Synchronous zero-voltage modulation system method of cascade system, medium and equipment

Abstract

The invention provides a synchronous zero voltage modulation system and method of a cascade system, a medium and equipment wherein the synchronous zero voltage modulation system of the cascade system comprises a power circuit module and a modulation system; the power circuit module comprises a front-stage four-switch buck-boost converter and a rear-stage LCC-LCC compensated bidirectional wireless charging system; the modulation system comprises a voltage compensation module, a current compensation module, a current comparison module, a synchronization module and a switch driving signal generation module, the output end of the voltage compensation module is connected with the input end of the synchronization module, and the output end of the current compensation module is connected with the input end of the synchronization module. The output end of the current comparison module is connected with the input end of the synchronization module, and the output end of the synchronization module is connected with the driving signal generation module. According to the invention, a plurality of time scales are adopted, the implementation condition of synchronous zero-voltage switch modulation is accurately calculated, the calculation speed is high, the memory occupation amount is small, and the zero-voltage switch synchronous modulation of the cascade system is realized.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics, and in particular to a synchronous zero voltage modulation system, method, medium and device of a cascade system. Background Art

[0002] Wireless charging systems have been widely used in electric vehicles, underwater unmanned vehicles, biomedicine, drones, consumer electronics and other fields. However, due to the limited battery capacity, the operating range, mileage, and operating time of the above-mentioned equipment are greatly restricted. Distributed DC power sources, such as photovoltaic power generation, energy storage power stations and other new energy sources, play an important role in reducing carbon emissions. In addition, distributed power sources can ensure the continuity of power supply in isolated power grid systems.

[0003] Distributed power sources such as photovoltaic power generation and energy storage batteries have the remarkable characteristics of wide distribution and wide voltage level range. The difference is that the rated charging power of the wireless charging system is designed based on the rated voltage. In order to solve the problems of the operating radius and cruising range of wireless charging equipment, using distributed power sources to power wireless charging equipment is a more effective solution.

[0004] The four-switch converter has the advantages of voltage increment and decrement capability and the ability to reduce switch voltage stress. It has been widely used as a DC power interface converter to realize distributed power supply to multi-input voltage level systems. Therefore, the cascade system is naturally formed. The wireless charging system needs to work at the resonant frequency, and the working power is usually tens to hundreds of kilohertz. In order to reduce switching losses, the operating frequency of the DC power converter is lower than the resonant frequency, usually several thousand hertz to tens of kilohertz. Taking the cascade system as a whole system, then, in this system, due to different operating frequencies, there will be variables working on multiple time scales.

[0005] Existing zero voltage switching (ZVS) modulation methods are all implemented for single-stage converters, requiring two microcontroller units (MCUs) to execute the modulation methods, increasing equipment costs. In addition, synchronization issues are not considered for the different operating frequencies of the two-stage structure. Existing modulation methods cannot be simply applied to cascade systems operating at multiple time scales and need to be redesigned. Summary of the invention

[0006] In view of the defects in the prior art, the purpose of the present disclosure is to provide a synchronous zero voltage modulation system, method, medium and device for a cascade system.

[0007] According to one aspect of the present disclosure, a synchronous zero voltage modulation system of a cascade system is provided, comprising:

[0008] Power circuit modules and modulation systems;

[0009] The power circuit module includes a front-stage topology structure and a rear-stage topology structure, the front-stage topology structure includes a four-switch buck-boost converter, the rear-stage topology structure includes a bidirectional wireless charging system with LCC-LCC compensation, the four-switch buck-boost converter is connected to the LCC-LCC compensation bidirectional wireless charging system, the four-switch buck-boost converter is used to convert the input voltage level, and the rear-stage wireless charging system is used for charging;

[0010] The modulation system includes a voltage compensation module, a current compensation module, a current comparison module, a synchronization module, and a switch drive signal generation module. The output end of the voltage compensation module is connected to the input end of the synchronization module, the output end of the current compensation module is connected to the input end of the synchronization module, the output end of the current comparison module is connected to the input end of the synchronization module, and the output end of the synchronization module is connected to the drive signal generation module. The modulation system is used to determine the pulse signals of the power switches of the preceding topology and the succeeding topology.

[0011] Optionally, the voltage compensation module includes a voltage regulator, the voltage regulator includes a multiplier and a proportional-integral regulator, the voltage regulator is connected to the synchronization module, and the voltage regulator is used to determine the voltage gain of the four-switch buck-boost converter;

[0012] The current compensation module includes a current regulator, the current regulator includes a multiplier and a proportional integral regulator, the current regulator is connected to the synchronization module, and the current regulator is used to determine whether the four-switch buck-boost converter operates under soft switching conditions;

[0013] The current comparison module includes a first operational amplifier, which is connected to the synchronization module and is used for the turn-on moment of the third field effect transistor of the four-switch buck-boost converter.

[0014] Optionally, the four-switch buck-boost transformer includes a first field effect transistor, a second field effect transistor, a third field effect transistor, a fourth field effect transistor, a first DC power supply, a first power inductor and a first output capacitor;

[0015] The drain of the first field effect transistor is connected to the positive electrode of the first DC power supply, and the source of the first field effect transistor is connected to the first end of the first power inductor;

[0016] The source of the second field effect transistor is connected to the second end of the first power inductor, and the drain of the second field effect transistor is connected to the positive electrode of the first output capacitor;

[0017] The drain of the third field effect transistor is connected to the source of the first field effect transistor, and the source of the third field effect transistor is connected to the negative electrode of the first DC power supply;

[0018] The drain of the fourth field effect transistor is connected to the source of the second field effect transistor, and the source of the fourth field effect transistor is connected to the negative electrode of the first output capacitor.

