A multi-voltage compatible wireless power transfer system and a control method thereof

Abstract

The application provides a multi-voltage compatible wireless power transmission system and a control method thereof. The system comprises a transmitting end and a receiving end. The transmitting end is provided with a transmitting side compensation network, which comprises a first switch module and a plurality of transmitting coils. The first switch module selects to connect the transmitting coils in series to the compensation network, forming at least two different equivalent topologies of the transmitting end. The receiving end is provided with a receiving side reconfigurable compensation network, which comprises a second switch module and a passive compensation structure. The second switch module selectively connects one of the passive compensation structures to the network, so that the receiving end works in a constant current or constant voltage output mode. Through cooperation of the first switch module and the second switch module, the transmitting end and the receiving end can form a wireless power charging working mode. The application solves the problem of "special charging for special use" of the existing wireless charging system. A special charger is provided for each voltage, which leads to difficult maintenance and poor flexibility. The application realizes compatible charging of a single device for batteries of multiple voltage grades.

Description

Technical Field

[0001] This invention relates to the field of wireless power transmission technology, and more specifically, to a multi-voltage compatible wireless power transmission system and its control method. Background Technology

[0002] In magnetically coupled wireless power transfer systems, most designs are for specific battery models or fixed voltage levels, lacking versatility and compatibility. In actual industrial scenarios, charging equipment often uses different battery voltage levels due to differences in load capacity, operating speed, and functional modules.

[0003] However, the relevant technologies have at least one of the following problems: existing wireless charging systems are all "dedicated chargers for dedicated devices", that is, each voltage is paired with a charger, which makes different devices use batteries of different voltage levels, resulting in difficult maintenance and poor flexibility. Summary of the Invention

[0004] The technical problem solved by this invention is that existing wireless charging systems are all "dedicated chargers for dedicated devices", that is, each voltage is paired with a charger, which makes different devices use batteries of different voltage levels, resulting in difficult maintenance and poor flexibility.

[0005] To address the aforementioned problems, this invention provides a multi-voltage compatible wireless power transfer system, comprising: a transmitter and a receiver; a transmitter-side compensation network located at the transmitter; the transmitter-side compensation network includes a first switching module and multiple transmitting coils; the first switching module can selectively connect at least one of the multiple transmitting coils in series to the transmitter-side compensation network to form at least two different transmitter-side equivalent topologies; a receiver-side reconfigurable compensation network located at the receiver; the receiver-side reconfigurable compensation network includes a second switching module and at least two passive compensation structures; the second switching module can selectively connect one of the at least two passive compensation structures to the receiver-side reconfigurable compensation network to enable the receiver to operate in a constant current output mode or a constant voltage output mode; through the cooperation of the first switching module and the second switching module, the transmitter and receiver can form at least two wireless power charging operating modes.

[0006] Compared with existing technologies, the technical effects achieved by this solution are as follows: By selectively connecting multiple transmitting coils through the first switching module on the transmitting side, the system can form at least two different equivalent transmitting-side topologies, thereby adapting to battery loads of different voltage levels and switching output characteristics without changing the hardware structure; On the receiving side, the second switching module switches different passive compensation structures under the same set of rectifier circuits to achieve constant current / constant voltage output, avoiding the redundant design of two sets of rectifier units required in existing technologies; The cooperation between the first and second switching modules enables the transmitting and receiving ends to be synchronously reconfigured, forming multiple wireless power charging operating modes and achieving multiple charging capabilities, significantly improving the system's versatility and flexibility.

[0007] In one embodiment of the present invention, the transmitter-side compensation network further includes: a transmitter-side compensation capacitor; the transmitter coil includes: a first transmitter coil, a second transmitter coil, and a third transmitter coil; the first switching module includes a first switch and a second switch; the second transmitter coil is connected in series with the transmitter-side compensation capacitor to form a resonant branch, used to determine the fundamental resonant frequency of the transmitter-side compensation network; the first switch can selectively connect the first transmitter coil in series to the resonant branch or disconnect it from the resonant branch to change the equivalent series inductance of the transmitter-side compensation network; the second switch can selectively connect the third transmitter coil in series to the resonant branch or disconnect it from the resonant branch to change the equivalent series inductance of the transmitter-side compensation network; the connection state of the first transmitter coil and the third transmitter coil determines the equivalent topology of the transmitter side to correspond to different output voltage levels.

[0008] Compared with existing technologies, the technical effects achieved by this solution are as follows: the system can output four different voltage levels through four different combinations of the first switch, the second switch, and the transmitting coil; the resonant branch formed by the second transmitting coil and the transmitting-side compensation capacitor in series is always connected to the circuit, ensuring the stability of the fundamental resonant frequency, avoiding frequency drift caused by switch switching, and ensuring the transmission efficiency of the system; by selectively connecting or disconnecting the first and third transmitting coils, the equivalent series inductance is changed, thereby achieving smooth adjustment of the output voltage level and avoiding complex voltage regulation circuits.

[0009] In one embodiment of the present invention, the reconfigurable compensation network on the receiving side further includes: a receiving coil; the passive compensation structure includes: a first compensation capacitor; the receiving coil and the first compensation capacitor are connected in series to form a basic receiving branch.

[0010] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the receiving coil and the first compensation capacitor are connected in series to form the most basic series compensation topology, which ensures the basic resonance capability and power transmission efficiency of the receiving end.

[0011] In one embodiment of the present invention, the passive compensation structure further includes: a second compensation capacitor, a third compensation capacitor, and a compensation inductor; the second switching module includes a third switch and a fourth switch; one end of the second compensation capacitor is connected to the common terminal of the first compensation capacitor and the third compensation capacitor, and the other end of the second compensation capacitor is connected to the end of the receiving coil via the third switch; when the third switch is turned on, the second compensation capacitor is connected to the receiving base branch to change the compensation characteristics of the receiving side; one end of the compensation inductor is connected to the end of the receiving coil via the fourth switch, and the other end of the compensation inductor is connected to the end of the third compensation capacitor; when the fourth switch is turned on, the compensation inductor and the third compensation capacitor together constitute a CLC compensation network.

