Structures and control of a dynamic voltage regulator (DVR)

The paper presents the structures and control of a dynamic voltage regulator (DVR) that injects voltage in series with a distribution feeder. This is a power electronic controller that can protect sensitive loads from disturbances in the supply system. It is demonstrated that this device can tightly regulate the voltage at the load terminal against imbalance or harmonic in the source side. It is stipulated that the device does not supply any real power in the steady state. To accomplish this, the behavior of the device is first studied through steady state analysis and then this analysis is extended for the transient operation. Two suitable structures in which the DVR is realized by voltage source inverters along with filter are also discussed. A deadbeat output feedback controller for these DVR structures is designed. Extensive simulation results are included to illustrate the operating principles of the DVR.