A Novel Configuration for a Cascade Inverter-Based Dynamic Voltage Restorer With Reduced Energy Storage Requirements

This paper introduces a new configuration for a cascade (H-bridge) converter-based dynamic voltage regulator in which the basic cascade converter is supplemented with a shunt thyristor-switched inductor. The proposed topology is shown to possess the ability of mitigating a severe and long duration voltage sag with a significantly smaller energy demand from the cascade converter. A suitable control system is designed, and the operation of the new device is analyzed using electromagnetic transients simulation as well as mathematical analysis. Simulation and experimental results are presented to demonstrate the feasibility and the practicality of the proposed novel dynamic voltage restorer topology.