A novel islanding detection method of distributed generator based on wavelet transform

With the increased use of distributed generators (DGs), the composition of power systems has been changed. The ability to maintain a secure supply with high power quality is becoming more challenging. In this paper, wavelet transform is first used to analyzing of grid-connected voltage. Wavelet denoising and the detection of the non-stationary signals are attained. Islanding can be detected through the analysis of the non-stationary signals. There is no need to inject disturbances, and no interference to the grid, and has the potential to enhance the performance of DGs. Simulation results demonstrates the effectiveness of this technique.