Design and simulation of dynamic voltage restorer (DVR) for power quality improvement

Abstract

Power quality (PQ) is one of the main issues faced in the present era. The PQ issues such as voltage sags, swells, harmonics, and unbalance as well as the impact on sensitive loads are often occurred in any power distribution system. To tackle the issues, a powerful dynamic voltage restorer (DVR) is commonly installed. However, the existing control algorithms for DVR are found to be complex, potentially increases computational burden to the controller. Therefore, in this paper, a new simplified control algorithm which utilizes the strengths of synchronous rotating frame (SRF) and phase-locked loop (PLL) concepts, is proposed to better manage operation of DVR. The DVR system is modelled and simulated by using MATLAB/Simulink platform. Performance of the newly proposed algorithm for DVR is tested in three-phase system with voltage sags, swells, harmonics and unbalances conditions. From the findings, it can be concluded that the proposed algorithm for DVR which installed in a three-phase power distribution system effectively mitigated the voltage sags, swells and unbalances conditions and, for harmonics condition, it is found to be able to minimize and contain the harmonic contents within the acceptable level.