Parameter Design of a Three-Level Converter Based on Series-Connected HV-IGBTs

Although the maximum collector-emitter voltage of a high-voltage insulated-gate bipolar transistor (HV-IGBT) reaches 3300 V or higher, it still cannot satisfy the requirements of some high-voltage high-power converters. Applying power semiconductor devices in series connection can effectively improve the voltage rating and power rating of a power electronic converter. The key issue of device series connection is voltage balancing in static switching state and dynamic switching state. In this paper, a three-level converter based on series-connected HV-IGBTs is presented, its voltage-balancing subcircuits are analyzed, and the parameter design method for the converter is proposed. During the design process, key performance indexes of the series connection circuit, such as the voltage-balancing effect, loss of the voltage-balancing circuit, switching loss, and switching time, are comprehensively considered. Moreover, component parameters of the three-level converter are calculated considering the influence of the voltage-balancing circuit. The proposed parameter design method is applied in the development of a three-level HV-IGBT (4500 V/600 A) series connection test platform with 10 000-V rated dc-link voltage. Experimental results verify the validity of the proposed method.