Abstract:
The existing flexible suppression methods of ground faults in distribution networks are greatly affected by the factors like the measurement accuracy of ground parameters, the load changes, the ground fault resistance and the line impedance voltage drop. Therefore, a novel fusion suppression for ground faults in distribution networks that adapts to the parameter and load changes is proposed in this paper. Based on the analysis of the ground fault current distribution law, a fault current suppression method based on the fault phase current regulation is put forward. The fault point current is suppressed by regulating the fault phase current to equal the fault phase load current. A real-time extraction for the load current is raised to adapt to the load changes without the measurement of the ground parameters. In addition, a parallel current-voltage double closed-loop control method is presented according to the application scope of the principles of current and voltage suppression. Both the fault current and voltage are suppressed to accommodate the effects of the ground fault resistance and line impedance voltage drop. Simulation and experimental results prove the effectiveness and advantages of the proposed method.