Digital control of active power line conditioner based on instantaneous reactive power theory

This paper presents a shunt active power filter application mainly for source current harmonic elimination. The proposed control method is based on instantaneous reactive power theory. A three-phase voltage source inverter bridge with a dc bus capacitor is used as an APF. It requires measuring the source currents with reduced number of current sensors than the existing methods. The source currents are exactly in phase with the line voltages and approximately in sinusoidal waveform after reactive power and harmonic compensation. Three hysteresis band current controllers are employed to derive switching signals to the shunt Active Power Filter. A three-phase diode rectifier with resistive-inductive loading is employed. MATLAB/SIMULINK power system toolbox is used to simulate the proposed system. Simulation results are presented and the improvement in the supply current is shown in the paper.