[0019] Optionally, when the first field effect transistor and the fourth field effect transistor are turned on, a first working state is represented, and the first working state is used to energize the first power inductor;

[0020] When the first field effect transistor and the second field effect transistor are turned on, a second working state is represented, and the second working state is used to simultaneously use the first DC power supply and the first power inductor to power the LCC-LCC compensated bidirectional wireless charging system;

[0021] When the second field effect transistor and the third field effect transistor are turned on, a third working state is represented, and the third working state is used to use the first power inductor to power the LCC-LCC compensated bidirectional wireless charging system;

[0022] When the third field effect transistor and the fourth field effect transistor are turned on, a fourth working state is represented, and the fourth working state is used to keep the current of the first power inductor constant.

[0023] Optionally, the LCC-LCC compensated bidirectional wireless charging system includes a primary inverter, a primary LCC compensation network, a primary coil, a secondary coil, a secondary LCC compensation network, a secondary active rectifier bridge, a second output capacitor and a second DC power supply;

[0024] The DC input end of the primary inverter is connected to the positive electrode of the first output capacitor and the negative electrode of the first output capacitor respectively, and the AC output end of the primary inverter is connected to the input end of the primary LCC compensation network;

[0025] The output end of the primary LCC compensation network is connected to two ends of the primary coil;

[0026] The input end of the secondary side LCC compensation network is connected to the two ends of the secondary side coil, and the output end of the secondary side LCC compensation network is connected to the AC input end of the secondary side active rectifier bridge;

[0027] The DC output end of the secondary active rectifier bridge is respectively connected to the positive electrode of the second output capacitor and the negative electrode of the second output capacitor;

[0028] The positive electrode of the second DC power supply is connected to the positive electrode of the second output capacitor, and the negative electrode of the second DC power supply is connected to the negative electrode of the second output capacitor.

[0029] According to a second aspect of the present disclosure, a synchronous zero voltage modulation method of a cascade system is provided, comprising:

[0030] The output voltage of the four-switch buck-boost converter of the previous topology structure and the preset voltage threshold are input into the voltage compensation module of the modulation system to determine the first input parameter;

[0031] Using the output voltage of the four-switch buck-boost converter as a second input parameter;

[0032] Inputting the output current of the primary inverter of the LCC-LCC compensated bidirectional wireless charging system and a preset first current threshold into the current compensation module of the modulation system to determine a third input parameter;

[0033] Determine an inner phase shift angle according to a full modal cycle of the bidirectional wireless charging system of the four-switch buck-boost converter and the LCC-LCC compensation, wherein the inner phase shift angle is used as a fourth input parameter;

[0034] Inputting the first power inductor current value and the preset second current threshold into the current comparison module to determine a fifth input parameter;

[0035] Using the output voltage of the first DC power supply as a sixth input parameter;

[0036] The external phase shift angles of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system are used as the seventh input parameter;

[0037] The operating frequency of the previous topology structure is used as an eighth input parameter, and the operating frequency of the subsequent topology structure is used as a ninth input parameter;

[0038] Input the first input parameter, the second input parameter, the third input parameter, the fourth input parameter, the fifth input parameter, the sixth input parameter, the seventh input parameter, the eighth input parameter, and the ninth input parameter into the synchronization module to determine the first working state time value, the second working state time value, the third working state time value, and the actual external shift phase angle of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system;

[0039] The first working state time value, the second working state time value, the third working state time value, and the actual external shift phase angles of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system are input into a driving signal generation module to determine the pulse signals of the power switches of the four-switch buck-boost converter and the LCC-LCC compensated bidirectional wireless charging system.

[0040] Optionally, the inputting the first input parameter, the second input parameter, the third input parameter, the fourth input parameter, the fifth input parameter, the sixth input parameter, the seventh input parameter, the eighth input parameter, and the ninth input parameter into the synchronization module to determine the first working state time value, the second working state time value, the third working state time value, and the actual external shift phase angle of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system includes:

[0041] Initialize the second input parameter, the sixth input parameter, the fourth input parameter, the seventh input parameter, the minimum sampling current value of the first power inductor, and the inverter current value of the LCC-LCC compensated bidirectional wireless charging system;

[0042] Defining a new time scale and a full modal period according to the eighth input parameter and the ninth input parameter;

[0043] When the first power inductor reaches a synchronous zero voltage state, using the first input parameter output by the voltage compensation module as the second working state time value;

[0044] When the four-switch buck-boost converter is in a buck working mode, determining the first working state time value according to a preset first expression and the new time scale;

[0045] Determine the third working state time value according to the volt-second balance principle and the second working state time value;

[0046] When the first power inductor does not reach the synchronous zero voltage state, if the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is less than a preset third current threshold, determining that the seventh input parameter is an actual external shift phase angle of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system;

[0047] When the first power inductor has not reached the synchronous zero voltage state, if the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is not less than the preset third current threshold, a new inner phase shift angle is iteratively determined according to a preset step size until the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is less than the preset third current threshold, and the new outer phase shift angle is determined as the actual outer phase shift angle of the primary and secondary sides of the LCC-LCC compensated bidirectional wireless charging system.

[0048] Optionally, the method further comprises:

[0049] A fourth working state time value is determined according to the working cycle of the four-switch buck-boost converter, the first working state time value, the second working state time value and the third working state time value.

[0050] According to a third aspect of the present disclosure, a non-temporary computer-readable storage medium is provided, on which a computer program is stored, characterized in that when the program is executed by a processor, the steps of any one of the methods provided in the second aspect of the present disclosure are implemented.

[0051] According to a fourth aspect of the present disclosure, there is provided an electronic device, characterized in that it includes:

[0052] a memory having a computer program stored thereon;

[0053] A processor is used to execute the computer program in the memory to implement the steps of any one of the methods provided in the second aspect of the present disclosure.

[0054] Compared with the prior art, the embodiments of the present disclosure have at least one of the following beneficial effects:

[0055] Through the above technical solution, a four-switch buck-boost converter is used for the power circuit, and multiple time scales are introduced to provide a modulation method with multiple time scales, thereby effectively increasing the execution speed of the modulation code.

[0056] The embodiments of the present disclosure reduce the execution time of full-mode periodic modulation by quickly retrieving the parameter n.

