Analysis and design of a cost-effective series connected AC voltage regulator

An improved series connected AC voltage regulator for low cost applications is considered. The proposed system comprises a diode rectifier and a switching inverter stage that has the capability of continuously regulating sustained voltage swells and sags. It maintains the desired load voltage level with only unidirectional energy transmission, which is different from conventional units that can regulate only one direction of voltage fluctuation with the same circuit structure. Theoretical analysis has been achieved based on the power flow theory. Prototype case studies have demonstrated the effectiveness and performance of this voltage regulator.