False-tirp probability model for the current differential protection considering power grid operation state and communication delay

The paper studies the impact of power grid operation state and communication delay on current differential protection with a probabilistic method, and a false-trip probability model is proposed. First, the mechanism of false-trip of current differential protection is introduced and the quantitative relationship between differential current and power grid operation state and communication delay is derived. Then a false-trip probability model based on current differential protection action criterion is proposed with a probabilistic method. Simulations show the validity of the model. Based on the false-trip probability model, the key factors affecting false-trip of current differential protection are analyzed, and some useful conclusions are drawn.