考虑负荷动态模型的暂态电压稳定快速判断方法  

Method for Transient Voltage Stability Quick Judgment Considering Load Dynamic Model

作　　者：林舜江[1] 李欣然[1] 刘杨华[1] 李培强[1] 罗安[1] 刘光晔[1] 

机构地区：[1]湖南大学电气与信息工程学院,湖南省长沙市410082

出　　处：《中国电机工程学报》2009年第4期14-20,共7页Proceedings of the CSEE

基　　金：高等学校博士学科点专项科研基金(20070532052)

摘　　要：提出一种负荷采用三阶感应电动机并联恒阻抗动态模型时系统暂态电压稳定快速判断的方法。针对采用牛顿法求取故障后系统主导不稳定平衡点(controlling unstable equilibrium point,CUEP)存在的初值选取难题,提出一种实用但不失严谨的解决方案:通过识别给定故障的主导负荷母线,对主导负荷母线以外系统由故障后稳定平衡点处的状态进行戴维南等值,对负荷中感应电动机部分采用其稳态等值电路,再由感应电动机的转矩特性求得CUEP附近的一个点作为近似的CUEP,以此为迭代初值可靠求得CUEP;采用二阶正规型来近似CUEP的稳定流形的方法求得近似的局部吸引域边界;由仿真得到故障清除时刻系统的状态并根据该状态是否位于吸引域内判断系统的暂态电压稳定性。文中推导出了该方法的系统数学模型的一般化描述,并通过对一个5节点系统和IEEE-9节点系统的计算结果验证了该方法的正确有效和良好精度。A method which can quickly determine the transient voltage stability of power system considering the third order induction motor paralleled with const impedance dynamic load model was presented. Aimed at the problem of choosing the initial value when the Newton method is used to compute the controlling unstable equilibrium point （CUEP）, a practical and rigorous solving scheme was presented： by identifying the controlling load bus of the given fault, and using the Thevenin equivalent circuit to represent the rest of the system at the state of the post disturbance stable equilibrium point, using the steady equivalent circuit to represent the induction motor in composite load, and then using the torque characteristics of induction motor, a point near the CUEP is gained to be the initial value. The second order normal forms was used to approximate the stable manifold of CUEP, and the local approximating boundary of the region of attraction of the post disturbance stable equilibrium point was gained. Then just by simulating the state of the system at the fault clearing time, the transient voltage stability of the system could be determined. The common representation of the mathematics model of the system of this method was also deduced. For the instances of a 5 buses system and the IEEE-9 buses system, the correctness and precision of the method was validated.

关 键 词：电力系统 暂态电压稳定 感应电动机 主导不稳定平衡点 吸引域 

分 类 号：TM712[电气工程—电力系统及自动化]