Variable topology emergency shutdown system and method for wireless charging system

Abstract

The application relates to the technical field of wireless charging and discloses a variable topology emergency shutdown system and method for a wireless charging system, the variable topology emergency shutdown system for the wireless charging system comprising a transmitting end and a receiving end, the transmitting end comprising a transmitting coil, a primary side inverter, a primary side LCC / SS variable resonant cavity and a detection module, the receiving end comprising a receiving coil, a secondary side SS resonant cavity, a secondary side synchronous rectification bridge, a secondary side controller and a load, the primary side LCC / SS variable resonant cavity comprising a transmitting coil inductance Lp, a first capacitor Cp1, a second capacitor Cp2, a third capacitor Cps, a resonant inductance Lrp and a switching switch group, the secondary side SS resonant cavity comprising a receiving coil inductance Ls and a fourth capacitor Cs, after the system is switched from an SS-SS compensation network to an LCC-SS compensation network, the secondary side synchronous rectification bridge is used for short-circuiting the load, so that emergency shutdown can be realized under abnormal work.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and more particularly to a variable topology emergency shutdown system and method for wireless charging systems. Background Technology

[0002] In wireless charging systems, magnetic field coupling technology has become the mainstream method for wireless energy transmission due to its high efficiency and convenience. This process typically uses a coil as a medium to convert electromagnetic waves generated at the ground (transmitter) into alternating current (AC), which is then rectified into stable direct current (DC) to supply various vehicle-mounted loads. However, in specific fault conditions, such as when an emergency stop to energy output is required, simply relying on communication to notify the ground and suspend power transmission can lead to safety hazards or even serious accidents due to the time delay in signal transmission and response. Therefore, developing an emergency shutdown mechanism is particularly urgent.

[0003] In charging applications for humanoid robots and other small robots, the required charging system power is relatively low (around 500W, a low to medium power level), and the coil area requirement is even smaller (because robots do not want to install large receivers and circuits). In these low-power applications, a smaller coil area is required. Therefore, common wireless charging topologies with constant current / constant voltage characteristics (such as LCL and LCC topologies) are not suitable for this type of application. Typically, these wireless charging systems choose SS (series resonant topology) as their compensation topology. Compared to common wireless charging resonant cavity structures like LCL and LCC, SS can further reduce the coil size. Furthermore, SS has more flexible resonant properties, which makes its control method more complex than resonant cavity topologies like LCC that inherently possess constant voltage and constant current properties. SS topologies have many problems in practical applications, one of which is that their resonant characteristics are load-dependent. This can lead to severe overvoltage and overcurrent phenomena during sudden load changes or load shedding, which can severely damage the entire wireless charging system. To adapt to such application scenarios, researchers in this field have designed a variable topology emergency shutdown system and method for wireless charging systems. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and to provide an emergency shutdown system and method for a variable topology wireless charging system. When a fault occurs, the wireless charging system switches the SS-SS compensation network to the LCC-SS compensation network and short-circuits the load, thereby achieving emergency shutdown under abnormal operation.

