Development of a discrete energy injection inverter for contactless power transfer

This paper presents a new DC-AC resonant inverter for contactless power transfer systems based on a discrete energy injection technology. The proposed inverter has a simple structure, low component count and is easy to control. Owing to the advances of the control strategy, the switches of the proposed DC-AC inverter operate at lower switching frequencies than traditional inverters that supply the required high frequency output track current for contactless power transfer applications. Because of the ZCS (zero current switching) operation, the switching losses and EMI of the proposed inverter are also reduced. Both simulation and experimental results have shown that the proposed resonant inverter has very fast and smooth start-up transient performance, and the magnitude of the output current is fully controllable.