可控串联补偿电容器控制角模型及其在静态电压稳定研究中的应用

提出一个可控串联补偿电容器(TCSC)静态模型，将TCSC基频等值电抗表达为其控制角的显函数并考虑了其自身的功率损耗。将控制角作为状态变量处理，推导了4种典型控制模式下的TCSC牛顿潮流方程并在连续潮流算法中予以实现，并指出恒功率控制、恒电流控制和恒相角差控制中所需的控制参考量由系统基本工况下指定线路补偿度的恒阻抗控制获得。用IEEE30母线系统进行仿真计算，结果表明该模型具有较高的求解效率及数值稳定性，通过控制角可以方便地获取线路的补偿度。用该模型进行电压稳定分析表明，选择最优的安装位置及合适的控制模式是提高电压稳定性的关键因素。恒阻抗控制对提高电压稳定性的效果是最好的，而不适当的控制模式以及不适当的安装位置则可能导致系统的电压稳定裕度降低。

TCSC CONTROL ANGLE MODEL AND ITS APPLICATION IN STATIC VOLTAGE STABILITY RESEARCH

This paper presents a static model of thyristor controlled series capacitors (TCSC). Base frequency equivalent reactance of TCSC is expressed as an explicit function of its control angle and power losses of TCSC are also considered. Treating control angle as the state variable, Newton power flow equations with respect to four typical control modes of TCSC are derived. This model is incorporated into continuation power flow and is tested in IEEE 30-bus system. It must be pointed out that the control reference values used for constant power control, constant current control, and constant transmission angle control are determined by constant reactance control at base loading and specified line compensation level. The results show high efficiency and good robustness of Newton power flow algorithm including TCSC model, and compensation level of line can be easily acquired by control angle. The effect of TCSC on voltage stability of system is evaluated, and the results show that optimal location and proper control mode of TCSC are the key issues to enhance voltage stability of system. In addition, constant reactance control provides the most enhancement on voltage stability margin, whereas inappropriate location or control mode may reduce the margin.