Research On MC-WPT System With Bridge Compensation Network For Low Voltage And High Current Input Environment

Wireless Power Transfer(WPT)technology is a technology that comprehensively utilizes power electronics,electromagnetic field theory,and control theory.This technology achieves wireless transmission of electrical energy through energy medium.Magnetic Coupled Wireless Power Transfer(MC-WPT)technology uses high frequency alternating magnetic field as power transfer medium based on magnetic coupling resonance principle.It has the advantages of high energy transmission power and low cost,so it has received extensive attention from experts and scholars.In the MC-WPT system,the magnitude of the current in the resonant coil affects the transmission performance of the system.In a system with low-voltage and high-current input characteristics such as PV generation MC-WPT system,it need to increase DC-DC boost circuit for larger output power.Another way is to use resonant compensation network with larger gain.However,increasing the DC-DC boosting section will not only bring additional design costs,but also increase the voltage stress of the switching devices in the MC-WPT system.The use of a high-gain resonant compensation network increases the electrical stress of the capacitive and inductive components in the system while increasing the resonant current.Therefore,there is a mutual constraint between electrical stress and system power.In order to get better application of MC-WPT system in low voltage and high current input environment,the problem of excessive electrical stress of the device needs to be solved urgently.In view of the above problems,this paper aims to reduce the stress of components and improve the transmission performance of the system and combines the characteristics of MC-WPT system under low voltage and high current input environment.In this paper,the transmission characteristics of two-sided LCC and LCL-S resonant networks with large gains are analyzed,and the law between output power and component stress is obtained.On this basis,the paper proposes a bridge resonance compensation network.Its structure is similar to the classic full-bridge inverter topology,except that the switch is replaced by a capacitive inductor.The special connection of capacitors and inductors in the resonant compensation network makes the MC-WPT system have lower component stress.Considering that the design of a resonant compensation network aiming at reducing component stress requires both system transmission performance,this paper presents a parameter design method.According to the bridge compensation network and its parameter design method proposed in the previous paper,this paper establishes the simulation model on Matlab/Simulink platform.The results show that the bridge compensation network can achieve greater power transfer with lower electrical stress.Finally,an MC-WPT system with a DC input voltage of 10 V,a power of approximately 238 W,and an efficiency of approximately 80% was built.The transmission performance and component stress of the system were measured and analyzed.The experimental results were consistent with the simulation and theoretical analysis.The experimental results prove the feasibility and practicability of the bridge compensation network and system parameter design method.