Single-source Cascaded Multilevel Inverter for Magnetic Coupling Wireless Power Transfer Systems

In magnetic coupling wireless power transfer (MC-WPT) systems, the power capacity of the high frequency inverter determines the amount of the output power. With the development of MC-WPT technology for high power applications, traditional H-bridge inverters can no longer meet the power requirement of the system due to the capacity limitation of switching devices. To this end, this paper proposes a single-source cascaded multilevel inverter, which consists of multiple H-bridge inverters and charging switching networks. It can improve the output voltage and reduce its total harmonic distortion (THD) without increasing the voltage stress of switching devices. Compared with the existing multi-level inverters, the proposed inverter does not have problems such as multiple input source and voltage imbalance of capacitors. This paper introduces the topology and working principle of the proposed inverter, and calculates its output voltage and current. Then its capacitance parameters and modulation strategy are designed. Finally, a simulation model of MC-WPT system based on the proposed inverter is built in Matlab/Simulink simulation platform to verify the feasibility of the proposed inverter.