Series Connection of IGBTs With Self-Powering Technique and 3-D Topology

This paper analyzes the effects of parasitic capacitances in the series connection of insulated-gate bipolar transistors (IGBTs) on their voltage sharing. These parasitics exist naturally due to gate driver interconnects and power circuit physical architecture. Two solutions, which can be combined, are proposed to minimize these effects in order to achieve a better voltage balancing. The first one is based on gate driver self-powering technique. The second one is based on a vertical structure assembly of IGBTs connected in series. The performance offered by these two complementary solutions is investigated and validated on a series connection of three IGBTs in a chopper converter. Both simulation and experimental results show the effectiveness of our approaches.