A wavelet-based passive islanding detection technique

Distribution power systems are radial in nature. Power flows in one direction from the utility to the load. Most protection, monitoring, and control devices are designed based on this unidirectional flow of power. Distributed generators (DGs) which are specifically renewable energy technologies, such as photovoltaic, wind-turbine and fuel cells are entering a stage of fast expansion. Hence, integrating DGs into the existing distribution power system will give rise to many problems such as: voltage regulation, fuse-recloser coordination, unintentional islanding, and increase the system´s fault level. Recently many islanding detection methods have been proposed. In this paper an islanding detection techniques with the help of Wavelet Transform for grid connected photovoltaic system has been presented. To verify the usefulness of the proposed method, a comparison with the conventional existing passive techniques was carried out.