[0012] Compared with existing technologies, the technical effects achieved by this solution are as follows: By switching between the third and fourth switches, the same rectifier circuit can operate in two different compensation topologies sequentially; when the third switch is on, the second compensation capacitor is connected to form a series compensation network, resulting in constant current output; when the fourth switch is on, the compensation inductor is connected and forms a CLC compensation network with the third compensation capacitor, resulting in constant voltage output; only one rectifier circuit is needed to achieve CC-CV switching, which significantly reduces the number of diodes, capacitors, and other components compared to the existing technology that requires two rectifier units, thus reducing hardware costs and circuit board area.

[0013] In one embodiment of the present invention, the third switch and the fourth switch are not turned on at the same time; when the third switch is turned on and the fourth switch is turned off, the receiving end operates in constant current output mode; when the third switch is turned off and the fourth switch is turned on, the receiving end operates in constant voltage output mode.

[0014] Compared with existing technologies, the technical effects achieved by adopting this technical solution are as follows: limiting the third and fourth switches to not be turned on at the same time avoids short circuit faults or compensation network anomalies that may be caused by the simultaneous conduction of switches, thereby improving the safety and reliability of the system; at the same time, it provides the switch state combinations corresponding to the two working modes, making the design of the control system simple and clear.

[0015] In one embodiment of the present invention, both the third switch and the fourth switch are reverse series MOSFET structures; the reverse series MOSFET structure includes a first MOSFET and a second MOSFET; the source of the first MOSFET is connected to the source of the second MOSFET, or the drain of the first MOSFET is connected to the drain of the second MOSFET, forming a bidirectional conduction path; the third switch and the fourth switch are disposed in the AC circuit on the receiving side, and are used to achieve controllable bidirectional conduction and bidirectional blocking under AC excitation, so as to eliminate the unidirectional conduction effect caused by the inherent body diode of a single MOSFET.

[0016] Compared with existing technologies, the technical advantages achieved by this solution are as follows: Since the body diode of a single MOSFET has unidirectional conduction characteristics, it cannot achieve bidirectional blocking in an AC circuit. The reverse-series MOSFET structure connects the two body diodes in reverse series, thereby blocking current in both forward and reverse directions when the MOSFET is off.

[0017] In one embodiment of the present invention, the receiving end further includes a rectification and filtering module; the rectification and filtering module includes a full-bridge rectifier circuit and a filter capacitor; the full-bridge rectifier circuit is composed of four diodes, and the two AC input terminals of the full-bridge rectifier circuit are respectively connected to the AC output terminal of the reconfigurable compensation network on the receiving side; the filter capacitor is connected in parallel across the DC output terminal of the full-bridge rectifier circuit to filter the rectified DC power; the DC output terminal of the full-bridge rectifier circuit is used to connect to the battery load to output a stable DC charging voltage and DC charging current.

[0018] Compared with existing technologies, the technical effects achieved by this solution are as follows: the full-bridge rectifier circuit converts the high-frequency AC power output from the reconfigurable compensation network on the receiving side into pulsating DC power, and the filter capacitor further filters out ripple, resulting in a smooth and stable DC voltage and current output that meets battery charging requirements.

[0019] In one embodiment of the present invention, the first switch and the second switch cooperate to form multiple switch state combinations to form multiple operating modes; the switch state combinations include: the first switch disconnects the first transmitting coil from the resonant branch, the second switch disconnects the third transmitting coil from the resonant branch, and the transmitting-side equivalent topology only includes the second transmitting coil and the transmitting-side compensation capacitor connected in series to form a first operating mode and corresponding to a first output voltage level; the first switch connects the first transmitting coil in series to the resonant branch, the second switch disconnects the third transmitting coil from the resonant branch, and the transmitting-side equivalent topology includes the first transmitting coil, the second transmitting coil and the transmitting-side compensation capacitor connected in series to form a first operating mode and corresponding to a first output voltage level. The system forms a second operating mode and corresponds to a second output voltage level. A first switch disconnects the first transmitting coil from the resonant branch, and a second switch connects the third transmitting coil in series to the resonant branch. The equivalent topology on the transmitting side includes the second transmitting coil, the third transmitting coil, and the transmitting-side compensation capacitor connected in series to form a third operating mode and correspond to a third output voltage level. A first switch connects the first transmitting coil in series to the resonant branch, and a second switch connects the third transmitting coil in series to the resonant branch. The equivalent topology on the transmitting side includes the first transmitting coil, the second transmitting coil, the third transmitting coil, and the transmitting-side compensation capacitor connected in series to form a fourth operating mode and correspond to a fourth output voltage level.

[0020] Compared with existing technologies, the technical effects achieved by this technical solution are as follows: the specific states of the first and second switches, which transmitting coils are connected in series, the equivalent topology, and the corresponding output voltage levels are all clearly correlated under each mode, which makes it easier for the control system to quickly and accurately switch to the target mode based on the identification results.

[0021] In one embodiment of the present invention, a control method for a multi-voltage compatible wireless power transmission system is provided. This control method can be applied to any of the aforementioned multi-voltage compatible wireless power transmission systems. The control method includes: identifying the voltage level of the connected battery load and determining a target operating mode based on the voltage level; controlling a first switching module on the transmitting side to selectively connect at least one of a plurality of transmitting coils in series to a transmitting-side compensation network, forming a transmitting-side equivalent topology corresponding to the target operating mode; controlling a second switching module on the receiving side to connect the reconfigurable compensation network on the receiving side to a first passive compensation structure in the passive compensation structure, so that the receiving side operates in a constant current output mode to charge the battery load at a constant current; detecting the charging voltage of the battery load in real time, and when the charging voltage reaches a preset constant voltage switching threshold, controlling the second switching module to switch the reconfigurable compensation network on the receiving side to a second passive compensation structure in the passive compensation structure, so that the receiving side switches from a constant current output mode to a constant voltage output mode; and continuing to charge the battery load at a constant voltage until charging is complete.

[0022] Compared with existing technologies, the technical effects achieved by this solution are as follows: by detecting the charging voltage in real time and comparing it with a preset threshold, the system automatically switches from constant current mode to constant voltage mode when the threshold is reached, thus avoiding the risk of overcharging or undercharging. Furthermore, the constant current stage ensures fast charging without exceeding the battery's capacity, while the constant voltage stage ensures the battery is fully charged without overcharging. The combination of these two stages extends battery life and improves charging safety.

