Auto tuned robust active power filter for power quality improvement under fast load variation

Widespread applications of power electronic-based loads continue to increase concerns over harmonic distortion. The current harmonics produced by non-linear loads result in voltage distortion and leads to various power quality problems. Moreover these non-linear loads are not fixed and change randomly. However classic filters may not have satisfactory performance in such fast varying conditions. This paper presents an auto tuned active power filter for harmonic minimization and reactive power compensation of non-linear load under fast load variation condition. Improving dynamic behavior of shunt active power filter fuzzy logic controller is used to tune PI controller coefficients and make it robust under random load variation. The proposed methodology is extensively tested for wide range of variable load current under stochastic conditions and results are found to be quite satisfactory to mitigate harmonics and reactive power components from the utility current.