[0057] The embodiments of the present disclosure implement the execution of the modulation strategy and reduce the size of the storage space by establishing a two-dimensional lookup table of input voltage and output power.

[0058] In the embodiments of the present disclosure, synchronous modulation between two-stage topology structures is achieved through the internal phase shift angle of the bidirectional wireless charging system of the front-stage four-switch buck-boost converter and the rear-stage LCC-LCC compensation, without the need for cascade structure communication, thereby reducing hardware costs.

[0059] According to the embodiments of the present disclosure, the same sampling frequency is adopted for systems operating at multiple time scales, which is beneficial to reducing electromagnetic interference.

[0060] In the embodiments of the present disclosure, the new time scale can be dynamically adjusted according to the operating frequency of the system, has a wide range of applications, and has strong scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Other features, objects and advantages of the present disclosure will become more apparent by reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0062] Figure 1 The diagram is a schematic diagram of a circuit structure of a power circuit module according to an exemplary embodiment.

[0063] Figure 2 It is a structural schematic diagram of a synchronous zero voltage modulation system under a new time scale according to an exemplary embodiment.

[0064] Figure 3 The figure is a circuit structure diagram of a four-switch buck-boost converter according to an exemplary embodiment.

[0065] Figure 4 The invention is a flow chart showing a synchronous zero voltage modulation method of a cascade system according to an exemplary embodiment.

[0066] Figure 5 The figure is a schematic diagram of a structure of a power circuit for executing synchronous zero voltage modulation according to an exemplary embodiment.

[0067] Figure 6 The invention is a flow chart of a synchronous zero voltage modulation method under a new time scale according to an exemplary embodiment.

[0068] Figure 7 It is a schematic diagram of experimental results of a synchronous zero voltage modulation method of a cascade system according to an exemplary embodiment. DETAILED DESCRIPTION

[0069] The present disclosure is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present disclosure, but are not intended to limit the present disclosure in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present disclosure. These all fall within the scope of protection of the present disclosure.

[0070] Figure 1 The diagram is a schematic diagram of a circuit structure of a power circuit module according to an exemplary embodiment. Figure 2 It is a structural schematic diagram of a synchronous zero voltage modulation system under a new time scale according to an exemplary embodiment.

[0071] The present disclosure provides a synchronous zero voltage modulation system of a cascade system, comprising: a power circuit module and a modulation system.

[0072] like Figure 1 As shown, the power circuit module includes a front-stage topology structure and a rear-stage topology structure. The front-stage topology structure includes a four-switch buck-boost converter, and the rear-stage topology structure includes a bidirectional wireless charging system with LCC-LCC compensation. The four-switch buck-boost converter is connected to the bidirectional wireless charging system with LCC-LCC compensation. The four-switch buck-boost converter is used to convert the input voltage level, and the rear-stage LCC-LCC compensation bidirectional wireless charging system is used for charging.

[0073] Among them, the four-switch buck-boost converter is used to achieve the transformation of the input voltage level to match the voltage requirement of the rated power output of the subsequent LCC-LCC compensated bidirectional wireless charging system. The LCC-LCC compensated bidirectional wireless charging system is also used to charge batteries in application scenarios such as electric vehicles.

[0074] Among them, under the new time scale, the sampling frequencies of the front-stage and back-stage topological structures of the power circuit module are the same, which effectively improves the computing speed and reduces electromagnetic interference.

[0075] A four-switch buck-boost converter is used for the power circuit, and multiple time scales are introduced to provide a multi-time scale modulation mode, thereby effectively increasing the execution speed of the modulation code.

[0076] like Figure 2 As shown, the modulation system includes a voltage compensation module, a current compensation module, a current comparison module, a synchronization module, and a switch drive signal generation module. The output end of the voltage compensation module is connected to the input end of the synchronization module, the output end of the current compensation module is connected to the input end of the synchronization module, the output end of the current comparison module is connected to the input end of the synchronization module, and the output end of the synchronization module is connected to the drive signal generation module. The modulation system is used to determine the drive pulse signal of the power switch of the previous stage topology structure and the subsequent stage topology structure.

[0077] In a possible embodiment, the modulation system further includes a sampling value initialization unit, which is connected to a microprocessor (MCU) and is used to give the MCU an initial calculation value.

[0078] The output quantity of the sampling value initialization unit is input into a theoretically calculated preset value.

[0079] like Figure 2As shown, in a possible embodiment, the voltage compensation module includes a voltage regulator, the voltage regulator includes a multiplier and a proportional-integral regulator, the voltage regulator is connected to the synchronization module, and the voltage regulator is used to determine the voltage gain of the four-switch buck-boost converter.

[0080] Among them, the voltage compensation module outputs the voltage value required for the rated power output of the LCC-LCC compensated bidirectional wireless charging system, and the output of the voltage regulator is input into the synchronization module.

[0081] like Figure 2 As shown, in a possible embodiment, the current compensation module includes a current regulator, the current regulator includes a multiplier and a proportional-integral regulator, the current regulator is connected to the synchronization module, and the current regulator is used to determine whether the four-switch buck-boost converter operates under soft switching conditions.

[0082] The current regulator may also be used to determine a first switch state time value of the four-switch buck-boost converter, and the output of the current regulator is input into the synchronization module.

[0083] like Figure 2 As shown, in a possible embodiment, the current comparison module includes a first operational amplifier, the first operational amplifier is connected to the synchronization module, and the first operational amplifier is used to determine the turn-on time of the third field effect transistor of the four-switch buck-boost converter.

[0084] The output of the first operational amplifier is used as a termination mark of the third switch state of the four-switch buck-boost converter, and the output of the first operational amplifier is input into the synchronization module.

[0085] In a possible embodiment, in a possible embodiment, the modulation system also includes an RS trigger and a state selector, the output end of the current comparison module is connected to the input end of the RS trigger, the output end of the RS trigger is connected to the input end of the state selector, and the output end of the state selector is connected to the drive signal generation module.

