Fault Location Algorithms for Parallel Transmission Lines Using Two Terminals Nonsynchronized Current Data Suonan Jiale
Song Guobing Xu Qingqiang Wang Shugang (Xi抋n JiaoTong University Xi抋n 710049 China)
A novel time-domain algorithm of fault location for parallel transmission lines on the same tower is presented in this paper. Considering that the parallel transmission lines can be decomposed into Common Component Net and Differential Component Net, the voltage distributions along Differential Component Net can be calculated with two-terminal current samples only. The new algorithm is based on the fact that the difference between voltage distributions, calculated with two terminal synchronized currents, is smallest at fault point. The synchronization is achieved by searching the minimum of the fault locating criterion. No voltage-sample is used, so the proposed algorithm is independent of the weak transferring ability of CVT. The algorithm needs a short data-window, which is just a little longer than double propagation time of parallel transmission lines. From transient to steady state, any segment of fault data can be used to locate faults. The distributed parameter transmission line model is used to improve locating accuracy, and simulations show that the locating errors are less than 150 meters. Additionally, the fault types and fault resistance have no influence on the precision.