An Multiple DG Islanding Detection Method Base on The DWT in Unbalance Distribution networks

According to the IEEE standards 1547-2003 Islanding concept is a condition in which a portion of the utility system that contains both loads and Distributed Generation (DG) remains energized while isolated from the remainder of the utility system and in this condition DG must be disconnected at most within 2 seconds. Propose of this paper is, fast and accurate method for Distributed generation islanding detection in the unbalance distribution networks in presence of Multi DG (MDG) based on analysis of DG transient terminal voltage by using Discrete Wavelet Transform (DWT) and Daubechies mother wavelet. Aany possible event in the distribution network devided in two groups including : islanding and non islanding (Normal utilization, Faults include 3-ph, 2-ph, 2-ph to ground, 1-ph to ground in all buses, Load switching, DG switching, Capacitor banks switching) conditions with employing of DWT, requirement features by the third level of decomposition classified and accordingly events divided two groups islanding and non islanding. erformance of proposed method tested on IEEE 13 Node Test Feeder. This system have two different types of DGs that are synchrounous and asynchronous generators. The PSCAD/EMTDC from Manitoba HVDC research center sued to simulate the different scenario studied and analysing to be optimized in therms of indices such as: accuracy, speed, simplicity and reliability. By evaluation, it was determined that proposed method compared with conventional islanding detection method is able to islanding detecting in presence of MDG with high speed and high accuracy.

Keywords:

Islanding Detection , Discrete Wavelet Transform (DWT) , Distributed Generation (DG)