[0086] Among them, the input quantity of the RS trigger is the termination flag of the third working state output by the current comparison module, the output quantity of the RS trigger is input into the state selector, and the RS trigger is used to determine the system operation range or mode; the output quantity of the state selector is input into the drive signal generation module, and the state selector is used to select the corresponding control strategy or parameter according to the output quantity of the RS trigger.

[0087] Figure 3 The figure is a circuit structure diagram of a four-switch buck-boost converter according to an exemplary embodiment.

[0088] like Figure 3As shown, in a possible embodiment, a four-switch buck-boost transformer includes two half-bridge structures, a DC power supply, a power inductor and an output capacitor, wherein the two half-bridge structures include four gallium nitride field-effect transistors (GaN FETs), which are respectively located on two bridge arms, and the power inductor is located between the two bridge arms.

[0089] like Figure 3 As shown, specifically, the four-switch buck-boost transformer FSBB includes a first field effect transistor S1, a second field effect transistor S2, a third field effect transistor S3, a fourth field effect transistor S4, a first DC power supply V in , a first power inductor L and a first output capacitor C f .

[0090] The output end of the first DC power supply includes a first output end "+" and a second output end "-".

[0091] The drain of the first field effect transistor is connected to the positive electrode of the first direct current power source, and the source of the first field effect transistor is connected to the first end of the first power inductor.

[0092] The source of the second field effect transistor is connected to the second end of the first power inductor, and the drain of the second field effect transistor is connected to the positive electrode of the first output capacitor.

[0093] The drain of the third field effect transistor is connected to the source of the first field effect transistor, and the source of the third field effect transistor is connected to the negative electrode of the first DC power supply.

[0094] The drain of the fourth field effect transistor is connected to the source of the second field effect transistor, and the source of the fourth field effect transistor is connected to the negative electrode of the first output capacitor.

[0095] As an example, when the first field effect transistor S1 and the fourth field effect transistor S4 are turned on, it represents a first working state, and the first working state is used to energize the first power inductor.

[0096] As another example, when the first field effect transistor S1 and the second field effect transistor S2 are turned on, it represents a second working state, and the second working state is used to simultaneously use the first DC power supply and the first power inductor to power the LCC-LCC compensated bidirectional wireless charging system.

[0097] As another example, when the second field effect transistor S2 and the third field effect transistor S3 are turned on, it represents a third working state, and the third working state is used to use the first power inductor to independently power the LCC-LCC compensated bidirectional wireless charging system.

[0098] As another example, when the third field effect transistor S3 and the fourth field effect transistor S4 are turned on, a fourth working state is represented, and the fourth working state is used to keep the current of the first power inductor constant.

[0099] like Figure 1 As shown, in a possible embodiment, a bidirectional wireless charging system with LCC-LCC compensation includes an inverter, an LCC-LCC compensation network, a primary-secondary coil, and a load DC source.

[0100] like Figure 1 As shown, specifically, the bidirectional wireless charging system with LCC-LCC compensation includes: a primary inverter FB1, a primary LCC compensation network, a primary coil, a secondary coil, a secondary LCC compensation network, a secondary active rectifier bridge FB2, a second output capacitor and a second DC power supply.

[0101] The DC input end of the primary inverter is connected to the positive electrode of the first output capacitor and the negative electrode of the first output capacitor respectively, and the AC output end of the primary inverter is connected to the input end of the primary LCC compensation network.

[0102] The output end of the primary LCC compensation network is connected to both ends of the primary coil.

[0103] The input end of the secondary side LCC compensation network is connected to the two ends of the secondary side coil, and the output end of the secondary side LCC compensation network is connected to the AC input end of the secondary side active rectifier bridge.

[0104] The DC output end of the secondary active rectifier bridge is connected to the positive electrode of the second output capacitor and the negative electrode of the second output capacitor respectively.

[0105] The positive electrode of the second DC power supply is connected to the positive electrode of the second output capacitor, and the negative electrode of the second DC power supply is connected to the negative electrode of the second output capacitor.

[0106] Figure 4 The invention is a flow chart showing a synchronous zero voltage modulation method of a cascade system according to an exemplary embodiment. Figure 5 The figure is a schematic diagram of a structure of a power circuit for executing synchronous zero voltage modulation according to an exemplary embodiment.

[0107] The present disclosure also provides a synchronous zero voltage modulation method for a cascade system, wherein a bidirectional wireless charging system with LCC-LCC compensation at a subsequent stage adopts a three-phase shift control strategy.

[0108] like Figure 4 , Figure 5 As shown, in a possible embodiment, a synchronous zero voltage modulation method of a cascade system may include S101 to S110.

[0109] S101, inputting the output voltage of the four-switch buck-boost converter of the previous stage topology structure and a preset voltage threshold into a voltage compensation module of a modulation system to determine a first input parameter.

[0110] Among them, the output voltage V Cf and the preset voltage threshold V ref The difference is used as the input of the voltage regulator, and the voltage regulator outputs the second working state time value t of the four-switch buck-boost converter through the PI link of the proportional-integral regulator. M2_PI , and use it as the first input parameter of the synchronization module.

[0111] S102, taking the output voltage of the four-switch buck-boost converter as a second input parameter.

[0112] Among them, the output voltage V Cf As the second input parameter of the synchronization module.

[0113] S103: Input the output current of the primary inverter of the LCC-LCC compensated bidirectional wireless charging system and a preset first current threshold into a current compensation module of the modulation system to determine a third input parameter.

[0114] Among them, the output current of the primary inverter of the LCC-LCC compensated bidirectional wireless charging system is i p and the preset first current threshold is -I p_ZVS The difference is used as the input of the current regulator. The current regulator outputs the judgment result of whether the primary inverter works in the synchronous zero voltage state through the PI link of the proportional integral regulator, and uses it as the third input parameter of the synchronization module.

[0115] Among them, if i p >-I p_ZVS Indicates that the primary inverter is not operating in the synchronous zero voltage state, and the external phase shift angle γ needs to be adjusted; if i p ≤-I p_ZVS It means that the primary inverter operates in synchronous zero voltage state.

