Experimental Results of a Single-Phase Shunt Active Filter Prototype with Different Switching Techniques

This paper presents experimental results obtained with a developed single-phase shunt active power filter laboratory prototype operating with different switching techniques. This active filter can compensate harmonic currents and power factor in single-phase electric installations. Its power circuit is based on a two-leg IGBT inverter, with a single capacitor in the dc side, and an inductor in the ac side. Its control system is based on a simple stratagem that enables the use of the traditional Theory of Instantaneous Reactive Power (p-q Theory), originally developed to three-phase power systems, in single-phase systems. The experimental results are obtained for the active filter operating with two different switching techniques: Periodic Sampling (with variable switching frequency) and Pulse Width Modulation (with constant switching frequency) for two different frequencies (8 kHz and 16 kHz). Three different types of loads are used: linear RL load, rectifier with RL load, and rectifier with RC load.