of the two power switch tubes in the receiving end compensation network, and control the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network to maintain the charging current I b Does not exceed the corresponding charging current requirement value I r At the same time, the transmitter control unit continues to calculate the input impedance phase angle in real time and judges whether the input impedance meets the pure resistive condition. When the input impedance does not meet the pure resistive condition, the output current I pCalculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output current of the high-frequency AC power supply to the output current I p , receiving end charging voltage U b Reach the charging voltage requirement value U r .

[0039] When the output current of the high-frequency AC power supply is adjusted to the output current I p The receiving end control unit also detects the charging voltage U at both ends of the load in real time. b and the charging voltage U b and charging voltage requirement value U r Compare and calculate the duty cycle of the two power switch tubes in the receiving end compensation network according to the comparison result, and control the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network to maintain the charging voltage U b is the charging voltage requirement value U r , until charging is completed.

[0040] After the wireless charging system starts charging, it first adjusts the output of the receiving end compensation network and the high-frequency AC power supply to ensure the charging current I b and charging voltage U b Meet the load charging requirements, and then adjust the output of the receiving end compensation network or high-frequency AC power supply according to the charging requirements corresponding to the specific charging method, so as to achieve wireless charging under different charging methods.

[0041] And because the resistance within the wireless charging system is generally very small, when the output voltage of the high-frequency AC power supply is constant, the output of the receiving end can maintain a constant current characteristic, and when the output current of the high-frequency AC power supply is constant, the output of the receiving end is a constant current characteristic.

[0042] The receiving end compensation network and the transmitting end compensation network both contain capacitors. The calculation formula of the capacitor capacitance is as follows:

[0043]

[0044] Where: C p C is the capacitor in the transmitter compensation network. s1 、C s2 For the capacitor in the receiving end compensation network, ω is the electrical angular velocity of the entire wireless charging system, f is the switching frequency of the high-frequency AC power supply of the wireless charging system, L p is the self-inductance of the transmitting coil, L s is the self-inductance of the receiving coil.

[0045] Adjusting the duty cycle of the two power switch tubes can achieve the adjustment of the equivalent capacitance value of the receiving end compensation network, thereby achieving constant voltage or constant current charging requirements.

[0046] The wireless charging control method described in this embodiment is applied to wireless charging of electric vehicles. On the one hand, it can achieve matching between the output voltage and current of the wireless charging system and the charging demand. On the other hand, it can adapt to different charging modes and achieve fast and smooth switching between constant current output and constant voltage output.

[0047] The embodiment described above is only a preferred solution of the present invention and does not limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solution described in the claims.

Claims

1. A wireless charging phased constant current and constant voltage output control method adapted to offset working conditions, characterized in that: The control of the transmitter and receiver is synchronized; The transmitter control unit calculates the input impedance phase angle in real time during the wireless charging process and collects the output voltage U of the high-frequency AC power supply corresponding to the input impedance phase angle being less than the threshold. p and output current I p ; The receiving end control unit obtains the charging requirements of the load through the load's battery management system, and determines the charging method, as well as the required values of charging current and charging voltage based on the charging requirements; The receiving end control unit collects the charging current and charging voltage applied to the load in real time, compares the collected charging current or charging voltage with the charging demand value, and adjusts the duty cycle of the two power switches in the receiving end compensation network according to the comparison result to regulate the charging current or charging voltage of the load; The receiving end compensation network includes a bidirectional switch and two capacitors, wherein the two capacitors are connected in series and the bidirectional switch is connected in parallel across one of the capacitors; After the compensation network at the receiving end is adjusted, the input impedance phase angle changes. The transmitter control unit obtains the input impedance phase angle after the compensation network at the receiving end is adjusted. The transmitter control unit adjusts the high-frequency AC power supply according to the obtained input impedance phase angle and the corresponding charging method, and adjusts the output voltage of the high-frequency AC power supply to the output voltage U p Or adjust the output current to output current I p .

2. A wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 1, characterized in that: The charging methods include constant current charging, constant voltage charging and constant current constant voltage charging.