[0023] In one embodiment of the present invention, the charging voltage of the battery load is detected in real time. When the charging voltage reaches a preset constant voltage switching threshold, the second switching module is controlled to switch the reconfigurable compensation network of the receiving side to the second passive compensation structure, so that the receiving end switches from constant current output mode to constant voltage output mode. This includes: detecting the charging voltage of the battery load in real time to obtain an analog electrical signal; converting the analog electrical signal into a digital signal; processing the digital signal to extract and calculate the effective voltage value of the fundamental component of the digital signal; comparing the calculated effective voltage value with the preset constant voltage switching threshold; when the effective voltage value is greater than the preset constant voltage switching threshold, the receiving end outputs a PWM drive signal to control the second switching module to switch the reconfigurable compensation network of the receiving side from the first passive compensation structure to the second passive compensation structure.

[0024] Compared with existing technologies, the technical effects achieved by this solution are as follows: through real-time detection, analog-to-digital conversion, and extraction of the fundamental component RMS value, the true RMS value of the charging voltage is accurately obtained, avoiding false detection caused by harmonic interference; and the calculated RMS value is compared with a preset reference value, and a switching is triggered when the detected value is greater than the reference value, ensuring that the switching point is at the optimal time, neither too early leading to insufficient constant charging nor too late leading to overcharging risk.

[0025] By adopting the technical solution of the present invention, the following technical effects can be achieved: (1) By selectively connecting multiple transmitting coils through the first switching module on the transmitting side, the system can form at least two different equivalent topologies on the transmitting side, thereby adapting to battery loads of different voltage levels and switching output characteristics without changing the hardware structure; the receiving side switches different passive compensation structures under the same set of rectifier circuits through the second switching module to achieve constant current / constant voltage output, avoiding the redundant design of two sets of rectifier units required in the prior art; the cooperation between the first switching module and the second switching module enables the transmitting end and the receiving end to be reconfigured synchronously, forming multiple wireless power charging working modes, realizing multiple charging capabilities, and significantly improving the versatility and flexibility of the system; (2) By detecting the charging voltage in real time and comparing it with the preset threshold, the constant current mode is automatically switched to the constant voltage mode when the threshold is reached, thus avoiding the risk of overcharging or undercharging. In addition, the constant current stage ensures fast charging without exceeding the battery's capacity, and the constant voltage stage ensures that the battery is fully charged without overcharging. The combination of the two stages extends the battery life and improves charging safety. (3) The system can output four different voltage levels through four different combinations of the first switch, the second switch and the transmitting coil; the resonant branch formed by the second transmitting coil and the transmitting side compensation capacitor is always connected to the circuit, ensuring the stability of the fundamental resonant frequency, avoiding frequency drift caused by switch switching, and ensuring the transmission efficiency of the system; by selectively connecting or disconnecting the first and third transmitting coils, the equivalent series inductance is changed, thereby achieving smooth adjustment of the output voltage level and avoiding complex voltage regulation circuits. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 A schematic diagram of a multi-voltage compatible wireless power transmission system provided in an embodiment of the present invention; Figure 2 for Figure 1 The diagram shows the structure of the multi-voltage compatible wireless power transfer system in the first operating mode. Figure 3 for Figure 2 The equivalent circuit diagram of the multi-voltage compatible wireless power transfer system in constant current mode under the first operating mode is shown below. Figure 4 for Figure 2 The equivalent circuit diagram of the multi-voltage compatible wireless power transfer system shown in the constant voltage mode under the first operating mode is shown below. Figure 5 for Figure 1 The diagram shows the structure of the multi-voltage compatible wireless power transfer system in the second operating mode. Figure 6 for Figure 1 The diagram shows the structure of the multi-voltage compatible wireless power transfer system in the third operating mode. Figure 7 for Figure 1 The diagram shows the structure of the multi-voltage compatible wireless power transfer system in the fourth operating mode. Figure 8 for Figure 1 The overall mode switching control framework of the multi-voltage compatible wireless power transfer system shown in the figure; Figure 9 for Figure 1 The overall CC-CV switching control architecture of the multi-voltage compatible wireless power transfer system shown is illustrated. Figure 10 A flowchart illustrating a control method for a multi-voltage compatible wireless power transfer system provided in an embodiment of the present invention. Detailed Implementation

[0027] Embodiments of the present invention will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a link, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] See Figure 1 , Figure 1 This is a schematic diagram of a multi-voltage compatible wireless power transfer system provided in an embodiment of the present invention; combined with Figures 2 to 7 Specifically, a multi-voltage compatible wireless power transmission system includes: a transmitter and a receiver, a transmitter-side compensation network, and a receiver-side reconfigurable compensation network; the transmitter-side compensation network is located at the transmitter; the transmitter-side compensation network includes a first switching module and multiple transmitting coils; the first switching module can selectively connect at least one of the multiple transmitting coils in series to the transmitter-side compensation network to form at least two different transmitter-side equivalent topologies; the receiver-side reconfigurable compensation network is located at the receiver; the receiver-side reconfigurable compensation network includes a second switching module and at least two passive compensation structures; the second switching module can selectively connect one of the at least two passive compensation structures to the receiver-side reconfigurable compensation network to enable the receiver to operate in a constant current output mode or a constant voltage output mode; through the cooperation of the first switching module and the second switching module, the transmitter and receiver can form at least two wireless power charging operating modes.

[0031] Furthermore, the multi-voltage compatible wireless power transfer system of this application is a dual-sided reconfigurable WPT system architecture.

[0032] Specifically, the left half of the multi-voltage compatible wireless power transmission system is the transmitter, and the right half is the receiver. The transmitter is equipped with a transmitter-side compensation network, which includes a first switching module and multiple transmitting coils. The first switching module can selectively connect at least one of the multiple transmitting coils in series to the transmitter-side compensation network, thereby forming at least two different transmitter-side equivalent topologies. The receiver is equipped with a receiver-side reconfigurable compensation network, which includes a second switching module and at least two passive compensation structures. The second switching module can selectively connect one of the passive compensation structures to the receiver-side reconfigurable compensation network, enabling the receiver to operate in constant current output mode or constant voltage output mode. Through the cooperation of the first and second switching modules, the transmitter and receiver together form at least two wireless power charging operating modes.

