基于最小相位差全局搜索的高压输电线路故障测距

Fault location based on global search of minimum phase difference for high voltage transmission lines

提出了一种针对两相接地故障的单端故障测距算法。利用保护安装处的电压、电流,估算线路上的残压和故障支路的故障电流,通过故障点残压与故障分量电流相位差最小的特征进行定位。为了精确地考虑分布电容的影响,采用贝瑞隆模型计算全线的电压分布。通过相模变换,建立了基于模空间的输电线路方程,设定故障点后,通过相模反变换还原出预设故障点的相电压残压。为了克服超越方程求解的困难,提出采用全局一维搜索的方法,对全线路的电压、电流分布进行估算,找出其中相位差最小的电压与电流,其对应的距离即为故障距离。大量的EMTDC仿真试验表明,不同过渡电阻、不同故障点和不同故障合闸角的情况下,该算法均能够准确测量故障距离,最大测距误差均在0.5%以内。

A single-end fault location method is proposed for dual-phase grounding fault,which estimates the residual voltage of lines and the current of faulty branch according to the voltages and currents from protections and locates the fault according to the minimum phase angle difference between the residual voltage and fault component current.With the consideration of distributed capacitance,Bergeron model is applied to calculate the voltage distribution over whole line.The equation of transmission line is established based on the modulus space by phase-modulus conversion and the one-dimensional global search is proposed to estimate the distribution of voltage and current over whole line.Results of EMTDC simulation show that,the proposed algorithm locates the fault accurately for different transition resistances,different fault locations and different fault angles,and the maximum error is within 0.5 %.