An optimal/adaptive reclosing technique for transient stability enhancement under single pole tripping

This paper presents an integrated autoreclosure scheme (IAS) for transmission networks. The IAS operation is based on merging the functional advantages of the adaptive reclosing technique (ART) and the optimal reclosing technique (ORT). The ART identifies the nature of the fault, transient or a permanent fault, and determines the fault persistence time of a transient fault by analyzing the harmonic of the fault phase voltage using wavelet packet transform (WPT). The ORT is dependent on the load angle of the generators that minimizes the systems oscillation. The resulted information from the adaptive reclosing and the optimal reclosure timing units can effectively settled to achieve the optimum reclosing strategy that able to enhance power system stability. The proposed IAS is merited by an adaptive threshold level while needed information are captured from single end only. The IAS performance assessment compared to conventional reclosing schemes is carried out by using proposed voltage and speed indices. Examination of the proposed IAS is successfully achieved at different fault scenarios that involve various fault locations, inception angles, and representation of secondary arc characteristics. Added to that, the capability of the proposed scheme is confirmed considering the effects of shunt compensators, reactors and capacitors. Numerous simulation studies are emulated using MATLAB/SIMULINK on two test systems with different configurations. Simulation results indicate that the proposed reclosing method can enhance the transient stability.