[0033] For example, the first switch module has two connection points with the transmitting-side compensation network; the second switch module has two connection points with the receiving-side reconfigurable compensation network; when the first switch module is connected to any connection point of the transmitting-side compensation network and the second switch module is connected to any connection point of the receiving-side reconfigurable compensation network, there are four wireless power charging operating modes; by connecting the first switch module and the second switch module to different connection points, the transmitting end and the receiving end can form multiple wireless power charging operating modes.

[0034] Furthermore, the transmitter-side compensation network also includes: transmitter-side compensation capacitor C P ; The transmitting coil includes: a first transmitting coil L1 and a second transmitting coil L2. P and the third transmitting coil L2; The first switch module includes a first switch S1 and a second switch S2; Second transmitting coil L P With the transmitter-side compensation capacitor C P They are connected in series to form a resonant branch, which is used to determine the fundamental resonant frequency of the transmitter-side compensation network; The first switch S1 can selectively connect the first transmitting coil L1 in series to the resonant branch or disconnect it from the resonant branch to change the equivalent series inductance of the transmitting-side compensation network. The second switch S2 can selectively connect the third transmitting coil L2 in series to the resonant branch or disconnect it from the resonant branch to change the equivalent series inductance of the transmitting side compensation network. The connection status of the first transmitting coil L1 and the third transmitting coil L2 determines the equivalent topology on the transmitting side to correspond to different output voltage levels.

[0035] Furthermore, the transmitting-side compensation network includes a first capacitor C1 and a second capacitor C2; the first capacitor C1 is connected in series with the first transmitting coil L1, and the second capacitor C2 is connected in series with the third transmitting coil L2.

[0036] Specifically, the second transmitting coil L P With the transmitter-side compensation capacitor C P The coils are connected in series to form a resonant branch. The resonant branch is used to determine the fundamental resonant frequency of the transmitting-side compensation network to ensure that the transmission system achieves resonance at the operating frequency, thereby improving transmission efficiency. The first switch S1 can selectively connect the first transmitting coil L1 in series to the above-mentioned resonant branch, or disconnect it from the resonant branch. The second switch S2 can selectively connect the third transmitting coil L2 in series to the resonant branch, or disconnect it from the resonant branch. By connecting or disconnecting different transmitting coils, the equivalent series inductance of the transmitting-side compensation network can be changed, thereby changing the output voltage level.

[0037] Combination Figure 1 In one example, the transmitter-side compensation network has a first connection point, a second connection point, a third connection point, and a fourth connection point; wherein the first connection point, the second connection point, the third connection point, and the fourth connection point correspond to... Figure 1 The numbers 1, 2, 3, and 4 correspond to the first switch S1 and the second switch S2, respectively. The first switch S1 corresponds to the first connection point and the second connection point, and the second switch S2 corresponds to the third connection point and the fourth connection point. When the first switch S1 is connected to the first connection point, the first capacitor C1 and the first transmitting coil L1 are connected to the resonant branch, that is, the first capacitor C1 and the first transmitting coil L1 are connected to the transmitting side compensation capacitor C. P Second transmitting coil L P In series; when the first switch S1 and the second connection point are connected, the first transmitting coil L1 and the first capacitor C1 are disconnected from the resonant branch; similarly, when the second switch S2 is connected to the fourth connection point, the second capacitor C2 and the third transmitting coil L2 are connected to the resonant branch, that is, the second capacitor C2 and the third transmitting coil L2 are connected to the transmitting-side compensation capacitor C P Second transmitting coil L P In series; when the second switch S2 is connected to the third connection point, the second capacitor C2 and the third transmitting coil L2 are disconnected from the resonant branch; the equivalent topology of the transmitting end is determined by the connection state of the first transmitting coil L1 and the third transmitting coil L2, and corresponds to different output voltage levels.

[0038] Furthermore, the reconfigurable compensation network on the receiving side also includes: a receiving coil L S The passive compensation structure includes: a first compensation capacitor C S1 ; Receiving coil and first compensation capacitor C S1 They are connected in series to form the basic receiving branch.

[0039] Specifically, the receiving coil L S The first compensation capacitor C of the passive compensation structure S1 The series connection forms the basic receiving branch; this branch is the basis for topology reconstruction on the receiving side and ensures basic resonance compensation capability.

[0040] Furthermore, the passive compensation structure also includes: a second compensation capacitor C S2 The third compensation capacitor C3 and the compensation inductor L3; the second switching module includes the third switch S3 and the fourth switch S4; the second compensation capacitor C S2 One end is connected to the first compensation capacitor C S1 The common terminal of the second compensation capacitor C3 and the third compensation capacitor C S2 The other end is connected to the receiving coil L via the third switch S3. S At the end; when the third switch S3 is turned on, the second compensation capacitor C S2 The receiving base branch is connected to change the compensation characteristics on the receiving side; one end of the compensation inductor L3 is connected to the receiving coil L via the fourth switch S4. S At the end of the compensation inductor L3, the other end is connected to the end of the third compensation capacitor C3. When the fourth switch S4 is turned on, the compensation inductor L3 and the third compensation capacitor C3 together form a CLC compensation network.

[0041] Specifically, the receiving coil L S One end is connected to the first compensation capacitor C S1 One end is connected in series; the first compensation capacitor C S1 The other end is simultaneously connected to the second compensation capacitor C. S2 And the third compensation capacitor C3; the second compensation capacitor C S2 One end is connected to the receiving coil L S The other end is connected to the first compensation capacitor C via the third switch S3. S1 Connection; one end of the compensation inductor L3 is connected to the receiving coil L via the fourth switch S4. S The other end is connected to the other end of the third compensation capacitor C3.

[0042] Furthermore, during operation, when the third switch S3 is turned on, the second compensating inductor C... S2 Connect to the receiving base branch, and the first compensation capacitor C S1 Together with the third compensation capacitor C3, they form a series compensation network. At this time, the total compensation capacitance on the receiving side is equal to the first compensation capacitor C. S1 Second compensation capacitor C S2When connected in series with the third compensation capacitor C3, the equivalent capacitance value is small, and the transmission system exhibits constant current output characteristics. When the fourth switch S4 is turned on, the compensation inductor L3 is connected and connected in series with the third compensation capacitor C3 to form a CLC compensation network, and the system exhibits constant voltage output characteristics. By switching the third switch S3 and the fourth switch S4, the compensation characteristics on the receiving side can be changed, thereby switching between constant current and constant voltage modes.

