Circulating Current Minimization in MC-WPT System with Multiple Inverter Modules Operate in Parallel

Abstract

The magnetic coupled wireless power transfer (MCWPT) system with multiple inverter modules operated in parallel is investigated in this paper. The circulating current among the inverter modules is analyzed first. A novel topology with a control scheme is proposed aiming to minimize the circulating current among the inverter modules based on the active and reactive current decomposition. In the proposed circulating minimization method, there is only one loop which is proved to be a phase control loop. It is shown that the circulating current minimization can be achieved if the phase of all the modules output voltages are the same. Performance is verified with both simulations and experiments on a prototype MCWPT system where two resonant inverter modules are operated in parallel. Finally, a conclusion is given.