Power Quality Enhancement in Grid Connected Wind Power System Based on Dfig Using Fuzzy Controlled Upqc

The renewable energy resources rule the world of power generation. Now-a-days wind farms are encouraged for up gradation of energy production, as the wind power is dirt free, readily available renewable alternative. The integration of wind farms with power grid leads to Power Quality (PQ) issues such as voltage sag, swell, flicker, harmonics etc. Most of the industrial and commercial loads are of non-linear type which produce the starting place of harmonics. As 70% of PQ problems are voltage sag which is one of the most severe disturbances to sensitive loads. The outcome issues are pronounced at both sides consumer sector as well as production sector which get affected with poor quality of power. Among many of custom power devices, Unified Power Quality Conditioner (UPQC) is the only device which can be used to diminish both voltage sag and current harmonics. This paper analyzes PQ problems, voltage sag and current harmonics due to the interconnection of grid connected wind turbine and also provides PQ enhancement by introducing UPQC. For the performance improvement of UPQC, a novel control strategy using Fuzzy Logic Controller (FLC) is proposed which eliminates the drawback of using fixed gains in conventional PI controller. From the simulation results, by comparing controller performances, the proposed fuzzy controlled UPQC provides effective and efficient mitigation of both voltage sag and current harmonics than the conventional PI controlled UPQC , thus making the grid connected wind power system more reliable by providing good quality of power.