[0043] Furthermore, the third switch S3 and the fourth switch S4 are not turned on at the same time; When the third switch S3 is turned on and the fourth switch S4 is turned off, the receiver operates in constant current output mode. When the third switch S3 is off and the fourth switch S4 is on, the receiver operates in constant voltage output mode.

[0044] Specifically, the third switch S3 and the fourth switch S4 cannot be turned on simultaneously; when the third switch S3 is turned on and the fourth switch S4 is turned off, the receiver operates in constant current output mode; when the third switch S3 is turned off and the fourth switch S4 is turned on, the receiver operates in constant voltage output mode, in which the output voltage is stable at the rated voltage of the battery and the current gradually decreases until the battery is fully charged.

[0045] Furthermore, both the third switch S3 and the fourth switch S4 are reverse-connected MOSFET structures; The reverse series MOSFET structure includes a first MOSFET and a second MOSFET; The source of the first MOSFET is connected to the source of the second MOSFET, or the drain of the first MOSFET is connected to the drain of the second MOSFET, forming a bidirectional conduction path; The third switch S3 and the fourth switch S4 are disposed in the AC circuit on the receiving side to achieve controllable bidirectional conduction and bidirectional blocking under AC excitation, so as to eliminate the unidirectional conduction effect caused by the inherent body diode of a single MOSFET.

[0046] Specifically, the third switch S3 and the fourth switch S4 are composed of two N-channel MOSFETs connected in reverse series; the source of the first MOSFET is connected to the source of the second MOSFET (or the drain is connected to the drain), and the two gates are driven by the same PWM signal through an isolation driver; during operation, when the PWM output is high, the two MOSFETs are turned on simultaneously, and the current can flow in any direction, realizing bidirectional conduction; for example, when the current flows in the forward direction, the current flows from the first MOSFET channel to the second MOSFET channel; similarly, when the current flows in the reverse direction, the current flows from the second MOSFET channel to the first MOSFET channel.

[0047] Furthermore, when the PWM is low, both MOSFETs are turned off simultaneously. Since the two body diodes are connected in reverse series, regardless of the voltage polarity, one diode is always in a reverse bias state, thus the switch can bidirectionally block the current. The third switch S3 and the fourth switch S4 are set in the AC circuit on the receiving side. With the above structure, the compensation network will not fail due to the body diodes being mis-turned on during reconstruction, ensuring the reliability of CC-CV switching.

[0048] Furthermore, the receiver also includes a rectification and filtering module; The rectifier and filter module includes a full-bridge rectifier circuit and filter capacitors; The full-bridge rectifier circuit consists of four diodes, and the two AC input terminals of the full-bridge rectifier circuit are respectively connected to the AC output terminal of the reconfigurable compensation network on the receiving side. The filter capacitor is connected in parallel across the DC output terminals of the full-bridge rectifier circuit to filter the rectified DC power. The DC output terminal of the full-bridge rectifier circuit is used to connect to the battery load to output a stable DC charging voltage and DC charging current.

[0049] Specifically, the full-bridge rectifier circuit uses diodes Q1-Q4 to convert the AC input voltage phasor U... S With AC input current phasor I O Converted to DC charging voltage U B and DC charging current I B And through the filter capacitor C O Battery equivalent load R B Power supply; that is, the two AC input terminals of the full-bridge rectifier circuit are respectively connected to the AC output terminals of the reconfigurable compensation network on the receiving side, that is, the two ends of the third compensation capacitor C3; the full-bridge rectifier circuit converts the high-frequency AC power output from the receiving side into pulsating DC power.

[0050] Filter capacitor C O Connected in parallel across the DC output terminals of the full-bridge rectifier circuit, it filters the rectified DC power to reduce ripple. The DC output terminals of the full-bridge rectifier circuit are used to connect the battery load R. B It outputs a stable DC charging voltage and DC charging current.

[0051] Furthermore, the first transmitting coil L1 and the second transmitting coil L P The third transmitting coil L2 and the receiving coil L S The four elements are mutually inductive to each other; that is, the first transmitting coil L1 and the second transmitting coil L... P Mutual inductance is M p1 The mutual inductance between the first transmitting coil L1 and the receiving coil is M. S1 Second transmitting coil L PThe mutual inductance between the third transmitting coil L2 and the third transmitting coil L2 is M. p2 Second transmitting coil L P and receiving coil L S Mutual inductance is M ps Receiver coil L S The mutual inductance between the third transmitting coil L2 and the third transmitting coil L2 is M. s2 .

[0052] further, Figure 1 I1, I P I2, I S These are the AC current phasors for the corresponding circuits; I in This represents the total input current.

[0053] Furthermore, combined with Figure 1 Based on the Fourier harmonic decomposition principle, the fundamental phasor U of the full-bridge inverter output voltage in RMS value and DC input voltage U D The fundamental phasor of the input voltage of the full-bridge rectifier, U S RMS value and DC output voltage U B .

[0054] Furthermore, the first switch S1 and the second switch S2 cooperate to form multiple switch state combinations, thereby forming multiple working modes; Switch state combinations include: The first switch S1 disconnects the first transmitting coil L1 from the resonant branch, and the second switch S2 disconnects the third transmitting coil L2 from the resonant branch. The equivalent topology on the transmitting side only includes the second transmitting coil L2. P With the transmitter-side compensation capacitor C P They are connected in series to form a first operating mode and correspond to a first output voltage level; The first switch S1 connects the first transmitting coil L1 in series to the resonant branch, and the second switch S2 disconnects the third transmitting coil L2 from the resonant branch. The equivalent topology on the transmitting side includes the first transmitting coil L1 and the second transmitting coil L2. P With the transmitter-side compensation capacitor C P They are connected in series to form a second operating mode and correspond to a second output voltage level; The first switch S1 disconnects the first transmitting coil L1 from the resonant branch, and the second switch S2 connects the third transmitting coil L2 in series to the resonant branch. The equivalent topology on the transmitting side includes the second transmitting coil L1. P The third transmitting coil L2 and the transmitting-side compensation capacitor C P They are connected in series to form a third operating mode and correspond to a third output voltage level; The first switch S1 connects the first transmitting coil L1 in series to the resonant branch, and the second switch S2 connects the third transmitting coil L2 in series to the resonant branch. The equivalent topology on the transmitting side includes the first transmitting coil L1 and the second transmitting coil L2. P The third transmitting coil L2 and the transmitting-side compensation capacitor C P They are connected in series to form a fourth operating mode and correspond to a fourth output voltage level.

