Design of a dynamic voltage restorer with cascade inverter

This paper presents a DVR system using the cascade inverter to perform an effective compensation for the voltage sag. By splitting the DVR-injected active and reactive power from different inverter unit, the designated dynamic voltage restorer not only provides the battery a ripple-free dc link to extend the lifetime of battery, but also offer a flexible way to design the capacitor bank in the system realization. This method has been tested through computer simulation and hardware validation. Test results help consolidate the feasibility of the approach for the applications considered.