中文摘要：

为了研究静止同步补偿器（STATCOM）对高压直流（HVDC）输电系统稳定性的改善作用,分析了不同容量的STATCOM对HVDC输电系统运行极限的影响。在PSCAD/EMTDC中搭建了含有STATCOM的HVDC输电模型,分别分析了在逆变侧交流母线发生故障和连接较弱受端系统情况下,STATCOM对单馈入HVDC输电系统的影响。此外,搭建了含有STATCOM的双馈入HVDC输电系统,研究了STATCOM对多馈入HVDC输电系统运行极限的影响,以及直流子系统之间的电气距离对STATCOM改善作用的影响。仿真结果表明：接入STATCOM可以使HVDC输电系统在较低的短路比情况下稳定运行;随着STATCOM容量的增大,系统临界短路比的降幅逐渐减小;在多馈入直流系统中,随着子系统之间电气距离的增大,STATCOM对远端子系统临界短路比的改善作用降低。

英文摘要：

In order to investigate the effect of STATCOM on stability of HVDC power transmission system, we analyzed the influences of STATCOM with different capacities on operation limits of HVDC power transmission system. We de- veloped a simulation model of HVDC power transmission system with STATCOM in PSCAD/EMTDC, and investigated the operation performances of HVDC power transmission system in the presence or absence of STATCOM under AC system fault at inverter side and weak receiving system scenarios. Moreover, we built a dual-infeed HVDC power trans- mission system in the presence of STATCOM. Then we researched the effect of STATCOM with different capacities on operation limits of dual-infeed HVDC system, and the impact of electrical distance among DC subsystems on STATCOM. The simulation results show that introducing STATCOM guarantee that the HVDC system can run steadily at a small short circuit ratio. The decline amount of short circuit ratio will reduce with the increase of STATCOM capacity. In mul- ti-infeed HVDC system, the improvement effect of STATCOM on short circuit ratio for the remote subsystem will reduce with the increase of distance among HVDC subsystems.