基于曲线拟合的泰勒级数电网故障后电压快速准确计算

Curve Fitting and Taylor Series Based Fast Post-contingency Voltage Estimation

提出了一种基于曲线拟合的泰勒级数电网故障后电压快速准确算法.该算法可分为两阶段,第一阶段,首先通过牛顿潮流计算出故障前网络节点电压,然后利用已收敛的潮流修正方程式对线路开断参数1～3阶求导,用该导数对节点电压泰勒级数展开可得到电压函数关系曲线上线路开断参数在很小变化范围内的几个点.第二阶段,基于曲线拟合技术,利用第一阶段得到的几个点,对电压函数进行拟合,最终得出线路开断时的各节点电压.本文方法特点是在计算不同故障线路、各阶导数时共用潮流计算收敛时的雅克比矩阵,不用重新因子表分解,只需低阶泰勒展开就可得到精确的节点电压值,很好地兼顾了速度与精度.IEEE标准算例计算结果验证了本文方法的正确性与快速性.

Based on Taylor series expansion and curve fitting technique, a fast method to determine the node voltage was proposed. At the first stage, the pre-contingency voltage was calculated on the basis of Newton power flow approach, and the 1 to 3 order derivatives of voltage with respect to branch outage parameter were calculated by using the convergent power flow equation of the base network topology. Several points around the fault branch parameter could be obtained by using Taylor series expansion. At the second stage, the function of the node voltage with respect to the fault branch parameter was obtained by using curve fitting technique. The related parameters in the node voltage function were determined with four voltage equations. The advantage of the proposed method is that the coefficient matrix of various derivatives of node voltage with respect to the fault branch parameter is identical, and there is no need for the re --factorization of the coefficient matrix. The standard IEEE system analysis results have verified the correctness and fastness of the proposed method.