[0005] The technical solution of this invention is: an emergency shutdown system and method for a variable topology structure in a wireless charging system. On one hand, the emergency shutdown system for a variable topology structure in a wireless charging system includes a transmitter and a receiver. The transmitter includes a transmitting coil, a primary-side inverter, a primary-side LCC / SS variable resonant cavity, and a detection module. The input terminal of the primary-side LCC / SS variable resonant cavity is connected to the input terminal of the primary-side inverter, and its output terminal is connected to the transmitting coil. The receiver includes a receiving coil, a secondary-side SS resonant cavity, a secondary-side synchronous rectifier bridge, a secondary-side controller, and a load. The input terminal of the secondary-side SS resonant cavity is connected to the receiving coil, and its output terminal is connected to the input terminal of the secondary-side synchronous rectifier bridge. The output terminal of the secondary-side synchronous rectifier bridge is connected to the load. The transmitting coil is coupled to the receiving coil. The primary-side LCC / SS variable resonant cavity includes a transmitting coil inductor Lp, a first capacitor Cp1, a second capacitor Cp2, a third capacitor Cps, a resonant inductor Lrp, and a switching switch group. The secondary-side SS... The resonant cavity includes a receiving coil inductor Ls and a fourth capacitor Cs. The primary-side LCC / SS variable resonant cavity and the secondary-side SS resonant cavity constitute an LCC / SS-SS topology compensation network. The detection module includes a peak hold circuit, a first overcurrent comparison circuit, a first buffer, and a primary-side controller. One end of the first overcurrent comparison circuit is electrically connected to the output of the peak hold circuit, and the other end is electrically connected to the primary-side controller through the first buffer. The input of the peak hold circuit is connected to the output of the primary-side inverter. The detection module is electrically connected to the switching switch group for triggering switching through detection. The primary-side controller is signal-connected to the secondary-side controller. The primary-side LCC / SS variable resonant cavity is used to switch the transmitter from the SS topology under normal operating conditions to the LCC topology under abnormal operating conditions through the switching switch group. After the system switches from the SS-SS compensation network to the LCC-SS compensation network, the secondary-side synchronous rectifier bridge is used to short-circuit the load, thereby achieving emergency shutdown under abnormal operating conditions.

[0006] As can be seen from the above scheme, the primary-side inverter is used to convert DC voltage into high-frequency AC power and to drive the resonant cavity. The primary-side control module and the secondary-side control module are used to control the receiving end and the transmitting end, respectively. The peak hold is used to track the peak value of the input signal, measure the value of the primary-side resonant current Ilrp or the series resonant current Ip, and output its resonant current peak value Ipp. The first overcurrent comparison circuit is used to compare the peak value of the peak hold with the protection threshold. When the set threshold is exceeded, an overcurrent protection signal is output. This invention achieves the switching of the variable resonant cavity from SS mode to LCC mode through the primary-side LCC / SS variable resonant cavity. Under normal operation, it is in SS mode, and it switches to LCC mode when an overcurrent occurs. When an emergency stop is initiated, the resonant cavity is short-circuited from the load through the secondary-side synchronous rectifier circuit to prevent the resonant current from surging due to sudden load changes, thereby protecting the entire wireless charging system. This invention achieves emergency stop in low-to-medium power wireless charging, which can promptly cut off the output power and protect the load and charging system. This invention fully utilizes the performance advantages of the SS topology in low-to-medium power, effectively reducing the coil area of ​​the receiver and the volume of the secondary-side converter.

[0007] The secondary-side synchronous rectifier bridge includes an upper rectifier and a lower rectifier. The upper rectifier includes a first arm and a third arm connected to the positive end of the load, and the lower rectifier includes a second arm and a fourth arm connected to the negative end of the load. Each of the first, third, second, and fourth arms is connected to at least one MOSFET and a corresponding synchronous rectifier controller. Therefore, the synchronous rectifier controller is electrically connected to each MOSFET and controls the operating state of the MOSFET in the corresponding arm.

[0008] The switching group includes a first switching switch and a second switching switch, and the first switching switch and the second switching switch operate synchronously.

[0009] One end of the first switching switch is connected to the primary-side inverter, and the other end is connected to the first capacitor Cp1 and the resonant inductor Lrp respectively. The other end of the resonant inductor Lrp is connected to one end of the second capacitor Cp2 and one end of the third capacitor Cps respectively. The other end of the first capacitor Cp1 and the other end of the third capacitor Cps are connected to one end of the transmitting coil through the second switching switch. The other end of the transmitting coil is connected to the other end of the second capacitor Cp2.

[0010] The receiving end also includes a second buffer and a second overcurrent comparison circuit. The input of the second overcurrent comparison circuit is connected to the secondary-side synchronous rectifier bridge, and the output is electrically connected to the secondary-side controller through the second buffer. Therefore, the buffer is used to eliminate interference or improve transfer characteristics, and the output overcurrent protection signal OCP is converted into overvoltage protection logic VP and overcurrent protection logic CP, respectively.