[0055] Combination Figure 2 Specifically, Figure 2 The left side shows the equivalent circuit of the transmitter in the first operating mode, and the right side shows the receiver. In the first operating mode, the first switch S1 on the transmitter side switches to the second connection point, disconnecting the first transmitting coil L1 and the first capacitor C1 from the resonant branch; the second switch S2 on the transmitter side switches to the third connection point, disconnecting the second capacitor C2 and the third transmitting coil L2 from the resonant branch; in this mode, only the second transmitting coil L2 remains. P and the transmitting side compensation capacitor C P The resulting resonant branch operates and interacts with the receiving coil L. S This constitutes a coupling mechanism, with a corresponding mutual inductance of M. ps The circuit on the right side of the diagram is a reconfigurable circuit on the receiving side, used to realize topology switching and complete the smooth transition between CC mode and CV mode.

[0056] When the transmitter is in its first operating mode, the system first enters a constant current (CC) charging phase to meet the equipment's rapid power replenishment requirements. At this time, the third switch S3 used for topology switching on the receiver side is turned on, and the fourth switch S4 is turned off, along with the first compensation capacitor C. S1 The second compensation capacitor C in parallel S2 The circuit is connected, and together with the third compensation capacitor C3, it forms the total compensation capacitor on the receiving side in this mode, while the parallel compensation inductor L3 is removed.

[0057] Furthermore, combined with Figure 3 The equivalent circuit model for constant current operation corresponding to the first output mode; the area within the left box includes the emitter-side compensation capacitor C. P Second transmitting coil L P and its equivalent internal resistance R LP The area within the right-hand box contains the total compensation capacitor C on the receiving side. S Receiver coil L S and its equivalent internal resistance R LS .

[0058] When the voltage rises to the charging voltage threshold, to ensure the safety and stability of the system, the charging mode is switched from CC mode to CV mode. This is achieved by opening the third switch S3 and opening the fourth switch S4 to switch the receiving-side topology, thus realizing the mode switch. After the switch, the charging mode is connected to the first compensation capacitor C.S1 The second compensation capacitor C in parallel S2 The circuit is cut off, and the compensation inductor L3 is connected to the circuit, and together with the third compensation capacitor C3, they form the receiving-side CLC compensation topology in this mode.

[0059] Furthermore, combined with Figure 4 The structural framework and equivalent circuit model corresponding to the first output mode in constant voltage (CV) operating mode are as follows: Figure 5 As shown: The green shaded area includes the emitter-side compensation capacitor C. P Second transmitting coil L P and its equivalent internal resistance R LP The orange shaded area includes the first compensation capacitor C. S1 Receiver coil L S and its equivalent internal resistance R LS The blue shaded area includes the compensating inductor L3 and its equivalent internal resistance R. L1 The gray shaded area includes the third compensation capacitor C3.

[0060] Furthermore, combined with Figure 5 In the second operating mode, the equivalent circuit structure on the transmitting side is shown in the left box. At this time, the transmitting side's first switch S1 switches to the first connection point, connecting the first transmitting coil L1 and its branch to the resonant branch; the transmitting side's second switch S2 switches to the third connection point position, disconnecting the third transmitting coil L2 and its branch. The receiving end in the right box similarly switches between CC mode and CV mode by switching the third switch S3 and the fourth switch S4.

[0061] Furthermore, combined with Figure 6 In the third operating mode, the first switch S1 on the transmitting side switches to the second connection point, disconnecting the first transmitting coil L1 and its branch; the second switch S2 on the transmitting side switches to the fourth connection point, allowing the second transmitting coil L1 to... P It is put into operation synchronously with the third transmitting coil L2 and its branch. In this mode, the second transmitting coil L... P It is connected in series with the third transmitting coil L2 in the circuit, and with the receiving coil L S It constitutes a coupling transmission mechanism.

[0062] Furthermore, combined with Figure 7 In the fourth operating mode, the equivalent circuit on the transmitting side is shown in the left-hand box. At this time, the first switch S1 on the transmitting side switches to the first connection point, and the second switch S2 switches to the fourth connection point position, causing the first transmitting coil L1 and the second transmitting coil L2 to connect... P The third transmitting coil L2 and its corresponding branch are all connected to the circuit; in this mode, the first transmitting coil L1 and the second transmitting coil L2 are connected to the circuit. PIt is connected in series with the third transmitting coil L2 and with the receiving coil L S Forming a coupling transmission mechanism.

[0063] Furthermore, the first operating mode meets the charging requirements at a voltage level of 40V; the second operating mode meets the charging requirements at a voltage level of 48V; the third operating mode meets the charging requirements at a voltage level of 60V; and the fourth operating mode meets the charging requirements at a voltage level of 72V.

[0064] Furthermore, the power transmission system can communicate wirelessly via Bluetooth.

[0065] Furthermore, combined with Figures 8 to 10 The present invention also provides a control method for a multi-voltage compatible wireless power transmission system. This control method can be applied to any of the multi-voltage compatible wireless power transmission systems described above. The control method includes: S1: Identify the voltage level of the connected battery load and determine the target operating mode based on the voltage level; S2: Based on the target operating mode, control the operation of the first switching module on the transmitting side to selectively connect at least one of the multiple transmitting coils in series to the transmitting side compensation network, forming an equivalent transmitting topology corresponding to the target operating mode; S3: Control the second switch module of the receiving end to operate, so that the reconfigurable compensation network of the receiving side can be connected to the first passive compensation structure in the passive compensation structure, so that the receiving end can work in constant current output mode and charge the battery load with constant current. S4: Real-time detection of the charging voltage of the battery load. When the charging voltage reaches the preset constant voltage switching threshold, control the second switch module to switch the reconfigurable compensation network of the receiving side to the second passive compensation structure in the passive compensation structure, so that the receiving end switches from constant current output mode to constant voltage output mode. S5: Continue to charge the battery load at a constant voltage until charging is complete.

[0066] Among them, the preset constant voltage switching threshold U ref Set according to the battery type, for example, set 48V lithium battery to 44V.

