Voltage Sharing Circuit of Current-Source Actively Commutated Converter for HVDC

Current-source actively commutated converter (ACC) provides a new solution for high voltage direct current (HVDC) transmission system. However, Power semiconductor devices in ACC need to withstand both forward and reverse voltage. An insulated-gate bipolar transistor (IGBT) and a diode are usually used in series as a combined reverse block device. Therefore, the diode and IGBT need to be configured with a voltage sharing circuit separately according to the traditional method. This requires a lot of auxiliary components in large-scale series. In this paper, the voltage and current stress of ACC are analyzed, and then the voltage sharing circuits of diode and IGBT are integrated to reduce the number of components. Simulation in Saber shows that the proposed method has good performance of static and dynamic voltage sharing. The results show that the proposed method can reduce 25% of components compared with the traditional method.