Synchronous PI decoupling control scheme for dynamic voltage restorer against a voltage sag in the power system

A new control strategy for driving the dynamic voltage restorer (DVR) is proposed. It is based on the synchronous PI decoupling control strategy which features fast response and low steady state error. Therefore, the proposed control strategy shows the faster action against voltage sag and guarantees more enough compensation for the sagged supply voltages. In addition, since the currents flowing through the ripple filter inductor are used as the supplementary control variables, it is possible to protect the switching power device against the surge current in the proposed control strategy. The experimental results implemented with TMS320C3x DSP control unit are shown to validate the effectiveness of the proposed control strategy.