电力系统动态稳定性的解析延拓分析

在静态电压稳定性分析中，常把潮流极限或PV曲线的顶点视为电压稳定的临界点，由于这种分析方法未计及系统元件的动态特性，使分析结果的可信度受到影响。该文在延拓算法基础上利用小扰动分析法进行动态稳定性研究，并采用状态变量的模式参与因子进行稳定类型判别：采用带预测-校正步骤的延拓算法追踪系统的平衡解流形，延拓过程使用局部参数化方法；由获得的各平衡点出发，在计及发电 机、励磁与调速系统和SVC动态的情况下，利用小扰动分析法分析电力系统的电压稳定性，系统相关状态矩阵的形成采用对状态变量逐个施加扰动的数值计算方法。算例分析结果表明，与静态分析法得到的电压稳定极限相比，文中使用计及元件动态特性的小扰动分析法所获得的电压稳定极限具有明显的不同，而且在考虑元件动态特性的情况下，系统可以运行于PV曲线下半支的部分区域。

Power System Dynamic Voltage Stability Analysis and Stability Type Discrimination

In static voltage stability analysis, the singular point of the power flow Jacobian or the nose point of PV curve are usually considered as the critical points. As this method does not take the dynamics of the components in the power system into account, the creditability of the results obtained are more or less affected. Based on the continuation algorithm, this paper investigates the dynamic voltage stability using small signal analysis method and distinguishes the stability by modal participation factors of the state variables. Firstly, the equilibrium manifold is tracked by a locally parameterized continuation method with a prediction-correction process. Then, the dynamic stability of each equilibrium point is analyzed using the small disturbance analysis method considering the dynamics of the generators, the excitation system, the governor and the SVC. The system state matrix is calculated numerically by applying small perturbation to each state in turn. Simulation results show remarkable differences in the stability critical point between the small signal perturbation dynamic analysis and the static analysis. Also a dynamic voltage stability region is found in the lower portion of the PV curve.