A practical investigation of a high power, bidirectional charging system for electric vehicles

In the last few years, there has been a very high interest in inductive charging systems for electric vehicles, as they have many advantages compared to cable connected solutions. The power rating of most of these systems is kept around 3.3 kW, which leads to very long charging times. The following paper presents an inductive charging system rated for a high power level of 22 kW. A series-series resonant circuit proves to be very efficient, as high circulating currents, present in parallel compensated systems, are avoided. To reduce switching and conduction losses, but also the size of the whole system, SiC-MOSFETs are used. For the control of the inductive transmission path, several methods are presented and a pulse density modulation (PDM) is investigated and experimentally evaluated.