A new method of fault line selection and phase selection based on zero sequence voltage regulation

In order to solve the problem of low accuracy of line selection and phase selection when a high resistance grounding fault occurs in a distribution network system, a new method of line selection and phase selection for a grounding fault based on zero-sequence voltage regulation is proposed. By analyzing the phase characteristics of the zero-sequence current of each feeder before and after the zero-sequence voltage regulation, the fault line can be selected according to the obviously different absolute value of zero sequence current phase difference between the healthy line and the fault line. On the basis of completing the fault feeder identification, the phase values of fault phase selection function are calculated using the zero-sequence current of the fault line before and after zero-sequence voltage regulation, and finally the phase corresponding to the smallest fault phase selection function value is the fault phase. The simulation analysis shows that the proposed method not only effectively combines line selection with the phase selection method, but it is also suitable for low and high resistance grounding faults operated in different ways through a flexible adjustment coefficient. © 2020, Power System Protection and Control Press. All right reserved.