基于耦合外部并联谐振支路的多相逆变器均流方法

A novel passive current sharing method for a multiphase wireless power transfer (WPT) system is proposed in this letter. For an N-phase inverter, there would be N compensating inductors in the inductor–capacitor–capacitor series (LCC-S) compensated WPT system. The proposed scheme introduces N external parallel resonant branches coupled with these N compensating inductors. In this way, an extremely large impedance is introduced in each loop of the circulating currents so as to balance the phase currents. No additional passive components with the rated power level are added to the power transfer channel. The proposed method employs two coupled inductors, which is easy to realize. Two new integrated structures for coupled inductors are introduced. The mathematical model and the current sharing principle of the proposed method are analyzed in detail. A 1.6-kW LCC-S compensated WPT experimental prototype with a four-phase inverter and the experimental results verify the effectiveness of the proposed current sharing method.