[0116] S104, determining an inner phase shift angle according to a full modal cycle of a bidirectional wireless charging system with a four-switch buck-boost converter and LCC-LCC compensation, where the inner phase shift angle is used as a fourth input parameter.

[0117] Among them, when the operating frequencies of the four-switch buck-boost converter and the LCC-LCC compensated bidirectional wireless charging system are different, switch S1 and switch Q 11The driving pulse is used as a reference moment, and there is an internal phase shift angle β. In a full-modal cycle, the least common multiple of the working cycles of the four-switch buck-boost converter and the LCC-LCC compensated bidirectional wireless charging system is taken as the full-modal cycle. The internal phase shift angle is unique for a single fast cycle or a single slow cycle.

[0118] S105 , inputting the first power inductor current value and the preset second current threshold into a current comparison module to determine a fifth input parameter.

[0119] Wherein, the first power inductor current value i L and the preset second current threshold -I L_ZVS The first operational amplifier is input, and the output result of the first operational amplifier is used as the termination mark of the third working state. M3_End , and also serves as the fifth input parameter of the synchronization module.

[0120] As an example, in the first operational amplifier, if i L ≤-I L_ZVS , then the third working state is terminated; if i L >-I L_ZVS , the third working state continues to maintain the original state.

[0121] S106: Use the output voltage of the first DC power supply as a sixth input parameter.

[0122] Among them, the output voltage of the first DC power supply is V in .

[0123] S107, taking the external shift phase angles of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system as the seventh input parameter.

[0124] Among them, the outward shift phase angle of the primary side and the secondary side of the bidirectional wireless charging system with LCC-LCC compensation is γ.

[0125] S108, taking the operating frequency of the previous-stage topological structure as an eighth input parameter, and taking the operating frequency of the subsequent-stage topological structure as a ninth input parameter.

[0126] Among them, the operating frequency of the four-switch buck-boost converter in the previous topology is f M The operating frequency of the bidirectional wireless charging system with LCC-LCC compensation in the post-stage topology is f N .

[0127] S109, input the first input parameter, the second input parameter, the third input parameter, the fourth input parameter, the fifth input parameter, the sixth input parameter, the seventh input parameter, the eighth input parameter, and the ninth input parameter into a synchronization module to determine the first working state time value, the second working state time value, the third working state time value, and the actual outward shift phase angle of the primary side and the secondary side of the bidirectional wireless charging system with LCC-LCC compensation.

[0128] Among them, the time value of the first working state is t M1 , the second working state time value t M2 , the actual outward shift phase angle γ _opt .

[0129] S110, input the first working state time value, the second working state time value, the third working state time value, and the actual external shift phase angle of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system into a drive signal generation module to determine the pulse signal of the power switch of the four-switch buck-boost converter and the LCC-LCC compensated bidirectional wireless charging system.

[0130] Among them, the drive signal generation module outputs v gs1 ~v gs4 represents the switch drive pulse signal of the front-stage four-switch buck-boost converter, v gs11 ~v gs14 A pulse signal representing the power switch of a bidirectional wireless charging system with post-stage LCC-LCC compensation.

[0131] The pulse signal of the power switch is used to determine the turn-on and turn-off time of each power switch.

[0132] Figure 6 The invention is a flow chart of a synchronous zero voltage modulation method under a new time scale according to an exemplary embodiment.

[0133] like Figure 6 As shown, in a possible embodiment, S109 may include S201 to S207.

[0134] S201, initializing a second input parameter, a sixth input parameter, a fourth input parameter, a seventh input parameter, a minimum sampling current value of a first power inductor, and an inverter current value of a bidirectional wireless charging system with LCC-LCC compensation.

[0135] Among them, the second input parameter V is initialized cf , the sixth input parameter V in , the fourth input parameter β, the seventh input parameter γ, the minimum sampling current value I of the first power inductor L0 , the inverter current value I of the bidirectional wireless charging system with LCC-LCC compensation p0 .

[0136] Inverter current value I of bidirectional wireless charging system with LCC-LCC compensation p0 For the switch Q 11 The sampling current value of the inverter current when closed.

[0137] S202: Define a new time scale and full modal period according to the eighth input parameter and the ninth input parameter.

[0138] According to the eighth input parameter and the ninth input parameter, the duty cycle of the four-switch buck-boost converter and the duty cycle of the bidirectional wireless charging system with LCC-LCC compensation are determined: T M =1 / f M and T N =1 / f N , define a new time scale as T m =min_com{T M ,T N}, define the full modal period as T max_com =max_com{T M ,T N}.

[0139] In the full modal period T max_com In the figure, for each working cycle of the bidirectional wireless charging system with LCC-LCC compensation in the subsequent stage, there is an internal phase shift angle f(β)=β, f(β)=β+2π,….

[0140] The new time scale can be dynamically adjusted according to the operating frequency of the system, and has a wide range of applications and strong scalability.

[0141] In a possible embodiment, according to the minimum sampling current value I of the first power inductor L0 and the preset second current threshold -I L_ZVS , to determine whether the first power inductor reaches the synchronous zero voltage state. L0 ≤-I L_ZVS When I L0 >-I L_ZVS , indicating that the first power inductor reaches the synchronous zero voltage state.

[0142] S203: Use the first input parameter output by the voltage compensation module as the second working state time value.

[0143] The first input parameter is t M2_PI , as the second working state time value t M2 .

[0144] S204, when the four-switch buck-boost converter is in a buck operation mode, determine a first operation state time value according to a preset first expression and a new time scale.

[0145] The first expression is preset as:

[0146] t M1 =t M1_ZVS +(n+a)Τ m +f(β);

[0147] n=0,1,2,...;0 <a<1

[0148] Among them, t M1 Indicates the time value of the first working state, t M1_ZVS represents the minimum current required for the four-switch buck-boost converter to achieve synchronous zero voltage, and n represents t M1 Duration from t M1_ZVS Increased T m The number of time scales, a represents the realization of t M1 Accurately calculated control quantity, T m represents the new time scale, and f(β) represents the internal phase shift angle of the bidirectional wireless charging system between the front-stage four-switch buck-boost converter and the back-stage LCC-LCC compensation.