[0011] The wireless charging transmitter is further provided with a transmitter wireless communication module, and the wireless charging receiver is further provided with a receiver wireless communication module corresponding to the transmitter wireless communication module.

[0012] The transmitting end wireless communication module and the receiving end wireless communication module adopt one of WIFI, Bluetooth and near field communication.

[0013] On the other hand, this invention designs a wireless charging emergency shutdown method, applied to a variable topology emergency shutdown system for wireless charging systems. The method includes the following steps:

[0014] S1. The primary-side inverter converts the input DC power into AC power. The primary-side LCC / SS variable resonant cavity is an SS resonant cavity, which, together with the secondary-side SS resonant cavity, forms an SS-SS topology compensation network to achieve constant current charging.

[0015] S2. The peak hold measures the value of the primary side resonant current ILrp or the series resonant current Ip, and outputs its resonant current peak value Ipp.

[0016] S3. The first overcurrent comparison circuit on the primary side compares the peak resonant current Ipp with the set protection threshold. If the peak resonant current Ipp exceeds the set protection threshold, it proceeds to S4; otherwise, it remains in state S1.

[0017] S4. The first and second switching switches are switched synchronously, and the primary side LCC / SS variable resonant cavity switches from the SS structure mode to the LCC topology structure to achieve constant voltage charging. At this time, the system is an LCC-SS topology compensation network.

[0018] S5. The second overcurrent comparison circuit compares the output current Iout with the set protection threshold. If the output current Iout exceeds the set protection threshold, the receiving end short-circuits the load from the secondary side SS resonant cavity through the secondary side synchronous rectifier bridge.

[0019] S6. The output current Iout continues to decrease. When the output current Iout drops to zero, the output power of the wireless charging system stops, and the receiver sends a power stop message to the transmitter.

[0020] S7. After receiving the power stop information, the transmitter shuts down the primary inverter, and the primary side enters the shutdown state. After receiving the shutdown information of the primary inverter, the receiver controls the secondary side to enter the shutdown state, thereby realizing the emergency shutdown of the entire wireless charging system.

[0021] In S6, the transmitter sends a fault shutdown message through the transmitter wireless communication module and transmits the message to the receiver for interactive confirmation. Attached Figure Description

[0022] Figure 1 This is a system schematic diagram of the present invention;

[0023] Figure 2 This is a schematic diagram of the connection of the primary-side LCC / SS variable resonant cavity;

[0024] Figure 3 This is a schematic diagram of the SS-SS topology;

[0025] Figure 4 This is a schematic diagram of the LCC-SS topology;

[0026] Figure 5 This is a connection diagram of the secondary-side synchronous rectifier bridge circuit;

[0027] Figure 6 This is a connection diagram of the secondary-side synchronous rectifier controller circuit;

[0028] Figure 7 This is a flowchart of the present invention;

[0029] Figure 8 This is a waveform diagram of the switching shutdown process of this invention. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0031] like Figures 1 to 8As shown, this invention is a variable topology emergency stop system for a wireless charging system, including a transmitter and a receiver. The transmitter includes a transmitting coil, a primary-side inverter, a primary-side LCC / SS variable resonant cavity, and a detection module. The receiver includes a receiving coil, a secondary-side SS resonant cavity, a secondary-side synchronous rectifier bridge, a secondary-side controller, and a load. The receiver also includes a second buffer and a second overcurrent comparison circuit. The input of the second overcurrent comparison circuit is connected to the secondary-side synchronous rectifier bridge, and the output is electrically connected to the secondary-side controller through the second buffer. The primary-side LCC / SS variable resonant cavity includes a transmitting coil inductor Lp, a first capacitor Cp1, a second capacitor Cp2, a third capacitor Cps, a resonant inductor Lrp, and a switching group. The secondary-side SS resonant cavity includes a receiving coil inductor Ls and a fourth capacitor Cs. The coil inductance Ls are connected in series. The primary-side LCC / SS variable resonant cavity and the secondary-side SS resonant cavity constitute an LCC / SS-SS topology compensation network. The detection module includes a peak hold, a first overcurrent comparison circuit, a first buffer, and a primary-side controller. One end of the first overcurrent comparison circuit is electrically connected to the output of the peak hold, and the other end is electrically connected to the primary-side controller through the first buffer. The detection module is electrically connected to the switching switch group for switching triggered by detection. The primary-side LCC / SS variable resonant cavity is used to switch the transmitter from the SS topology under normal operating conditions to the LCC topology under abnormal operating conditions through the switching switch group. After the system switches from the SS-SS compensation network to the LCC-SS compensation network, the secondary-side synchronous rectifier bridge is used to short-circuit the load, thereby realizing emergency shutdown under abnormal operation.

