Islanding Detection of Wind Turbines Using RoCoF Measurements Based on a Symlets Wavelet transform

One of the serious concern of grid connected distributed resources is islanding problem. This condition should be prevented due to several reasons concerning such as personnel and equipment safety. This paper investigated a passive islanding detection method using wavelet transforms analysis. The proposed method is based on Rate of change of Frequency (RoCoF) measurements and processing of this signal with analysis of a Symlets wavelets transform. The presented studies are based on time-domain simulations using MATLAB, and its feasibility is evaluated with an experimental analysis in comparison with the recently reported method based on Daubechies wavelet transform. The experimental system parameters are the same as those of the simulated system. The results evaluation confirm that the proposed islanding detection method succeeds in detecting islanding mode both in the experimental and simulated systems and is superior to the Daubechies wavelet transform based detection method