Design of a High-Power MC-WPT System for Variable Distance Based on Modular Parallel Technology

In recent years, magnetically coupled wireless power transmission (MC-WPT) technology has gained significant research results, and the degree of technology has increased dramatically. When charging an EV, the actual position of the EV is affected by the subjective operation of the driver, and the height of the chassis is also affected by the weight of the vehicle, which results in differences in the transmission distance of the EV each time the EV is charged, and there may be lateral offset, which prevent the EV from charging with high efficiency at the rated position. This paper designed a high-power MC-WPT system for variable distance based on modular parallel technology for EVs. The designed system adopts a circuit topology with multiple inverters connected in parallel and multiple rectifier bridges connected in parallel to reduce the current stress of switching devices and increase the power capacity of the whole MC-WPT. The frequency modulation control strategy based on active and reactive power detection is used to suppress the effect of self-inductance variation, and the secondary active bridge phase-shift control is used to suppress the power variation caused by mutual inductance variation to realize the constant voltage control at the output. Finally, a high energy efficiency of 12kW, more than 85%, is realized in simulation and experimental verification.