[0032] In this embodiment, the controller of the primary-side converter of the present invention is used to implement functions such as power control, communication, and logic operation. It typically includes a high-performance DSP or other type of microprocessor, and a control board is constructed around this core. The DSP used in this invention is a TMS320F28035. The secondary-side controller uses an 8-bit microprocessor as its core, and is constructed using the SC8P series from AMEC (Advanced Micro-Fabrication Equipment Inc.). Both the first and second buffers are configured with logical OR operations. If any one of the overcurrent protection logic CPP / CPS or other fault logic OOP / OPS (used for extended functions) is valid, the protection signal PR-CTL / SR-CTL will be output as valid.

[0033] The switching group includes a first switching switch Sw1 and a second switching switch Sw2. The first switching switch Sw1 and the second switching switch Sw2 operate synchronously. One end of the first switching switch Sw1 is connected to the primary-side inverter, and the other end is connected to the first capacitor Cp1 and the resonant inductor Lrp, respectively. The other end of the resonant inductor Lrp is connected to one end of the second capacitor Cp2 and one end of the third capacitor Cps, respectively. The other end of the first capacitor Cp1 and the other end of the third capacitor Cps are connected to one end of the transmitting coil through the second switching switch. The other end of the transmitting coil is connected to the other end of the second capacitor Cp2. The transmitting coil is coupled to the receiving coil. In another embodiment, the switching group is a pair of solenoid valves to realize the switching of the primary-side LCC / SS variable resonant cavity. By controlling these two solenoid valves, the switching between LCC mode and SS mode can be realized. After switching, there will be symmetrical capacitors on both sides of the coil interface, thus realizing the SS structure.

[0034] The secondary-side synchronous rectifier bridge includes an upper rectifier bridge tube and a lower rectifier bridge tube. The upper rectifier bridge tube includes a first bridge arm and a third bridge arm connected to the positive end of the load. The lower rectifier bridge tube includes a second bridge arm and a fourth bridge arm connected to the negative end of the load. The first bridge arm, the third bridge arm, the second bridge arm, and the fourth bridge arm are respectively connected to at least one MOSFET and a synchronous rectifier controller corresponding to each MOSFET.

[0035] The secondary-side synchronous rectifier bridge of this invention has a total of four identical synchronous rectifier controllers, each of which controls all MOS drives in one bridge arm.

[0036] In this embodiment, as Figure 5 As shown, the secondary-side synchronous rectifier bridge includes four bridge arms, each containing a MOSFET. These four bridge arms are divided into two parts: the upper MOSFET and the lower MOSFET. The upper MOSFET is located at the positive load terminal of the secondary-side synchronous rectifier bridge and includes two bridge arms, Ss1 and Ss3. The upper MOSFET has two identical controller circuits (see...). Figure 6 The synchronous rectifier controllers for the upper MOSFETs in the rectifier bridge detect the source current signals (actually the same node CS) of each arm of the upper MOSFET and then output drive signals to the gates of the MOSFETs in the two arms of the upper MOSFET. This part is the same as the practical circuit of a general synchronous rectifier controller. Correspondingly, the lower MOSFET on the secondary side of the synchronous rectifier bridge includes two sets of arms, Ss2 and Ss4, respectively, at the negative load terminal. The lower MOSFET also has two identical controller circuits (see...). Figure 6The synchronous rectifier controller for the lower MOSFET in the rectifier bridge detects the source current signals of each arm of the lower MOSFET (at nodes MS1 and MS2), and then outputs the drive signal to the gate of the lower MOSFET. This part differs somewhat from the practical circuitry of a general synchronous rectifier controller.

