An indirect current control of hybrid power filter for varying loads

This paper presents an indirect current control scheme of parallel hybrid power filter system (PHPF) with self-supporting dc bus to eliminate harmonics generated by the nonlinear load. The PHPF system consists of a shunt passive filter with an active filter (AF) in series with it connected at the point of common coupling (PCC) in parallel with nonlinear load. The AF is realized using a three-phase voltage source inverter (VSI) with self supported dc bus. The compensation principles and dynamics of the system are discussed in detail. A proportional-integral (PI) controller over average dc bus voltage of the AF connected in series with passive filter is used for the control of the PHPF. The modeling equations of the PHPF are derived for compensation of harmonics generated by a three-phase rectifier load. The effectiveness of proposed control technique of the PHPF is demonstrated through simulated results under the dynamics of change of loads.