可控串联电容补偿器的负阻尼特性研究

STUDY ON NEGATIVE DAMPING CHARACTERISTIC OF TCSC

由于在暂稳控制器的设计中通常将可控串联电容补偿器 (TCSC)处理为带限幅器的一阶惯性环节 ,而忽略了电力系统动态行为对 TCSC脉冲触发过程影响以及装置动态响应特性的研究。文中建立了装有 TCSC的电力系统的扩展 Phillips- Heffron模型 ,通过分析 TCSC对系统同步和阻尼转矩的贡献 ,给出了在开环定触发角控制下 TCSC表现为负阻尼特性的解析解。基于NETOMAC的数字仿真结果验证了模型分析的正确性 ,同时指出通过合适的底层控制策略可以减弱和消除负阻尼 ,有效地改善 TCSC的动态响应特性。

The impact of power system dynamics on thyristor pulse firing control and dynamic response characteristic of thyristor controlled series compensator (TCSC) has always been omitted because TCSC is usually handled as a first-order lag element used for the design of transient stability controller. In this paper, an extended Phillips-Heffron model of a power system with TCSC is established. The analytical solution that TCSC damping characteristic appears negative under open-loop control with constant firing angle is obtained by analyzing the dedication of TCSC to synchronous and damping torque in power system. The NETOMAC digital simulation results verify the correctness of model analysis, and show that the negative damping characteristic can be decreased and eliminated by certain suitable bottom-level control strategies, which can improve the dynamic response characteristic effectively.