Multilevel Converter-based Dynamic Voltage Restorer for Mitigation of Voltage Disturbance in Distribution Network

In today’s power systems, one of the main problem is power quality. The emergence of complex equipment and excessive use of power electronic devices, have made them highly dependent on the quality of the supplied power, that has increased its importance to both suppliers and consumers. Sensitive equipment’s can be damaged due to voltage sag, voltage swell and harmonics present in the power system, which are mostly occurring power quality issues. This research focuses on enhancing the performance of a DVR under extreme sag and swell conditions by using a multilevel converter. In the proposed approach, we first employ the Synchronous Reference Frame (SRF) technique with positive sequence detection, followed by the integration of a Proportional-Integral (PI) controller, and lastly utilization of a Cascaded H-Bridge (CHB) five-level converter. SRF technique is employed to accurately detect and extract the fundamental components of voltage disturbances, enabling precise compensation and restoration of distorted waveforms. PI controller ensures accurate voltage regulation and robust control performance. Cascaded H-Bridge MLC topology is utilized to generate compensating voltage with increased voltage levels as compared to the conventional two-levels, reduced total harmonic distortions (THD), and improved power quality. The proposed technique is compared with traditional converter and control methods using MATLAB/Simulink simulations. The result shows significant improvements in voltage restoration, reduced THD and enhanced dynamic response under extreme sag and swell conditions. This research contributes to the advancement of power quality technologies, providing a reliable and efficient approach to voltage restoration in power distribution systems.