Comparative Performance of Wiener Filter and Adaptive Least Mean Square-Based Control for Power Quality Improvement

This paper presents a three-phase shunt active power filter (SAPF) for mitigating power quality problems at the distribution level. Power quality problems such as harmonics, reactive power, and unbalancing in the loads are mitigated for both unity power factor and voltage regulation modes. A three-phase voltage-source converter (VSC) is used as an SAPF for performing all these functions. The linear optimum discrete time filtering technique namely Wiener filtering-based control algorithm is developed for the extraction of reference supply currents from distorted load currents. The performance of Wiener filter is compared with least mean square (LMS) adaptive filter-based control algorithm. Experimental validation of proposed control algorithm has been performed on a prototype developed in the laboratory. The filtering action of SAPF is able to achieve the total harmonic distortion (THD) of supply current within the limit specified by an IEEE-519 standard.