A novel control algorithm for cascade shunt active power filter

In this paper a novel control scheme of cascade shunt active power filter (CSAPF) is presented. This work is motivated by the fact that the compensation ability of traditional active power filter is limited by the voltage capability of the power devices. While the converter with cascade topology has been put into practical use for years especially in high voltage and high power drives. The application of such converter to active power filter is hindered by the problem of voltage unbalance of separate DC capacitors that leads to system instability. This paper deals with the design and implementation of a new digital controller for CSAPF. Finally experimental results obtained from a laboratory system developed in this paper are presented to verify the viability and effectiveness of the proposed control algorithm.