FAULT CHARACTERISTICS ANALYSIS OF DC DISTRIBUTION NETWORK BASED ON POWER ELECTRONIC TRANSFORMER

摘要

In recent years, power electronic transformer (PET) that can realize various functions such as voltage transformation, electrical isolation, power regulation and control, and new energy access has been gradually applied in DC distribution networks as a new type of converter. The power electronic transformer's structure is different from that of the traditional voltage source converter, the fault characteristics no longer meet the three-stage characteristics. Therefore, it is necessary to study the fault characteristics of the power electronic transformer. Based on the Suzhou Tongli DC distribution network project, a multi-port power electronic transformer (AC10kV/DC±750V/DC±375V) is established in this paper. The fault characteristics of the two DC ports is analysed respectively. The PSCAD simulation results verify the accuracy of the analysis result of fault characteristics.