[0037] When the short-circuit protection signal of the secondary converter is active, it will activate the forced drive active circuit, and then force the drive signal at the output of the synchronous rectifier controller to be high (or pull-up potential, so that the MOS of the bridge arm remains on).

[0038] The wireless charging transmitter is further equipped with a transmitter wireless communication module, and the wireless charging receiver is further equipped with a receiver wireless communication module corresponding to the transmitter wireless communication module. The transmitter wireless communication module and the receiver wireless communication module employ one of the following: Wi-Fi, Bluetooth, or near-field communication.

[0039] On the other hand, this invention discloses a wireless charging emergency shutdown method, applied to a variable topology emergency shutdown system for wireless charging systems. The method includes the following steps:

[0040] S1. The primary-side inverter converts the input DC power into AC power. The primary-side LCC / SS variable resonant cavity is an SS resonant cavity, which, together with the secondary-side SS resonant cavity, forms an SS-SS topology compensation network to achieve constant current charging.

[0041] S2. The peak hold measures the value of the primary side resonant current ILrp or the series resonant current Ip, and outputs its resonant current peak value Ipp.

[0042] S3. The first overcurrent comparison circuit compares the peak value of the resonant current Ipp with the set protection threshold. If the peak value of the resonant current Ipp exceeds the set protection threshold, it proceeds to S4; otherwise, it maintains the S1 state.

[0043] S4. The first and second switching switches are switched synchronously, and the primary side LCC / SS variable resonant cavity switches from the SS structure mode to the LCC topology structure to achieve constant voltage charging. At this time, the system is an LCC-SS topology compensation network.

[0044] S5. The second overcurrent comparison circuit compares the output current Iout with the set protection threshold. If the output current Iout exceeds the set protection threshold, the receiving end short-circuits the load from the secondary side SS resonant cavity through the secondary side synchronous rectifier bridge.

[0045] S6. The output current Iout continues to decrease. When the output current Iout drops to zero, the output power of the wireless charging system stops, and the receiver sends a power stop message to the transmitter.

[0046] S7. After receiving the power stop information, the transmitter shuts down the primary inverter, and the primary side enters the shutdown state. After receiving the shutdown information of the primary inverter, the receiver controls the secondary side to enter the shutdown state, thereby realizing the emergency shutdown of the entire wireless charging system.

[0047] In S6, the transmitter sends a fault shutdown message through the transmitter wireless communication module and transmits the message to the receiver for interactive confirmation.

[0048] In this embodiment, the modification of the general synchronous rectification circuit is achieved by adding two MOSFETs to the two controllers of the lower transistor, which can be implemented. Figure 6 The forced pull-up circuit shown is used in normal operation. During normal operation, these four sets of synchronous rectified currents can detect the zero-crossing point of the source current of the MOSFETs in each rectifier bridge and independently control the switching action of the MOSFETs in each rectifier bridge, thereby achieving synchronous rectification.

[0049] When the output protection signal SR-CTL is received as valid, the machine enters a shutdown operation. The MOSFETs added to the two sets of synchronous rectifier controllers of the lower transistor will force the output to a high level, which will turn on the two lower transistors of the rectifier bridge, thereby short-circuiting the resonant cavity from the load.

[0050] Figure 5 The resonant current Is and output current Iout on the secondary side are shown. It can be seen that after the emergency stop is initiated, the LCC / SS variable resonant cavity of the primary-side converter switches to LCC mode. At this time, the entire resonant cavity of the system is in LCC-SS mode. Due to the constant current and constant voltage characteristics of LCC-SS, from... Figure 5 As can be seen, the resonant current Is on the secondary side remains constant. However, because the two lower transistors of the secondary side synchronous rectifier bridge are conducting, short-circuiting the load from the secondary side SS resonant cavity, the output current Iout continuously decreases.

