An implementation of improved combine active islanding detection method based on frequency and phase perturbations

Nowadays, the fossil energy is rapidly reduced by consumption of human. Hence, many countries have been very interested in renewable energy that would substitute the fossil energy in the future. The renewable energy is normally utilized with the grid connected system. The harmful phenomenon that occurs with the grid connected system is the islanding operation. One of the active islanding detection methods is based on both frequency and phase perturbations by using the active frequency drift (AFD) and slip mode frequency shift (SMS), respectively. However, the chopping fraction (cf) is only a fixed value. In this paper, an improved combine active islanding detection method is proposed to eliminate the fixed cf problem in the conventional combine active method by utilizing Sandia frequency shift (SFS) instead of AFD method. The performance of the proposed active method is evaluated by employing the Matlab/Simulink simulations and experiments. According to the results, the NDZ and detection time of the proposed active method are better than the conventional combine active method.