简单电力系统暂态电压稳定的直接分析法

对综合负荷采用三阶感应电动机并联恒阻抗动态模型,构建了简单电力系统暂态电压稳定分析的微分代数方程组(DAE)模型,并采用非线性动力系统理论计算系统故障后稳定平衡点的吸引域。针对采用牛顿法求取系统不稳定平衡点碰到的初值选取问题,通过对综合负荷感应电动机部分采用其稳态等值电路来求得不稳定平衡点;并采用将非线性系统化为规范型线性系统的方法求得系统故障后稳定平衡点的吸引域边界;进而只须仿真得到故障切除时刻系统的状态即可判断系统能否保持电压稳定。通过与系统全故障过程仿真结果的比较验证了本文方法的正确性。

The Direct Analysis Method for Transient Voltage Stability of Simple Power System

The third-order induction motor paralleled with const impedance dynamic model is used to represent composite load, and the differential and algebraic equations (DAE) model of transient voltage stability analysis of a simple power system is established. By nonlinear dynamic system theory, the region of attraction of the post disturbance stable equilibrium point of the system is computed. In terms of the problem of determining the initial value when Newton method is used to compute the unstable equilibrium point, the method which uses steady model to represent the induction motor part of composite load is introduced. By converting nonlinear system to normal form linear system, the boundary of the attraction region of the post disturbance stable equilibrium point is computed. Then the transient voltage stability of the system can be determined just by simulating the state of the system at the fault clearing time. Compared to the simulation results of the whole fault of the system, the correctness of the method is verified.