Mega-hertz High-power WPT system with Parallel-connected inverters using current balance circuit

This paper proposes a new current balancer for the megahertz WPT system. The proposed balancer achieves a current balance between the parallel connection inverter on the transmission side of the WPT system. The balancer consists of two transformers without any additional control to achieve a current balance. The output side of a conventional balancer is not isolated from the input side of the balancer. The proposed balancer isolates the output side and the input side of the balancer. A turn ratio of two transformers is derived by magnet flux under the current balancing condition. Furthermore, the proposed balancer also has the capability of the impedance matching. The leakage inductance of two transformers is applied to achieve an impedance matching with an additional capacitor. The experimental results reveal that the current balance is achieved even if the phase of the output voltage of each inverter has a difference of approximately 8 ns.