Harmonic and Reactive Power Control using a Hybrid Active/Passive Power Conditioner based on a Square Wave Source

Control of harmonic and reactive power typically requires high bandwidth, high power converters. As these are conflicting requirements, the cost of such an installation is typically high. In this paper, a hybrid power quality compensator is proposed which consists of a square wave inverter for reactive power compensation combined with a hybrid active/passive filter for harmonic compensation. The filter removes the harmonics produced by the load and the square wave inverter, resulting in a sinusoidal, unity power factor supply current. A suitable control strategy is proposed based on synchronous reference frame transformations and a PI regulator. Control of the reactive current is achieved by varying the bus voltage of the square wave inverter to vary the voltage across the coupling inductor. A simulation model is developed in SIMULINK and used to demonstrate the operation of the compensato