参数不对称同塔四回输电线的零序四分量法及故障分析

同塔四回输电线路大量存在阻抗参数的不对称性。为了完全解耦参数不对称的阻抗矩阵，提高同塔四回输电线路的故障分析精度，需引入新型的相模变换方法。为此，参考已有相模变换的解耦思路，提出零序四分量法。该方法保持各回线的正、负序量不变，仅在零序中单独引入一个同向量和三个带修正系数的环流量，从而完成矩阵的完全解耦。零序四分量法可分别应用于同电压等级和跨电压等级的参数不对称同塔四回线系统的故障分析。由序分量定义与故障边界条件可得各故障复合序网。仿真结果证明了零序四分量法所得故障分析结果的正确性。

Four zero-sequence component method of asymmetry-parameter four-parallel lines on the same tower and its fault analysis

Many four-parallel lines on the same tower show the asymmetry of parameters. A new phase-mode transform introduced is introduced to totally decouple the asymmetric matrix and improve the accuracy of fault analysis of four-parallel lines. Referring decoupling method of existing phase-mode transformation, four zero-sequence component method (FZCM) is proposed. Keeping positive and negative sequence components unchanged, this method introduces a same-direction component and three circulation components with correction factors to decouple the matrix. FZCM can be applied to fault analysis of asymmetry-parameter four-parallel lines under same voltage grade or different voltage grades. Fault sequence network can be figured out by the sequence component definition and fault boundary condition. Simulation results prove the validity of four zero-sequence component method for fault analysis.