A Novel Criterion for Neutral Current Differential Protection

A novel criterion for neutral current differential protection is presented in this paper, which is based on a full research into exist neutral current differential protection schemes used in transmission lines. Compared to traditional ones, the novel criterion can improve the sensitivity under internal fault conditions and improve reliability under external fault conditions. More importantly, the novel criterion overcomes the deficiency of sensitivity of traditional criteria under single-pole open condition and possesses more satisfactory performance. The applicable range of the novel criterion is given by theoretic analysis and simulation results are presented to verify the applicability and effectiveness of the proposed criterion