Isolation system with wireless power transfer for multiple gate driver supplies of a medium voltage inverter

In this paper, a multiple wireless power transfer system for multiple gate driver supplies of a medium voltage inverter is developed. The proposed isolation system achieves a galvanic isolation with an air-gap of 50 mm using a wireless power transfer with magnetic resonance coupling. It easily respects the standard of galvanic isolation, which is established by International electrotechnical commission (IEC). Moreover, the power is supplied from one transmitting board to six gate drivers without a solid magnetic core. In this paper, the isolation system is developed and tested. It is clarified that the isolation system transmits power of not less than 300 mW to each gate drivers beyond an air-gap. However, sum of the output power of the each receiving board are limited up to approximately 3.5 W because of a voltage drop in the equivalent series resistances of the transmission coils.