基于黄金分割搜索的电压暂降域快速识别方法

A Fast Identification Method of Voltage Sag Domain Based on Golden Section Search

针对大型复杂电网中敏感负荷的电压暂降域难以准确识别的问题,提出一种基于黄金分割搜索的电压暂降域快速识别方法。首先,求得网络中发生各类短路故障时敏感负荷节点的电压暂降幅值解析式,并引入节点判定向量和线路关联向量,以及相应的判定准则,实现对所有线路临界点的快速分类计算;接着详细阐述了传统插值法存在的问题,并提出一种由黄金分割搜索改进的插值法,以期为正割迭代提供更优的初值点,提高临界点计算的准确度;因考虑到拟合的二次曲线难免存在偏差,故使用故障点法作为补充算法,用以计算有求解困难的线路;最后,以IEEE30节点标准测试系统为例,验证了该方法能在保证计算精度的前提下,简化电压暂降域的求解过程,提高算法的收敛速度,并广泛适用于大型复杂电网。

In view of the difficulty in accurately identifying the voltage sag domain of sensitive loads in large and complex power grids,a fast voltage sag domain identification method has thus been adopted based on golden section search.Firstly,an analytical formula can be obtained for the voltage temporary drop amplitude of sensitive load nodes in the network when various types of short circuit faults occur,with the node judgment vector,line correlation vector and corresponding judgment criteria to be introduced to realize a fast classification calculation of all line critical points.Then,a detailed elaboration has been made of the traditional interpolation methods,with an improved interpolation method proposed on the basis of golden section search,which helps to provide better initial values for secant iteration,thus improving the accuracy of critical point calculation.In view of the inevitable deviation of the fitted quadratic curves,the fault point method is adopted as a supplementary algorithm to calculate routes that are difficult to solve.Finally,taking the IEEE30-node standard testing system as an example,it is verified that the proposed method can simplify the solution process of voltage sag domain,and improve the convergence speed of the algorithm on the premise of ensuring calculation accuracy,which makes it widely applicable to large and complex power grids.