Study of Island Detection Based on Wavelet Network

Island detection is a necessary safety protection in distributed generation system, which can be classified into two categories, one is active island detection, the other is passive island detection. Both of them have shortages. Passive island detection has long detection time and large blind zone, active island detection can usually pollute power quality. This paper combines island detection with wavelet network,takes the measure of time-frequency entropy to analyze transient signal, use wavelet network to identify signal type, and determine whether the island detection starts. This paper makes 4 models on Matlab, which are islanding model, load step changing model, single-phase grounding fault model, and lightning interference model. Then analyzes data in Matlab. This paper verifies effectiveness and practicability of wavelet network in island detection.