Robust control design for multi-functional DVR implementation in distribution systems using quantitative feedback theory

One of the most effective tools to prevent the voltage amplitude from a sudden change in distribution systems is the dynamic voltage restorer (DVR). In this paper, a novel voltage control loop using quantitative feedback theory (QFT) is proposed for the emergency control of distribution systems by means of DVR. The proposed multi-functional DVR control strategy is applied to a three-phase fault which is the main cause of the worst voltage sag. The simulation results clearly show that this control strategy would be able to effectively regulate the voltage, especially when the parameters of the system change. The ability of the proposed DVR to limit the downstream fault current has been also examined. This current limitation will restore the Point of Common Coupling (PCC) (the bus to which all feeders are attached) voltage and also protect the DVR itself.

► A novel voltage control loop for distribution systems by using DVR is proposed. ► Quantitative feedback theory is used to design this voltage control. ► This control strategy is able to consider the parameter variations. ► The ability of the DVR to limit the downstream fault current has been examined. ► The simulation results verify the effectiveness of the proposed DVR.