A Novel SPLL and Voltage Sag Detection Based on LES Filters and Improved Instantaneous Symmetrical Components Method

The software phase-locked loop and the voltage sag detection algorithm are the two key factors to evaluate the performance of a dynamic voltage restorer, whose dynamic response is usually impacted by phase jump, voltage unbalance, and harmonics of the grid voltage. This paper proposes a novel algorithm based on the combination of least error squares filters and an improved instantaneous symmetrical components method. Hence, a detailed theoretical procedure is first presented. Then, the simulation model is built in MATLAB/SINMULINK. To verify its effectiveness, a series of comparison and analysis have been carried out. Also, a 10-kV/2-MVA prototype is developed with a voltage sag generator platform. Finally, experiments have been done and the results show that the novel algorithm has an improved dynamic response compared with the traditional methods.