Abstract：Solid state transformer (SST), as one of the most important equipment for smart grid application, will play a more important role in the future power system. In order to solve some issues existed in the three-phase cascaded modular SST, such as the complexity of the topology, difficulty in controlling, voltage and power unbalance of each H-bridge module,a simple three-phase SST topology based on high-voltage silicon carbide (SiC) power semiconductor device is adopted in this paper. The simple topology revitalizes the traditional topology and has a great practical prospect. Its mathematical model and normal control strategy are established and analyzed in this paper, and then a control strategy under unbalanced grid voltages by suppressing the negative-sequence currents at the grid side of SST is presented. Simulation results in PSIM software have verified the effectiveness of the two control strategies. Finally the experiment platform based on SiC devices was built, and the front-end rectifier was verified by experiment results.
于程皓, 王玉斌, 李厚芝. 基于高压碳化硅器件的三相固态变压器拓扑及其在电网电压不平衡下的控制[J]. 电工技术学报, 2017, 32(增刊2): 111-118.
Yu Chenghao, Wang Yubin, Li Houzhi. The Three-Phase Solid State Transformer Topology Based on High-Voltage SiC Device and Control Strategy Under Unbalanced Grid Voltages. Transactions of China Electrotechnical Society, 2017, 32(增刊2): 111-118.
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