Fault line selection method based on steady-state zero-sequence voltage

Traditional grounding line selection devices is easily affected by factors like unbalanced current and difference of current transformers, leading to inaccurate result. To solve this problem, a new method based on zero-sequence voltage is proposed. In this paper, unified model of zero-sequence voltage for healthy and fault lines were obtained, and then distribution characteristics of zero-sequence voltage were obtained. Because the distribution characteristics of zero-sequence voltage between healthy and fault lines are different, voting mechanism and matrix describing the same characteristics of healthy lines and the difference between fault and healthy lines were used to reduce impact on selection. PSCAD simulation results show that the method is effective.