Abstract: In the face of complex leakage situation of electrical equipment in hydropower station, the traditional leakage detection technology is difficult to effectively detect all abnormal situations. In view of this situation, a leakage detection technology based on differential threshold is proposed. First, the smooth filtering technology is used to filter the signal. Then the signal difference value is calculated, the time window is set up, and the initial threshold is set up according to the window, so as to detect the relative abnormal signal points. Finally, the threshold value is updated based on environmental factors, and the abnormal leakage situation is identified and warned, and the next detection cycle is carried out. The correctness and effectiveness of the technology are verified by analyzing the corresponding data, which can effectively detect the relatively abnormal residual current and prevent the leakage fire. 

Key words:

 hydropower plant, leakage current, the threshold value; fire warning