[0051] In this embodiment, when the first switching switch Sw1 and the second switching switch Sw2 are turned upwards, the primary-side LCC / SS variable resonant cavity becomes an SS resonant cavity, which, together with the secondary-side SS resonant cavity, forms an SS-SS topology compensation network to achieve constant current charging. After detecting an overcurrent, the primary-side converter simultaneously turns the first switching switch Sw1 and the second switching switch Sw2 downwards, switching the primary-side LCC / SS variable resonant cavity from SS mode to LCC mode. Simultaneously, the wireless communication module at the transmitting end sends a fault shutdown message and interacts with the receiving end to confirm the connection.

[0052] Furthermore, upon detecting an overcurrent on the secondary side, the secondary-side converter will activate the forced drive circuit, forcibly pulling up the synchronous rectified output of the lower MOSFET of the rectifier bridge to the required pull-up potential. The lower arm of the rectifier bridge will then be forcibly short-circuited. Simultaneously, the receiving end's wireless communication module will send a fault shutdown message and interact with the transmitting end for confirmation. These two processes are performed almost simultaneously and spontaneously by both converters, independent of communication speed and insensitive to their order. This is because whichever side enters the shutdown process first will inevitably cause the current on the other side to enter an abnormal state, triggering the output logic circuit to output a valid control value.

[0053] When the primary-side LCC / SS variable resonant cavity switches from SS mode to a forced short circuit between the LCC and the lower arm of the secondary-side rectifier bridge, the system output power will decrease until it reaches zero (the output current Iout will drop to zero, and the output voltage Vout depends on the nature of the load; for resistive loads, it will be proportional to the output current, while loads like batteries will cause the output voltage to rise for a few milliseconds before dropping to zero). However, the variable topology structure of this invention can achieve emergency shutdown, avoiding a surge in resonant current due to sudden load changes, thereby protecting the entire wireless charging system.

[0054] This invention enables emergency shutdown in low-to-medium power wireless charging, promptly cutting off output power and protecting the load and charging system from damage. It utilizes common circuitry and a lower-performance controller, avoiding complex control strategies and additional hardware costs. Furthermore, it fully leverages the performance advantages of the SS topology in low-to-medium power charging, effectively reducing the coil area at the receiver and the size of the secondary-side converter.

[0055] Finally, it should be emphasized that the above description is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable topology emergency shutdown system for a wireless charging system, comprising a transmitting end and a receiving end, characterized in that, The transmitting end comprises a transmitting coil, a primary-side inverter, a primary-side LCC / SS variable resonant cavity, and a detection module, an input end of the primary-side LCC / SS variable resonant cavity is connected with an input end of the primary-side inverter, and an output end is connected with the transmitting coil, the receiving end comprises a receiving coil, a secondary-side SS resonant cavity, a secondary-side synchronous rectification bridge, a secondary-side controller, and a load, an input end of the secondary-side SS resonant cavity is connected with the receiving coil, and an output end is connected with an input end of the secondary-side synchronous rectification bridge, an output end of the secondary-side synchronous rectification bridge is connected with the load, the transmitting coil is coupled with the receiving coil, the primary-side LCC / SS variable resonant cavity comprises a transmitting coil inductance Lp, a first capacitor Cp1, a second capacitor Cp2, a third capacitor Cps, a resonant inductance Lrp, and a switching switch group, the secondary-side SS resonant cavity comprises a receiving coil inductance Ls and a fourth capacitor Cs connected in series with the receiving coil inductance Ls, the primary-side LCC / SS variable resonant cavity and the secondary-side SS resonant cavity constitute an LCC / SS-SS topology compensation network, the detection module comprises a peak holder, a first overcurrent comparison circuit, a first buffer, and a primary-side controller, one end of the first overcurrent comparison circuit is electrically connected with an output end of the peak holder, the other end is electrically connected with the primary-side controller through the first buffer, an input end of the peak holder is connected with an output end of the primary-side inverter, the detection module is electrically connected with the switching switch group for triggering switching through detection, the primary-side controller is signal connected with the secondary-side controller, the primary-side LCC / SS variable resonant cavity is used for switching the transmitting end from the SS topology in normal working condition to the LCC topology in abnormal working condition through the switching switch group, after the system is switched from the SS-SS compensation network to the LCC-SS compensation network, the secondary-side synchronous rectification bridge is used for short-circuit load, so as to realize emergency shutdown under abnormal working condition; The switching switch group comprises a first switching switch and a second switching switch, the first switching switch and the second switching switch are synchronously operated, one end of the first switching switch is connected with the primary-side inverter, and the other end is connected with the first capacitor Cp1 and the resonant inductance Lrp respectively, the other end of the resonant inductance Lrp is connected with one end of the second capacitor Cp2 and one end of the third capacitor Cps respectively, the other end of the first capacitor Cp1 and the other end of the third capacitor Cps are connected with one end of the transmitting coil through the second switching switch, and the other end of the transmitting coil is connected with the other end of the second capacitor Cp2.