[0149] in,

[0150] t M1_ZVS =4C oss L / t d +(1+σ)t d ,σ≤1

[0151] Among them, t M1_ZVS represents the minimum current required for the four-switch buck-boost converter to achieve synchronous zero voltage, L represents the first power inductor, t d represents the dead time of the trigger pulse of the upper and lower power switches in the same bridge arm, and σ represents the output voltage V of the four-switch buck-boost converter Cf The output voltage V of the first DC power supply in ratio.

[0152] In this disclosure, f(β) represents a global variable and does not directly participate in the operation. N The instructions are calculated and used for synchronization. The internal phase shift angle of the bidirectional wireless charging system with four-switch buck-boost converter at the front stage and LCC-LCC compensation at the back stage is used to achieve synchronous modulation between the two-stage topology structures, without the need for cascade structure communication, thus reducing hardware costs.

[0153] Parameter n is uniquely corresponding to the output power and is stored in the lookup table LUT. Parameter a is 0 <a<1。

[0154] Parameter n is used to realize the first working state time value t M1 The parameter a is used to ensure the first working state time value t M1 accuracy.

[0155] By quickly searching for parameter n and parameter a, the execution time of full-mode periodic modulation is reduced. By establishing a two-dimensional lookup table of input voltage and output power, the execution of the modulation strategy is realized and the storage space size is reduced.

[0156] S205: Determine the third working state time value according to the volt-second balance principle and the second working state time value.

[0157] t M3 =(t M1_ZVS +(n+a)Τ m ) / σ+(1-σ)t M2 / σ,σ≤1

[0158] Among them, t M3 Indicates the time value of the third working state, t M2 Indicates the time value of the second working state.

[0159] S206, when the first power inductor does not reach the synchronous zero voltage state, if the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is less than the preset third current threshold, determine that the seventh input parameter is the actual external shift phase angle of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system.

[0160] Among them, the inverter current value of the bidirectional wireless charging system with LCC-LCC compensation is represented by I p0 , the preset third current threshold represents -I p_ZVS .

[0161] The following formula is used to calculate the minimum current required for the LCC-LCC compensated bidirectional wireless charging system to achieve synchronous zero voltage:

[0162] I p_ZVS =2*2σC oss V in / t d

[0163] Among them, I p_ZVS represents the minimum current required for the LCC-LCC compensated bidirectional wireless charging system to achieve synchronous zero voltage, V in represents the output voltage of the first DC power supply, t d Indicates the dead time of the trigger pulse of the upper and lower power switches in the same bridge arm.

[0164] If I p0 ≤-Ip_ZVS , keep the original external shift phase angle as the actual external shift phase angle, that is, the seventh input parameter.

[0165] S207, when the first power inductor has not reached the synchronous zero voltage state, if the inverter current value of the bidirectional wireless charging system with LCC-LCC compensation is not less than the preset third current threshold, a new external phase shift angle is iteratively determined according to a preset step size until the inverter current value of the bidirectional wireless charging system with LCC-LCC compensation is less than the preset third current threshold, and the new external phase shift angle is determined as the actual external phase shift angle of the primary and secondary sides of the bidirectional wireless charging system with LCC-LCC compensation.

[0166] Among them, if I p0 >-I p_ZVS , iteratively determine the new external phase angle γ value with a preset step size Δγ, and ensure that γ∈Z ZVS , until the new sampling value of the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is less than the preset third current threshold, that is, I p0 ≤-I p_ZVS , and the corresponding new external phase shift angle at this moment is taken as the actual external phase shift angle γ value, that is, the external phase shift angle γ value of the LCC-LCC compensated bidirectional wireless charging system during synchronous zero voltage operation.

[0167] The new external phase angle γ value is determined iteratively with a preset step size Δγ as follows:

[0168] γ n+1 =γ n +Δγ; and γ∈Z zvs

[0169] The preset step size may be ±0.01°.

[0170] By judging the inverter current value of the LCC-LCC compensated bidirectional wireless charging system and the preset third current threshold, the external shift phase angle of the LCC-LCC compensated bidirectional wireless charging system is adjusted to ensure that the subsequent LCC-LCC compensated bidirectional wireless charging system operates in a synchronous zero voltage area.

[0171] In a possible embodiment, a synchronous zero voltage modulation method for a cascade system may further include S111.

[0172] S111, determining a fourth working state time value according to a working cycle of the four-switch buck-boost converter, a first working state time value, a second working state time value, and a third working state time value.

[0173] t M4 =T M -t M1 -t M2 -tM3

[0174] Among them, t M4 Indicates the time value of the fourth working state, T M represents the duty cycle of the four-switch buck-boost converter, t M1 Indicates the time value of the first working state, t M3 Indicates the time value of the third working state, t M2 Indicates the time value of the second working state.

[0175] Step S111 of the present disclosure is performed after step S109 , and the fourth working state time value is also input into the driving signal generating module to generate a pulse signal of the power switch.

[0176] In one possible embodiment, when the gain of the front-stage four-switch buck-boost converter is greater than 1:

[0177] The first switch state time value is:

[0178] When σ>1, t M1 =σ(t M3_ZVS +(n+a)Τ m )-(1-σ)t M2 / σ

[0179] The third switch state time value is:

[0180] t M3_ZVS =4C oss L / t d +(1+σ)t d / σ,σ>1

[0181] Through the above technical solution, a four-switch buck-boost converter is used for the power circuit, and multiple time scales are introduced to provide a modulation method with multiple time scales, thereby effectively increasing the execution speed of the modulation code.

