西北750kV电网动态稳定特性分析和控制策略

Analysis of Dynamic Stability Characteristics of 750kV Northwest China Power Grid and Research on Its Control Strategy

分析了西北电网在2008年750kV骨干网架初步形成后西电东送方式下的动态稳定特性,并与目前西北电网的状况进行了比较。基于时域仿真法和小干扰稳定分析,以及Prony分析和留数法提出了西北750kV电网PSS配置及其参数优化整定方案。用中国电科院电力系统综合分析程序对750kV系统的稳定性进行了仿真计算,结果表明750kV骨干网架将提高西北电网的动态稳定性,但由于750kV网架还比较薄弱,当陕甘断面上的750kV联络线退出运行时,存在阻尼不足问题,可能诱发低频振荡,需要在电网中装设PSS以保证系统的安全稳定运行。结果表明了所提方案的有效性。

The main 750kV power network of Northwest China Power Grid will be built up preliminarily in the year of 2008, the dynamic stability of Northwest China Power Grid under the operating mode of transmitting power from West China to East China at that time is analyzed and compared with present situation of Northwest China Power Grid. Simulation results show that after the building up of 750kV main power network the dynamic stability of Northwest China Power Grid will be improved. Due to the relative weakness of the 750kV main power network, the insufficient damping caused by the outage of 750kV tie-line, which connects Shaanxi power network with Gansu power network, may lead to low frequency oscillation, so that it will be necessary to configure PSS to ensure stable and secure operation of Northwest China Power Grid. Based on the results from time-domain simulation, small signal stability analysis, Prony analysis and residual method, the configuration of PSS in the 750kV power network of Northwest China Power Grid and corresponding optimal parameter setting scheme are proposed. Calculation results show that the proposed scheme is valid.