Harmonic‐signature‐based islanding detection in grid‐connected distributed generation systems using Kalman filter

Abstract

Islanding in power systems is a challenge that results in various uncertainties in the system parameters, degrades power quality, and may endanger the maintenance workers. This study presents a new passive islanding detection approach for grid-connected distributed generation (DG) units. The proposed method employs a Kalman filter (KF) to extract and filter the harmonic contents of the voltage signal measured at DG terminals. A three-phase voltage signal is measured at the point of common coupling and taken as a test signal for islanding detection. First, a residual signal is generated using the KF to detect different changes in the power system. In the second step, multiple harmonic contents are estimated by the KF to calculate a criterion named selected harmonic distortion (SHD). The variation of SHD classifies between islanding and normal conditions. The IEEE 13-bus test system simulated in Matlab/Simulink is used as a testbed to assess the performance of the proposed approach. The proposed method is extensively analysed under various islanding and non-islanding scenarios. The results demonstrate that the proposed method can successfully differentiate between islanding and non-islanding events. Moreover, it provides high reliability by eliminating the non-detection zone and stands robust against the false operation.