An efficient detection of compensation for DVR considering decaying dc component

A dynamic voltage restorer (DVR) is a power-electronic controller that can protect sensitive loads from disturbances in the supply system. It is a static series compensator (SSC) suitable for protecting industrial plants against voltage sag. Considering the decaying DC component in fault signal impacts the real-time performance and compensation accuracy of voltage compensation detection. This paper presents a semi-period algorithm and a three-point algorithm. Both of the two algorithms can quickly extract fundamental component from fault signal. After the fundamental positive-sequence voltage is extracted by the instantaneous decomposition link, the voltage compensation can be calculated through the direct-detecting algorithm. The simulation results prove the two algorithms can filter the decaying DC component and just needs a small amount of calculation. It has great potential for practical applications.