[0182] In a possible embodiment, the synchronous zero voltage modulation method of the cascade system provided by the present disclosure is adopted, and the system parameters are set as follows:

[0183] Input voltage: 100-400V, DC;

[0184] Output power: hundreds of watts to 2.5kW;

[0185] Working frequency: 40kHz for front stage, 85kHz for rear stage;

[0186] Power inductor: 55μH;

[0187] Transmitting coil self-inductance L1: 75.7μH;

[0188] Receiving coil self-inductance L1: 77.5μH;

[0189] Primary series compensation inductor L p :41.5μH;

[0190] Primary side series compensation capacitor C1: 102.5nF;

[0191] Primary parallel compensation capacitor C p : 83.7nF;

[0192] Secondary side series compensation inductor L s :41.5μH;

[0193] Secondary side series compensation capacitor C2: 97.4nF;

[0194] Secondary side parallel compensation capacitor C s :84.5nF;

[0195] DSP:TMS320F28335.

[0196] The first bus capacitor C f : 100μF;

[0197] The second bus capacitor C o : 100μF;

[0198] SiC FET S1~S4: C3M0021120K, C oss =180pF@(Tc=25℃,V DS =1000V),

[0199] R DS(on) =38mΩ@(V GS =15V,I D =50A,T J =175℃)

[0200] Initial outward shift phase angle γ: 90°;

[0201] γ iteration step: ±0.01°;

[0202] Z ZVS Range: 80.4°~96.2°.

[0203] Figure 7 It is a schematic diagram of experimental results of a synchronous zero voltage modulation method of a cascade system according to an exemplary embodiment.

[0204] The synchronous zero voltage modulation method of the cascade system provided by the present disclosure is adopted, such as Figure 7As shown, the gate-source voltage waveforms of S1 and S2, the drain-source voltage waveforms, and the inverter voltage and inverter current waveforms of the subsequent IPT system of the corresponding front-stage four-switch buck-boost converter in the three working modes of Buck, Boost, and equal are shown.

[0205] From the above content, it can be concluded that the synchronous zero voltage modulation method of the cascade system implemented by the present disclosure realizes synchronous zero voltage ZVS operation within a wide input voltage and output power range of multiple time scales, effectively reducing the switching loss of the system.

[0206] Based on the same concept as above, in another embodiment of the present disclosure, an electronic device is also provided, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, and the processor is used to execute a synchronous zero voltage modulation method of a cascade system when executing the program.

[0207] Optionally, the memory is used to store programs; the memory may include volatile memory (English: volatile memory), such as random-access memory (English: random-access memory, abbreviated: RAM), such as static random-access memory (English: static random-access memory, abbreviated: SRAM), double data rate synchronous dynamic random access memory (English: Double Data Rate Synchronous Dynamic Random Access Memory, abbreviated: DDR SDRAM), etc.; the memory may also include non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory). The memory is used to store computer programs (such as applications, functional modules, etc. that implement the above method), computer instructions, etc., and the above computer programs, computer instructions, etc. can be partitioned and stored in one or more memories. And the above computer programs, computer instructions, data, etc. can be called by the processor.

[0208] The above-mentioned computer programs, computer instructions, etc. may be stored in one or more memories in partitions, and the above-mentioned computer programs, computer instructions, data, etc. may be called by a processor.

[0209] The processor is used to execute the computer program stored in the memory to implement the various steps in the method involved in the above embodiment. For details, please refer to the relevant description in the above method embodiment.

[0210] The processor and the memory may be independent structures or integrated structures. When the processor and the memory are independent structures, the memory and the processor may be coupled and connected via a bus.

[0211] In an embodiment of the present disclosure, a non-temporary computer-readable storage medium is also provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of a synchronous zero-voltage modulation method for a cascade system in any of the above embodiments are implemented.

[0212] Those skilled in the art will appreciate that the embodiments of the present disclosure may be provided as methods, systems, or computer program products. Therefore, the present disclosure may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present disclosure may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0213] The present disclosure is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present disclosure. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0214] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0215] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0216] Although the preferred embodiments of the present disclosure have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present disclosure.

[0217] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalents, the present disclosure is also intended to include these modifications and variations.

Claims

1. A synchronous zero voltage modulation system of a cascade system, characterized in that: include: Power circuit modules and modulation systems; The power circuit module includes a front-stage topology structure and a rear-stage topology structure, the front-stage topology structure includes a four-switch buck-boost converter, the rear-stage topology structure includes a LCC-LCC compensated bidirectional wireless charging system, the four-switch buck-boost converter is connected to the LCC-LCC compensated bidirectional wireless charging system, the four-switch buck-boost converter is used to convert the input voltage level, and the LCC-LCC compensated bidirectional wireless charging system is used for charging; The modulation system includes a voltage compensation module, a current compensation module, a current comparison module, a synchronization module, and a switch drive signal generation module. The output end of the voltage compensation module is connected to the input end of the synchronization module, the output end of the current compensation module is connected to the input end of the synchronization module, the output end of the current comparison module is connected to the input end of the synchronization module, and the output end of the synchronization module is connected to the drive signal generation module. The modulation system is used to determine the drive pulse signal of the power switch of the previous stage topology structure and the subsequent stage topology structure.

2. The synchronous zero voltage modulation system of the cascade system according to claim 1, characterized in that: The voltage compensation module includes a voltage regulator, the voltage regulator includes a multiplier and a proportional integral regulator, the voltage regulator is connected to the synchronization module, and the voltage regulator is used to determine the voltage gain of the four-switch buck-boost converter; The current compensation module includes a current regulator, the current regulator includes a multiplier and a proportional integral regulator, the current regulator is connected to the synchronization module, and the current regulator is used to determine whether the four-switch buck-boost converter operates under soft switching conditions; The current comparison module includes a first operational amplifier, which is connected to the synchronization module and is used to determine the turn-on time of the third field effect transistor of the four-switch buck-boost converter.