3. The wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 2, characterized in that: When the charging mode is constant current charging mode, the specific process of the corresponding wireless charging is as follows: when wireless charging starts, the high-frequency AC power supply gradually increases the output voltage, and the charging current at both ends of the receiving end load gradually increases. The receiving end control unit compares the charging current at both ends of the load with the charging current demand value in real time. When the charging current reaches the charging current demand value, the duty cycle of the two power switching tubes in the receiving end compensation network is calculated, and the two power switching tubes are controlled to be turned on and off according to the calculated duty cycle of the two power switching tubes in the receiving end compensation network to maintain the charging current not exceeding the charging current demand value until charging is completed.

4. The wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 3 is characterized in that: When the duty cycle of the two power switch tubes in the receiving end compensation network is calculated to control the opening and closing of the two power switch tubes, the input impedance phase angle is calculated in real time by the transmitting end control unit, and it is judged whether the input impedance meets the pure resistive condition. When the input impedance does not meet the pure resistive condition, the recorded output voltage U is used. p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output voltage of the high-frequency AC power supply to the output voltage U p .

5. The wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 2, characterized in that: When the charging mode is constant current and constant voltage charging, the battery management system of the load collects the load voltage in real time. When the load voltage is lower than the preset voltage, it is in the constant current charging stage. After the voltage reaches the preset voltage, the load switches from the constant current stage to the constant voltage stage and continues charging.

6. The wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 5, characterized in that: When the charging mode is constant current and constant voltage charging and is in its constant current charging stage, the specific process of the corresponding wireless charging is as follows: the receiving end control unit compares the charging current at both ends of the load with the charging current demand value in real time, and the receiving end control unit calculates the duty cycle of the two power switch tubes in the compensation network according to the comparison result, and controls the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network to maintain the charging current not exceeding the charging current demand value.

7. The wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 5, characterized in that: When the charging mode is constant current and constant voltage charging, and the charging is converted from the constant current stage to the constant voltage stage, the transmitter control unit calculates the input impedance phase angle in real time and determines whether the input impedance meets the pure resistive condition. When the input impedance does not meet the pure resistive condition, the output current I p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output current of the high-frequency AC power supply to the output current I p , the charging voltage at the receiving end reaches the required charging voltage value.

8. The wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 2, characterized in that: When the charging mode is constant voltage charging, the charging voltage demand value of the load remains unchanged, and the charging current demand value continues to decrease with the change of power. The corresponding specific process of wireless charging is as follows: when wireless charging starts, the high-frequency AC power supply gradually increases the output voltage, and the receiving end control unit compares the charging current and the charging current demand value in real time, and when the charging current increases to the charging current demand value, calculates the duty cycle of the two power switch tubes according to the comparison result, and controls the opening and closing of the two power switch tubes according to the duty cycle of the two power switch tubes to maintain the charging current not exceeding the current charging current demand value of the load. At the same time, the transmitting end control unit detects and calculates the transmitting end input impedance in real time. After detecting the change of the transmitting end input impedance, it calculates the output voltage U according to the recorded output voltage U. p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output voltage of the high-frequency AC power supply to the output voltage U p The receiving end control unit adjusts the two power switches in real time according to the comparison results to maintain the charging current to meet the current charging current demand value. At the same time, the transmitting end control unit calculates the input impedance phase angle in real time and determines whether the input impedance meets the pure resistive condition. When the input impedance does not meet the pure resistive condition, the output current I p Calculate the trigger pulse of the power switch tube in the high-frequency AC power supply, and control the opening and closing of the power switch tube in the high-frequency AC power supply according to the calculated trigger pulse, and adjust the output current of the high-frequency AC power supply to the output current I p , the charging voltage at the receiving end reaches the required charging voltage value.

9. A wireless charging phased constant current and constant voltage output control method adapted to offset working conditions according to claim 7 or 8, characterized in that: When the output current of the high-frequency AC power supply is adjusted to the output current I p The receiving end control unit also detects the charging voltage across the load in real time, compares the charging voltage with the charging voltage requirement value, and calculates the duty cycle of the two power switch tubes in the compensation network according to the comparison result, and controls the opening and closing of the two power switch tubes according to the calculated duty cycle of the two power switch tubes in the receiving end compensation network, maintaining the charging voltage at the charging voltage requirement value until charging is completed.

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