A simple control scheme for hybrid active power filter

A simple control scheme for hybrid active power filters connected in parallel is presented and analyzed in this paper. The hybrid active power filter combines the compensation characteristics of resonant passive and active power filters. The series active power filter is implemented with a three-phase PWM voltage-source inverter. The proposed scheme is able to compensate displacement power factor and current harmonics simultaneously. The combination of passive and active power filters allows a better performance compensation of high power voltage nonlinear loads. The proposed control scheme is discussed in terms of principles of operations under steady state and transient conditions. The design and implementation of the power and control circuits are reported. Finally, key predicted results are verified experimentally on a 5 kVA prototype model.