基于级联全桥型直流断路器的直流配电网自适应重合闸方案

柔性直流配电网是配电系统的重要发展方向，可以采用电缆和架空线2种方式组网。鉴于架空线路瞬时性故障多发的特点，基于架空线的柔性直流配电网应配备有效的自适应重合闸方案，以提高供电可靠性。为实现这一目标，从断路器线路端电压与电流的相位差异特征出发，提出一种基于级联全桥型直流断路器控制的自适应重合闸方案。首先,通过断路器转移支路的主动控制产生一定频率的故障检测电压；进而，根据断路器线路端电压电流在对应频率下相位特征的差异，区分瞬时性和永久性故障，并进一步分析了过渡电阻等因素的影响；最后，利用PSCAD/EMTDC仿真平台搭建了柔性直流配电网模型，验证了所提自适应重合闸方案的可行性和有效性。

Adaptive Reclosing Scheme for DC Distribution Network Based on Cascaded Full-bridge DC Circuit Breaker

Flexible DC distribution network is an important development area of power distribution system, which can be built with overhead lines or cables. Considering the faults on overhead lines are mostly temporary, it is necessary for DC distribution network based on overhead lines to adopt effective reclosing scheme to improve power reliability. In order to realize this objective, this paper utilizes the different phase characteristics between voltage and current of the breaker on the line terminal, and further proposes an adaptive reclosing scheme based on the cascaded full-bridge DC circuit breaker (DCCB). Firstly, the fault detection voltage at a given frequency is generated by the active control of the transmission branch of the DCCB. Secondly, temporary or permanent faults are distinguished according to the different phase characteristics of voltage and current on the line terminal of the DCCB at this frequency. Moreover, the influence of some factors like transition resistance is analyzed. Finally, a model of DC distribution network is built on PSCAD/EMTDC to verify the feasibility and effectiveness of the proposed adaptive reclosing scheme.