DC Transformer Based on Switched Capacitor in High and Medium Voltage DC Power System
Li Jianguo1, Zhao Biao2, Song Qiang2, Liu Wenhua2
1. School of Automation Beijing Information Science and Technology University Beijing 100192 China; 2. State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University Beijing 100084 China;
Abstract：A scheme of dc transformer based on switched capacitor applied in high and medium DC power system was presented and analyzed in this paper. When the DC voltage ratio of primary and secondary voltage sides fails to match the voltage ratio of transformer, the voltage matching of high frequency link can be achieved by adding a short circuit conduction process of the primary full bridge, thereby improving the current stress of the switches and the efficiency of the system. The proposed scheme can also be functioned as a DC circuit breaker. It can remove a DC-side short circuit fault and resume operation very quickly once the fault disappears, which improves the reliability of the system. Redundancy operation can also be realized when internal sub-module fault occurs, further improving the reliability of the system. In this paper, the characteristics of voltage and current, conduction behavior, control and fault dealing strategies, and parameters design were analyzed. The correctness and practicability of the proposed scheme were verified by the physical prototype experiment.
李建国, 赵彪, 宋强, 刘文华. 适用于中高压直流电网的开关电容接入式直流变压器[J]. 电工技术学报, 2018, 33(4): 817-825.
Li Jianguo, Zhao Biao, Song Qiang, Liu Wenhua. DC Transformer Based on Switched Capacitor in High and Medium Voltage DC Power System. Transactions of China Electrotechnical Society, 2018, 33(4): 817-825.
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2018, Vol. 33 
