TCSC在次同步谐振中的借阻尼现象

Borrow damping phenomena of TCSC to subsynchronous resonance

采用了基于时域仿真的复转矩系数法研究电力系统的电气阻尼特性。在IEEE次同步谐振第一标准模型的基础上,分别将其25%,50%,100%容量的固定串补替换为TCSC后进行仿真分析。分析结果表明,在串补度相同的情况下,系统总阻尼近似守恒,TCSC基本不提供正阻尼,但TCSC由于其高度非线性,使系统不同频率间发生了能量交互,从而增加了某些频率的阻尼,同时也降低了另外一些频率处的阻尼,出现了借阻尼现象。讨论了借阻尼现象对SSR的正反两方面影响,并利用仿真实验验证了TCSC抑制和引起SSR的可能性。该现象的发现对TCSC的实际运行具有一定的参考价值。

The complex torque approach realized by frequency time domain simulation is adopted to study the electrical damping characteristics. The study is based on the IEEE first benchmark model. The subsynchronous resonance（SSR） damping characteristics of the model is studied in three cases of changing 25%, 50%, and 100% of the fixed series capacitor to thyristor-controlled series capacitor（TCSC）. The results show that the total damping of the system is conserved under the condition of the same compensation degree, and TCSC can not provide damping for the system. But TCSC causes energy interactions between different frequencies because of its nonlinear behavior. The results also show that TCSC increases electrical damping of some frequencies while reduces electrical damping of others, that is the borrow damping phenomena. Finally, this paper discusses the negative and positive impact of the borrow damping phenomena on SSR, and uses time domain simulation to verify the possiblity of mitigating and stimulating SSR. The finding of this phenomena offers a useful reference for the actual operation of TCSC.