提出一种适用于带并联电抗器输电线路的三相重合闸永久性故障判别方法。该方法在故障选相基础上,以瞬时性故障π型等效模型为参考模型建立参数识别方程。对于接地故障,建立零模分量的参数识别方程;对于相间故障,建立线模分量的参数识别方程。以并联电抗器电流作为已知量,并联电抗器电感参数作为待求解参数,利用求解值与实际值的差异来区分永久性故障和瞬时性故障。瞬时性故障时,故障模型与求解模型一致,求解值与实际值差异很小;永久性故障时,故障模型与求解模型不一致,求解值与实际值差异明显。EMTP仿真结果验证了判别方法的正确性和有效性。
A novel three-phase adaptive reclosure method for transmission lines with shunt reactors was developed based on the mode component inductance parameter identification of shunt reactors to distinguish temporary faults and permanent faults. The method uses the n-type equivalent model as the prototype to build parameter identification functions. When a single phase-to-ground fault occurs, the parameter identification function of zero mode component will be built; when a phase-to-phase fault occurs, the parameter identification function of line mode component will be built. The current of the shunt reactor is given and the inductance of the shunt reactor is taken as the unknown parameter to evaluate the difference between the calculated inductance and the actual one so as to distinguish temporary faults and permanent faults. The inductance difference of the temporary fault is minute because the actual fault model is consistent with the prototype. But the inductance difference of the permanent fault is distinct because the actual fault model is inconsistent with the prototype. EMTP simulation results proved the correctness and validity of the proposed method.