Passive Islanding Detection Method Using Wavelet Transform

Islanding detection methods are classified into two different categories: local and remote based methods. Local method is divided into three methods: Active, Passive and Hybrid. In this paper, voltage measurement as a passive method in islanding detection using Wavelet Transform (WT) is discussed. The voltage using WT changes in the voltage signal and the suitable threshold value for correct detection is determined. For determination of the threshold value, the voltage at specified interval times and buses are sampled, then the measured values are converted to voltage signal and analyzed with WT toolbox in MATLAB software. The induction motor and a distribution network with linear and nonlinear loads are simulated and studied in several cases. The network is simulated in PSCAD/EMTDC software. Islanding detection in the presence of Synchronous Generator (SG) as a DG, the nonlinear loads and capacitor bank, switching at different buses of the network are considered.

Keywords:

Distributed Generation (DG) , Islanding Detection , Threshold value , Wavelet Transforms (WT)