Abstract:
After a single-phase grounding fault occurs in the mine high-voltage power network, it is important to identify the fault section quickly for the safe and stable operation of the mine power network. The existing research on fault section location in distribution networks rarely involves mine high-voltage power network, while the traditional steady-state method has a dead zone when it is used for neutral point grounding system via arc suppression coil. And the transient method needs to be used with phase selection device and has the disadvantage that the fault characteristic quantity decays with time. By analyzing the characteristics of the one-mode component of the current obtained by Clark transform under the single-phase grounding fault additional state of the mine high-voltage power network, it is concluded that the one-mode component of the current upstream of the fault point is significantly larger than that downstream of the fault point, and the one-mode component of the current is not affected by the fault phase and the arc suppression coil current. A location method of the fault section of the mine high-voltage power network based on the one-mode component without phase selection is proposed. The method uses Clark transform to obtain the current one-mode components of each monitoring point in the fault additional state of the mine high-voltage power network, and calculates the current one-mode component amplitude difference on both sides of each section. The fault path is determined according to the minimum current one-mode component amplitude difference at the fault path branch node, and then the fault section is determined according to the maximum current one-mode component amplitude difference on both sides of the fault section at the fault path. Simulation and experimental results show that the method can achieve accurate fault location when a single-phase grounding fault occurs in any phase of the mine high-voltage power network, and is not affected by the initial fault angle, fault grounding resistance, fault location and system running mode.