Instantaneous Power Theory for Active Filtering of High Displacement Power Factor Non-linear Loads

Abstract

Modern industrial plants make use of large numbers of variable frequency drives for a variety process controls. However, a drawback of this technology is that drives are a source of harmonic currents. This work designs and models in PSCAD, an electrical system typically encountered in modern industrial operations, where the load is composed of a large percentage of voltage-source converter drives. Attempts are made to provide mitigation by employing passive shunt harmonic filters. Following the benchmarking of these filters, a shunt active filter, whose control algorithm is based on the Instantaneous Power Theory, is connected to the system. The results obtained for the active filter are compared against results obtained for the passive filters. It will be shown that a shunt active filter is more suited solution for mitigation of harmonics generated by loads dominated by drives than passive filters.