2. The variable topology emergency shutdown system for a wireless charging system of claim 1, wherein, The secondary side synchronous rectification bridge comprises an upper rectification bridge tube and a lower rectification bridge tube, the upper rectification bridge tube comprises a first bridge arm and a third bridge arm connected to the positive end of the load, and the lower rectification bridge tube comprises a second bridge arm and a fourth bridge arm connected to the negative end of the load, and the first bridge arm, the third bridge arm, the second bridge arm and the fourth bridge arm are respectively connected with at least one MOS tube and a synchronous rectification controller corresponding to the MOS tube.

3. The variable topology emergency shutdown system for a wireless charging system of claim 1, wherein, The receiving end further comprises a second buffer and a second overcurrent comparison circuit, the input end of the second overcurrent comparison circuit is connected with the secondary side synchronous rectification bridge, and the output end is electrically connected with the secondary side controller through the second buffer.

4. The variable topology emergency shutdown system for a wireless charging system of claim 1, wherein, The transmitting end is further provided with a transmitting end wireless communication module, and the receiving end is further provided with a receiving end wireless communication module corresponding to the transmitting end wireless communication module.

5. The variable topology emergency shutdown system for a wireless charging system of claim 4, wherein, The transmitting end wireless communication module and the receiving end wireless communication module adopt one of WIFI, Bluetooth and near field communication.

6. A wireless charging emergency shutdown method applied to the variable topology structure emergency shutdown system for the wireless charging system in any one of claims 1-5, the method comprising the following steps: S1, the primary side inverter converts the input direct current into alternating current, the primary side LCC / SS variable resonant cavity is an SS resonant cavity, which forms an SS-SS topology compensation network with the secondary side SS resonant cavity, and constant current charging is realized; S2, the peak value keeper measures the value of the resonant current ILrp or the series resonant current Ip and outputs the resonant current peak value Ipp; S3, the first overcurrent comparison circuit of the primary side compares the size of the resonant current peak value Ipp and the set protection threshold value, if the resonant current peak value Ipp exceeds the set protection threshold value, S4 is entered, otherwise S1 is maintained; S4, the first switching switch and the second switching switch are synchronously switched, the primary side LCC / SS variable resonant cavity is switched from the SS structure mode to the LCC topology structure, constant voltage charging is realized, and at this time the system is an LCC-SS topology compensation network; S5, the second overcurrent comparison circuit compares the size of the output current Iout and the set protection threshold value, if the output current Iout exceeds the set protection threshold value, the receiving end short-circuits the load from the secondary side SS resonant cavity through the secondary side synchronous rectification bridge; S6, the output current Iout continuously decreases, and when the output current Iout decreases to zero, the output power of the wireless charging system stops, and the receiving end sends power stop information to the transmitting end; S7, after the transmitting end receives the power stop information, the primary side inverter is shut down, the primary side part enters the shutdown state, and after the receiving end receives the shutdown information of the primary side inverter, the secondary side part enters the shutdown state, so as to realize the emergency shutdown of the whole wireless charging system.

7. The wireless charging emergency shutdown method of claim 6, wherein, In S6, the transmitting end sends fault shutdown information through the transmitting end wireless communication module, and the information is transmitted to the receiving end for interactive determination.

Images