联于弱交流系统的VSC-HVDC稳定运行区域研究  

Study on Stable Operating Region of VSC-HVDC Connected to Weak AC Systems

作　　者：刘昇[1] 徐政[1] 

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《中国电机工程学报》2016年第1期133-144,共12页Proceedings of the CSEE

基　　金：国家863高技术基金项目(2012AA050205)~~

摘　　要：电压源换流器型直流输电(voltage source converter based high voltage direct current,VSC-HVDC)可用于联接弱交流系统,但其联于弱交流系统时的运行特性仍待深入研究。该文以VSC的交流侧稳态潮流方程为基础,归纳两种不同控制方式下VSC稳态运行时的交流侧安全稳定性约束条件,分析安全稳定判据随短路比(short-circuit ratio,SCR)的变化规律,解释VSC联于弱交流系统时无法安全稳定运行的现象,并给出求取临界短路比(critical short-circuit ratio,CSCR)的步骤流程。在此基础上,研究各种工况因素(交流等效电动势、交流等效系统阻抗、VSC运行方式等)不同时VSC的CSCR,并和PSCAD的仿真结果进行对比验证。最后,总结VSC的CSCR的主要制约因素,并给出各种运行方式下CSCR的典型范围。VSC-HVDC can be used to connect to weak AC systems. However, its operation characteristic still needs further study when it is connected to weak systems. Based on the steady-state power flow equations of the VSC AC side, this paper summarized the steady-state security and stability constraints of the VSC AC side system under two different VSC control modes, analyzed the variation law of the stability criterion with short-circuit ratios（SCRs）, explained the phenomenon that VSC cannot operate stably when it was connected to weak systems, and gave the process of acquiring the critical short-circuit ratio（CSCR）. Based on the process, the influence of different operation factors（AC equivalent system voltage, AC equivalent system impedance, VSC operation mode, etc.） on the CSCR was studied, and the results were verified by PSCAD simulation. Finally, the main constraint factors of the CSCR were concluded. And the typical CSCR ranges for different VSC operation modes were given.

关 键 词：电压源换流器型直流输电系统 弱交流系统 临界短路比 稳态运行特性 安全稳定约束条件 

分 类 号：TM72[电气工程—电力系统及自动化]