Original Research Article
Year: 2015 | Month: May | Volume: 2 | Issue: 5 | Pages: 234-241
DFHCI Based Wavelet Lifting Scheme for Islanding Detection
M. Shalini1, T. Manjunath2
1PG Student/EEE, 2Assistant Professor/EEE,
PSV College of Engineering & Technology, Tamil Nadu, India.
Corresponding Author: M. Shalini
ABSTRACT
This paper proposes a novel method of wavelet lifting based three-phase grid impedance detection method based on dual-frequency harmonic current injection for islanding detection. Using wavelet transforms always results in time localization and hence the instant of islanding also can be detected with our proposed method. When the load mismatch occurs, it clearly reveals that there exists an impedance mismatch in power distribution systems. This is a serious problem in power delivery. Hence in this method based on dual-frequency harmonic current injection (DFHCI) is injecting two non-characteristic symmetric harmonic currents, and then according to the different harmonic voltages caused by different frequency harmonic currents, all three-phase impedances can be calculated accurately. The implementing algorithm of the presented method is derived and its performance is analyzed in detail. Simulation and experiments are carried out under grid impedance balanced and unbalanced conditions. Theoretical analysis and experiment results proved that the proposed method is practically feasible by MATLAB.
Index Terms: Wavelet lifting, Harmonic current injection, Impedance unbalance, dual frequency.