Wavelet-based dynamic voltage restorer for power quality improvement

This paper presents a novel method for power quality improvement employing wavelet analysis. A wavelet filter bank is used to detect and classify various disturbances experienced by the voltage on the load side. A dynamic voltage restorer is used to compensate the voltage under disturbance conditions and maintain the rated load voltage. The input and the output voltages of the DVR are both controlled by the wavelet filter bank outputs. The approximations control the input voltage to the AC-DC converter. The control pulses of the DC-AC inverter are controlled by the details. Different types of disturbances are simulated to test the performance of the proposed control scheme. The proposed wavelet based control scheme successfully provided fast and accurate voltage restoration following any form of transient disturbances.