输电网不对称故障电压骤降域的区间分析

Interval analysis for voltage sag areas during unsymmetrical fault in transmission network

基于区间算法提出一种预估容差输电网发生不对称故障时引起母线电压骤降的系统分析方法.通过应用对称分量法,导出容差输电网母线发生单相接地故障时的电压骤降计算矩阵以及线路发生单相接地时的母线电压骤降域计算公式,并将有向区间算法应用于电压骤降域的计算.通过检查电压骤降矩阵中的任一元素值,可以快速而且清楚地获得任意母线发生故障时,引起其它母线电压骤降程度或线路发生故障造成其他母线电压的骤降域,从而预测输电网在运行中存在的隐患和危害,便于及时进行调度和维护,提高电网的供电质量和安全运行水平.

A interval algorithm based system analysis method is proposed in the paper for predicting bus voltage sags during unsymmetrical faults in a tolerance transmission network. Firstly, the basic property of directed interval algorithm is introduced; then using symmetrical component method, the voltage sag matrix is drawn for single-phase-grounding fault at a bus, and the formula of voltage sag areas is derived for single-phase-grounding fault at a line; finally directed interval algorithm is applied to calculate the voltage sag areas. By checking any element in the voltage sag matrix, the bus voltage sags degree due to any bus fault and the voltage sag areas caused by any line fault can be obtained quickly and clearly. Potential accident and risk in power system operation can thus be predicted for dispatching and maintaining in time. It can improve power quality and safe operation level.