Study on single-phase adaptive reclosure scheme based on parameter identification

Based on analysis of single-phase fault for transmission lines with shunt reactors, a sing-phase adaptive reclosure scheme using parameter identification principle is proposed. The scheme uses π type equivalent model of transient fault as the prototype, and takes the inductances of shunt reactor and neutral reactor as the unknown parameters, and utilizes the difference between the solved inductances and the actual ones to distinguish permanent and transient fault. In the case of transient fault, the difference is minute because the fault model is consistent with the prototype, but for the permanent fault, the difference is notable, the fault model does not coincide with the prototype. Moreover, the developed algorithm is simple and only uses one-terminal data. Theoretically, the algorithm needs shorter data-window than the phasor-based algorithms and is uninfluenced by the low-frequency swing component. ATP simulation results show that the proposed scheme can reliably and effectively distinguish permanent fault from transient fault, and apply to the single-phase adaptive reclosure in transmission lines with shunt reactors.