Arc grounding overvoltage suppression strategy by using ZnO nonliear resistance grounding mode

With the development of power capacity, the arc grounding overvoltage has become increasingly prominent. Consider system capacity, the operation mode and so on, a new method to determine the current-voltage (V-I) characteristics of ZnO nonlinear resistance on the new grounding mode is put forward by analyzing the power system through symmetrical component method. Then the V-I characteristics of ZnO nonlinear resistance is obtained through the segmental linearization method. Finally, by using discrete wavelet, the multi-resolution analysis on zero sequence current is performed. According to the high frequency component energy ratio within the time window, the protection strategy based on ZnO nonlinear resistance is put forward. Results indicate that the designed ZnO nonlinear resistance parameters can suppress arc grounding overvoltage, and the proposed grounding mode is safe and reliable.