3. The synchronous zero voltage modulation system of the cascade system according to claim 1, characterized in that: The four-switch buck-boost transformer includes a first field effect transistor, a second field effect transistor, a third field effect transistor, a fourth field effect transistor, a first DC power supply, a first power inductor, and a first output capacitor; The drain of the first field effect transistor is connected to the positive electrode of the first DC power supply, and the source of the first field effect transistor is connected to the first end of the first power inductor; The source of the second field effect transistor is connected to the second end of the first power inductor, and the drain of the second field effect transistor is connected to the positive electrode of the first output capacitor; The drain of the third field effect transistor is connected to the source of the first field effect transistor, and the source of the third field effect transistor is connected to the negative electrode of the first DC power supply; The drain of the fourth field effect transistor is connected to the source of the second field effect transistor, and the source of the fourth field effect transistor is connected to the negative electrode of the first output capacitor.

4. The synchronous zero voltage modulation system of the cascade system according to claim 3, characterized in that: When the first field effect transistor and the fourth field effect transistor are turned on, a first working state is represented, and the first working state is used to energize the first power inductor; When the first field effect transistor and the second field effect transistor are turned on, a second working state is represented, and the second working state is used to simultaneously use the first DC power supply and the first power inductor to power the LCC-LCC compensated bidirectional wireless charging system; When the second field effect transistor and the third field effect transistor are turned on, a third working state is represented, and the third working state is used to use the first power inductor to power the LCC-LCC compensated bidirectional wireless charging system; When the third field effect transistor and the fourth field effect transistor are turned on, a fourth working state is represented, and the fourth working state is used to keep the current of the first power inductor constant.

5. The synchronous zero voltage modulation system of the cascade system according to claim 3, characterized in that: The LCC-LCC compensated bidirectional wireless charging system includes a primary inverter, a primary LCC compensation network, a primary coil, a secondary coil, a secondary LCC compensation network, a secondary active rectifier bridge, a second output capacitor and a second DC power supply; The DC input end of the primary inverter is connected to the positive electrode of the first output capacitor and the negative electrode of the first output capacitor respectively, and the AC output end of the primary inverter is connected to the input end of the primary LCC compensation network; The output end of the primary LCC compensation network is connected to two ends of the primary coil; The input end of the secondary side LCC compensation network is connected to the two ends of the secondary side coil, and the output end of the secondary side LCC compensation network is connected to the AC input end of the secondary side active rectifier bridge; The DC output end of the secondary active rectifier bridge is respectively connected to the positive electrode of the second output capacitor and the negative electrode of the second output capacitor; The positive electrode of the second DC power supply is connected to the positive electrode of the second output capacitor, and the negative electrode of the second DC power supply is connected to the negative electrode of the second output capacitor.

6. A synchronous zero voltage modulation method for a cascade system, characterized in that: include: The output voltage of the four-switch buck-boost converter of the previous topology structure and the preset voltage threshold are input into the voltage compensation module of the modulation system to determine the first input parameter; Using the output voltage of the four-switch buck-boost converter as a second input parameter; Inputting the output current of the primary inverter of the LCC-LCC compensated bidirectional wireless charging system and a preset first current threshold into the current compensation module of the modulation system to determine a third input parameter; Determine an inner phase shift angle according to a full modal cycle of the bidirectional wireless charging system of the four-switch buck-boost converter and the LCC-LCC compensation, wherein the inner phase shift angle is used as a fourth input parameter; Inputting the first power inductor current value and the preset second current threshold into the current comparison module to determine a fifth input parameter; Using the output voltage of the first DC power supply as a sixth input parameter; The external phase shift angles of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system are used as the seventh input parameter; The operating frequency of the previous topology structure is used as an eighth input parameter, and the operating frequency of the subsequent topology structure is used as a ninth input parameter; Input the first input parameter, the second input parameter, the third input parameter, the fourth input parameter, the fifth input parameter, the sixth input parameter, the seventh input parameter, the eighth input parameter, and the ninth input parameter into a synchronization module to determine a first working state time value, a second working state time value, a third working state time value, and an actual external shift phase angle of the primary side and the secondary side of the bidirectional wireless charging system with LCC-LCC compensation; The first working state time value, the second working state time value, the third working state time value, and the actual external shift phase angles of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system are input into a driving signal generation module to determine the pulse signals of the power switches of the four-switch buck-boost converter and the LCC-LCC compensated bidirectional wireless charging system.

7. The method according to claim 6, characterized in that The step of inputting the first input parameter, the second input parameter, the third input parameter, the fourth input parameter, the fifth input parameter, the sixth input parameter, the seventh input parameter, the eighth input parameter, and the ninth input parameter into the synchronization module to determine the first working state time value, the second working state time value, the third working state time value, and the actual external shift phase angle of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system, comprises: Initialize the second input parameter, the sixth input parameter, the fourth input parameter, the seventh input parameter, the minimum sampling current value of the first power inductor, and the inverter current value of the LCC-LCC compensated bidirectional wireless charging system; Defining a new time scale and a full modal period according to the eighth input parameter and the ninth input parameter; When the first power inductor reaches a synchronous zero voltage state, using the first input parameter output by the voltage compensation module as the second working state time value; When the four-switch buck-boost converter is in a buck working mode, determining the first working state time value according to a preset first expression and the new time scale; Determine the third working state time value according to the volt-second balance principle and the second working state time value; When the first power inductor does not reach the synchronous zero voltage state, if the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is less than a preset third current threshold, determining that the seventh input parameter is an actual external shift phase angle of the primary side and the secondary side of the LCC-LCC compensated bidirectional wireless charging system; When the first power inductor has not reached the synchronous zero voltage state, if the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is not less than the preset third current threshold, a new inner phase shift angle is iteratively determined according to a preset step size until the inverter current value of the LCC-LCC compensated bidirectional wireless charging system is less than the preset third current threshold, and the new outer phase shift angle is determined as the actual outer phase shift angle of the primary and secondary sides of the LCC-LCC compensated bidirectional wireless charging system.

8. The method according to claim 7, characterized in that The method further comprises: A fourth working state time value is determined according to the working cycle of the four-switch buck-boost converter, the first working state time value, the second working state time value and the third working state time value.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 6 to 8 are implemented.

10. An electronic device, characterized in that: include: a memory having a computer program stored thereon; A processor, configured to execute the computer program in the memory to implement the steps of the method according to any one of claims 6 to 8.

Images