[0067] Specifically, combined Figure 8 and Figure 9 After the system is powered on, it obtains the voltage level of the connected battery load through a handshake protocol and determines the corresponding target mode from four operating modes based on the voltage level. For example, if a 48V voltage is detected, the second operating mode is selected. According to the target mode, the controller controls the first switch S1 and the second switch S2 of the transmitter to operate. Then, the controller controls the third switch S3 and the fourth switch S4 of the receiver to operate. The second switch module is controlled to operate by detecting the charging voltage of the battery load in real time until the battery load is fully charged.

[0068] For example, if a 48V battery is detected, the second operating mode is selected; the controller controls the first switch S1 to switch to the first connection point, so that the first transmitting coil L1 and its branch are connected to the resonant branch; the transmitting side second switch S2 switches to the third connection point position, so that the second transmitting coil L1 is connected to the resonant branch. P The branch circuit and its location are disconnected; the controller controls the third switch S3 to turn on and the fourth switch S4 to turn off. At this time, the receiving end is connected to the first passive compensation structure, that is, the second compensation is connected to the series compensation network, and the system enters the constant current charging stage. The constant current value is controlled in a closed loop by fine-tuning the phase angle or frequency of the transmitter-side inverter; during the constant current charging process, the charging voltage of the battery load is detected in real time; when U B ≥U ref After 100ms, a switching operation is performed: the third switch S3 is turned off, and the fourth switch S4 is turned on. The receiving end switches to the second passive compensation structure (L3 access, CLC compensation network), and the system switches from constant current mode to constant voltage mode. In constant voltage mode, the output voltage stabilizes at the battery's full charge voltage, and the charging current gradually decreases. When the charging current drops to the set value and remains there for a period of time, charging is considered complete, and the system stops power output.

[0069] Furthermore, the charging voltage of the battery load is monitored in real time. When the charging voltage reaches a preset constant voltage switching threshold, the second switching module is controlled to switch the reconfigurable compensation network on the receiving side to the second passive compensation structure, thereby switching the receiving end from constant current output mode to constant voltage output mode. This includes: Real-time detection of the charging voltage of the battery load to obtain analog electrical signals; Convert analog electrical signals into digital signals; The digital signal is processed to extract and calculate the effective voltage value of the fundamental component of the digital signal; The calculated effective voltage value is compared with the preset constant voltage switching threshold. When the effective voltage value is greater than the preset constant voltage switching threshold, the receiving end outputs a PWM drive signal to control the second switching module to switch the reconfigurable compensation network on the receiving side from accessing the first passive compensation structure to accessing the second passive compensation structure.

[0070] Wherein, the battery voltage is UB i i = 1, 2, 3, 4, representing the corresponding operating modes; for example, the battery voltage is U. B1 This is the first working mode.

[0071] Specifically, a voltage sensor is installed on the receiving side, which is connected to the DC output terminal of the rectifier and filter module. During constant current charging, the voltage sensor monitors the charging voltage UB of the battery load in real time. i(Where i=1, 2, 3, 4 correspond to the four operating modes), and converts the detected voltage value into a continuous analog electrical signal; the analog electrical signal output by the voltage sensor is sent to an analog-to-digital converter (ADC). The ADC converts the analog signal into a digital signal; the digital signal is sent to the voltage RMS value calculation module. This module first extracts the fundamental component of the signal through a fast Fourier transform or a digital bandpass filter, filtering out higher harmonic noise. Then, it calculates the RMS value of the fundamental component to obtain the accurate fundamental voltage RMS value.

[0072] The calculated effective value of the fundamental voltage is sent to the comparison module. Simultaneously, the controller reads the preset constant voltage switching threshold UB. i _ref, the constant voltage switching threshold is pre-calibrated according to the battery type and charging curve, for example, it is set to 44V for a 48V lithium battery; the comparison module compares the two values ​​and outputs the comparison result.

[0073] The output of the comparison module is sent to the receiving-side controller; the controller then evaluates the comparison result. If the effective value of the fundamental voltage is greater than the preset constant voltage switching threshold UB i_ If ref, the controller generates two complementary PWM drive signals from the PWM output port. These two PWM signals are amplified by the isolation drive circuit and then control the actions of the third switch S3 and the fourth switch S4 respectively: the third switch S3 is turned off, and the fourth switch S4 is turned on. Thus, the reconfigurable compensation network on the receiving side switches from being connected to the first passive compensation structure (series compensation network, corresponding to constant current mode) to being connected to the second passive compensation structure (CLC compensation network, corresponding to constant voltage mode), completing the working mode switch.

[0074] If the effective value of the fundamental voltage is less than or equal to the preset constant voltage switching threshold, the controller maintains the current output state (i.e., the third switch S3 is on and the fourth switch S4 is off), does not perform the switching, and returns to continue detection until the switching conditions are met.

[0075] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A multi-voltage compatible wireless power transfer system, characterized in that, include: Transmitter and receiver; A transmitter-side compensation network is located at the transmitter end; the transmitter-side compensation network includes a first switching module and multiple transmitter coils; The first switching module can selectively connect at least one of the plurality of transmitting coils in series to the transmitting-side compensation network to form at least two different transmitting-side equivalent topologies; A receiver-side reconfigurable compensation network is provided at the receiving end; the receiver-side reconfigurable compensation network includes a second switching module and at least two passive compensation structures; The second switching module can selectively connect one of at least two passive compensation structures to the receiver-side reconfigurable compensation network to enable the receiver to operate in constant current output mode or constant voltage output mode. The first switch module and the second switch module work together to enable the transmitter and the receiver to form at least two wireless power charging operating modes.

2. The multi-voltage compatible wireless power transmission system according to claim 1, characterized in that, The transmitter-side compensation network also includes: a transmitter-side compensation capacitor; The transmitting coil includes: a first transmitting coil, a second transmitting coil, and a third transmitting coil; The first switch module includes a first switch and a second switch; The second transmitting coil is connected in series with the transmitting-side compensation capacitor to form a resonant branch, which is used to determine the fundamental resonant frequency of the transmitting-side compensation network; The first switch can selectively connect the first transmitting coil in series to the resonant branch or disconnect it from the resonant branch to change the equivalent series inductance of the transmitting-side compensation network. The second switch can selectively connect the third transmitting coil in series to the resonant branch or disconnect it from the resonant branch to change the equivalent series inductance of the transmitting-side compensation network; The connection status of the first transmitting coil and the third transmitting coil determines the equivalent topology of the transmitting side to correspond to different output voltage levels.

