电力系统大扰动下暂态电压稳定的动态特征分析

摘要

A dynamic eigen analysis method is presented aiming at the defects that current voltage stability research results cannot give the explicit criterion about transient voltage stability information. First, this paper establishes an integrated mathematical model reflecting power system transient process with the consideration of speed-adjusting and excitation-control, i.e., Non-linear Differential Algebraic Equations (NDAE). Second, all the eigen values and left, right eigen vectors are solved by using implicit trapezoidal integration method to build Jacobian matrix dynamically in the process of step-by-step integration of NDAE. Finally, this paper calculates all the participating factors of eigen vectors corresponding with all status variables. Then, transient voltage instability criterion is proposed. Simulation results after comparing the method with time domain simulation demonstrate that the transient voltage instability criterion is correct. The paper provides a novel way to research power system transient voltage stability in terms of combining linear system theory with numerical integration.This work is supported by Natural Science Foundation of Liaoning Province (No. 20092148).%针对目前电力系统电压稳定性研究成果难以给出明确的暂态稳定判定信息的缺陷,提出一种电力系统大扰动下暂态电压稳定的动态特征分析方法.该方法首先建立反映电力系统暂态过渡过程的计及调速与励磁控制的综合数学模型,即非线性微分代数方程组(Non-linear Differential Algebraic Equations,NDAE);其次在运用隐式梯形积分法对NDAE进行逐步积分过程中动态生成Jacobian矩阵,并求解出全部特征根及左,右特征向量;最后计算出各个状态变量与之对应特征向量的相关因子,基于此给出暂态电压失稳的判据.该方法通过与时域仿真法的对比结果证明所提出系统暂态电压失稳判据的正确性,为今后从线性系统理论与数值积分结合的角度来研究电力系统暂态电压稳定性提供一个新的思路.