EPLL based controller for voltage harmonic mitigation in grid connected wind systems

Voltage harmonics are very important voltage disturbances which induce overheating of transformer/generator, connection loss and rise of current rating in grid connected wind energy systems. In this paper, Enhanced Phase Locked Loop (EPLL) based controller method is proposed to generate reference signals of voltage harmonics at grid-side voltages. In order to achieve the harmonic compensation, EPLL based controller method is tested to compensate voltage harmonics for balanced and unbalanced conditions in Dynamic Voltage Restorer (DVR) tied grid-connected wind energy systems. The performance results of EPLL based controller demonstrate that it is a very effective technique for harmonic compensation under steady-state and transient conditions.