3. The multi-voltage compatible wireless power transfer system according to claim 1, characterized in that, The reconfigurable compensation network on the receiving side also includes: a receiving coil; The passive compensation structure includes: a first compensation capacitor; The receiving coil is connected in series with the first compensation capacitor to form the basic receiving branch.

4. The multi-voltage compatible wireless power transmission system according to claim 3, characterized in that, The passive compensation structure further includes: a second compensation capacitor, a third compensation capacitor, and a compensation inductor; The second switch module includes a third switch and a fourth switch; One end of the second compensation capacitor is connected to the common terminal of the first compensation capacitor and the third compensation capacitor, and the other end of the second compensation capacitor is connected to the end of the receiving coil via the third switch; when the third switch is turned on, the second compensation capacitor is connected to the receiving base branch to change the compensation characteristics of the receiving side. One end of the compensation inductor is connected to the end of the receiving coil via the fourth switch, and the other end of the compensation inductor is connected to the end of the third compensation capacitor. When the fourth switch is turned on, the compensation inductor and the third compensation capacitor together form a CLC compensation network.

5. The multi-voltage compatible wireless power transfer system according to claim 4, characterized in that, The third switch and the fourth switch are not turned on at the same time; When the third switch is turned on and the fourth switch is turned off, the receiving end operates in constant current output mode; When the third switch is off and the fourth switch is on, the receiving end operates in constant voltage output mode.

6. The multi-voltage compatible wireless power transfer system according to claim 4, characterized in that, Both the third switch and the fourth switch are reverse-connected MOSFET structures; The reverse series MOSFET structure includes a first MOSFET and a second MOSFET; The source of the first MOSFET is connected to the source of the second MOSFET, or the drain of the first MOSFET is connected to the drain of the second MOSFET, forming a bidirectional conduction path; The third and fourth switches are disposed in the AC circuit on the receiving side to achieve controllable bidirectional conduction and bidirectional blocking under AC excitation, so as to eliminate the unidirectional conduction effect caused by the inherent body diode of a single MOSFET.

7. The multi-voltage compatible wireless power transfer system according to claim 1, characterized in that, The receiving end also includes a rectification and filtering module; The rectifier and filter module includes a full-bridge rectifier circuit and a filter capacitor; The full-bridge rectifier circuit consists of four diodes, and the two AC input terminals of the full-bridge rectifier circuit are respectively connected to the AC output terminal of the reconfigurable compensation network on the receiving side. The filter capacitor is connected in parallel across the DC output terminals of the full-bridge rectifier circuit to filter the rectified DC power. The DC output terminal of the full-bridge rectifier circuit is used to connect to the battery load to output a stable DC charging voltage and DC charging current.

8. The multi-voltage compatible wireless power transmission system according to claim 2, characterized in that, The first switch and the second switch work together to form multiple switch state combinations, thereby forming multiple working modes; The switch state combinations include: The first switch disconnects the first transmitting coil from the resonant branch, and the second switch disconnects the third transmitting coil from the resonant branch. The equivalent topology on the transmitting side only includes the second transmitting coil connected in series with the transmitting side compensation capacitor to form a first operating mode and correspond to a first output voltage level. The first switch connects the first transmitting coil in series to the resonant branch, and the second switch disconnects the third transmitting coil from the resonant branch. The equivalent topology on the transmitting side includes the first transmitting coil, the second transmitting coil, and the transmitting side compensation capacitor connected in series to form a second operating mode and correspond to a second output voltage level. The first switch disconnects the first transmitting coil from the resonant branch, and the second switch connects the third transmitting coil in series to the resonant branch. The equivalent topology on the transmitting side includes the second transmitting coil, the third transmitting coil, and the transmitting side compensation capacitor connected in series to form a third operating mode and correspond to a third output voltage level. The first switch connects the first transmitting coil in series to the resonant branch, and the second switch connects the third transmitting coil in series to the resonant branch. The equivalent topology on the transmitting side includes the first transmitting coil, the second transmitting coil, the third transmitting coil, and the transmitting side compensation capacitor connected in series to form a fourth operating mode and correspond to a fourth output voltage level.

9. A control method for a multi-voltage compatible wireless power transfer system, characterized in that, The control method can be applied to the multi-voltage compatible wireless power transmission system as described in any one of claims 1 to 8, and the control method includes: Identify the voltage level of the connected battery load and determine the target operating mode based on the voltage level; According to the target operating mode, the first switching module on the transmitting side is controlled to operate, and at least one of the multiple transmitting coils is connected in series to the transmitting side compensation network to form an equivalent transmitting side topology corresponding to the target operating mode; The second switch module of the receiving end is controlled to operate, so that the reconfigurable compensation network of the receiving side is connected to the first passive compensation structure in the passive compensation structure, so that the receiving end works in constant current output mode and performs constant current charging on the battery load; The charging voltage of the battery load is detected in real time. When the charging voltage reaches the preset constant voltage switching threshold, the second switching module is controlled to switch the reconfigurable compensation network of the receiving side to the second passive compensation structure in the passive compensation structure, so that the receiving end switches from the constant current output mode to the constant voltage output mode. Continue to charge the battery load at a constant voltage until charging is complete.

10. The control method according to claim 9, characterized in that, The real-time detection of the battery load charging voltage, when the charging voltage reaches a preset constant voltage switching threshold, controls the second switching module to operate, causing the reconfigurable compensation network on the receiving side to switch to the second passive compensation structure, so that the receiving end switches from constant current output mode to constant voltage output mode, including: The charging voltage of the battery load is detected in real time to obtain an analog electrical signal; Convert analog electrical signals into digital signals; The digital signal is processed to extract and calculate the effective voltage value of the fundamental component of the digital signal; The calculated effective voltage value is compared with a preset constant voltage switching threshold. When the effective value of the voltage is greater than the preset constant voltage switching threshold, the receiving end outputs a PWM drive signal to control the second switching module to switch the reconfigurable compensation network on the receiving side from accessing the first passive compensation structure to accessing the second passive compensation structure.

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