A Reclosing Scheme of Hybrid DC Circuit Breaker for MMC-HVdc Systems
A Reclosing Scheme of Hybrid DC Circuit Breaker for MMC-HVdc Systems
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DOI：
10.1109/jestpe.2020.3025598
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发表时间：
2021-12
影响因子：
5.5
通讯作者：
Shuo Zhang;G. Zou;Chunhua Xu;Weijie Sun
中科院分区：
文献类型：
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作者：
Shuo Zhang;G. Zou;Chunhua Xu;Weijie Sun
随着大容量、长距离输电的需求不断增加，需要使用架空线路，这大大增加了临时故障的概率。在故障线路被混合直流断路器（HCB）隔离后，在发生暂时故障时，通过重合闸可以立即恢复供电。然而，当发生永久性故障时，易碎的半导体开关将在HCB重合闸后经历两次连续故障。因此，本文提出了一种以瞬时性故障和永久性故障的识别为核心的重合闸方案，以避免HCB的非选择性重合闸。通过控制HCB中的半导体开关，行波信号被注入到直流线路中。然后，可以通过注入信号的传播特性的差异来确定线路上是否存在故障。在PSCAD/EMTDC平台上搭建的基于模块化多电平换流器的点对点和四端高压直流试验系统验证了该重合闸方案的有效性。大量仿真表明，它对故障电阻等具有鲁棒性，并且没有识别盲区。此外，即使发生永久性故障，对系统健康部分的影响也很小。
With the increasing demand for large capacity power transmission over long distance, the use of overhead lines is required, which greatly increases the probability of temporary faults. After the faulty line is isolated by hybrid dc circuit breakers (HCBs), the power supply can be restored immediately by reclosing them in the event of temporary fault. However, fragile semiconductor switches will undergo two consecutive faults after the reclose of HCBs when permanent fault occurs. Therefore, a reclosing scheme is proposed in this article to avoid the nonselective reclose of HCBs, whose core principle is an identification method of the instantaneous and the permanent faults. By controlling semiconductor switches in HCB, traveling wave signal is injected into the dc line. Then, whether the fault exists on the line can be determined by the difference in propagation characteristics of the injected signal. The effectiveness of the proposed reclosing scheme is verified by both point-to-point and four-terminal high-voltage dc (HVdc) test systems based on modular multilevel converter built in PSCAD/EMTDC platform. Extensive simulations show that it is robust to fault resistance, etc., and has no identification dead zone. Besides, it has little impact on the healthy part of the system even the permanent fault occurs.