A novel phase selection method based on instantaneous reactive power

Travelling wave protection, which performs brilliantly with high operation speed, is perfectly feasible for ultra-high voltage (UHV) transmission line protection. Since nearly 70% faults in UHV transmission lines are single-line to ground (SLG) faults, the cooperation of single phase tripping and auto-reclosing is the most common and effective method to isolate SLG faults and improve the stability of the power system. Among the techniques of single phase tripping, phase selection is an essential part for its contribution to select the exact faulted phase. However, traditional phase selection algorithms do not work well with traveling wave protection due to their low recognition speed. In this regard, an innovative phase selection method is presented in this paper. Firstly, reactive energies are proved to have significant differences for healthy and faulted phase respectively. On this basics, instantaneous reactive power is adopted to construct selection criterion to accelerate identification speed. Various simulation results have been conducted to validate that the proposed method is advantageous for travelling wave protection with rapid and accurate identification.