Three detecting methods of transient power quality disturbances in DVR

Dynamic voltage restorer (DVR) is widely applied to industry because it can reduce the impact of voltage disturbance to sensitive loads. The three detecting methods to extracted distortion components of DVR based on Hilbert transform, wavelet transform, and the instantaneous reactive power theory produce are introduced in details, respectively. Comparisons of working performance among these difference detecting methods of DVR are applied to power quality disturbance analysis under various run conditions. The results show that the method of Hilbert transform doesn´t detect distortion voltage of containing harmonic; the method of instantaneous reactive power theory can detect harmonic components, but doesn´t detect distortion voltage of containing voltage sags; the method of wavelet transform has best detecting performance under different run conditions. Simulation results verify three detecting methods´ applicability and effectiveness in DVR system.