应用模态级数3阶解析解分析大干扰低频振荡机理

在动态电力系统3阶解析解的基础上,分析了遭受大干扰的电力系统所表现出来的复杂的非线性动态特性.提出由于3阶解析解中非线性高阶项被大干扰激发,使系统模态间的高阶非线性相关作用加剧,才导致了系统出现增幅低频振荡这一新观点,从理论上有效地解释了大干扰下增幅低频振荡出现的原因.对一个电力系统算例的分析验证了上述观点的正确性,也证明了3阶解析解与2阶解析解相比在分析大干扰下系统动态特性的有效性.

Mechanism Analysis of Increasing Amplitude Low Frequency Oscillation Based on Modal Series with Third-order Analytical Solution

The third-order analytical solution of dynamic power system is used to investigate the complex nonlinear dynamical behavior of power systems after the occurrence of large disturbances.A new point of view is presented firstly to theoretically explain the reason of the increasing amplitude inertia mode oscillations after occurring large disturbances,that the higher order terms in the third-order analytical solutions are exited by the large disturbance and the nonlinear interaction among the modes is intensified.The analysis result for a power system case shows that the new finding is correct and the third-order analytical solution is more effective in analyzing the complex dynamical behavior of power systems after occurring large disturbances than the second-order analytical solution.