考虑线路电阻情况下的失步振荡中心定位研究

Study on out-of-step oscillation center position considering line resistance

电力系统失步情况下,失步振荡中心的定位准确与否会影响解列措施的实施。准确定位失步振荡中心对电网的稳定运行具有重要意义。针对实际电网中输电线路并非纯感性元件,而是包含电阻特性的情况,指出电力系统在线路电阻与电抗成固定关系情况下,会存在两个失步振荡中心点,进而影响失步解列装置的正确动作,引发电网不同区域之间的失步振荡事件,严重影响电力系统的安全稳定运行。分别通过向量分析方法、电网特性理论推导两种方法对多振荡中心情况进行了相互印证,并进一步给出振荡中心位置和幅值受功角差及线路阻抗角影响的结论。基于单机无穷大系统,对分析所得结论进行了仿真分析,仿真分析结果验证了本文研究内容的正确性。

When the power system is out of step,the positioning of the out-of-step oscillation center will affect the implementation of the delisting measures. Accurately locating the out-of-step oscillation center has an important significance for the stability of the entire network of the power grid. In view of the fact that the transmission line in the actual power grid is not only a purely inductive component,but also contains resistance characteristic,hence this paper points out that there exists two out-of-step oscillation centers in the case that the out-of-step system has a fixed relationship between the circuit resistance and the reactance,which affects the correct action of the out-of-step disengagement device and causes adverse grid events eventually. Through the vector analysis method and theory derivation,the situation of multiple oscillation centers is verified mutually. The oscillation center position and amplitude are affected by the power angle difference and the line impedance angle. Through the simulation analysis of the single-machine infinity system,the correctness of the analysis conclusion is verified.