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

Abstract

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.

Active Power Conditioners to Mitigate Power Quality Problems in Industrial Facilities

“…Furthermore, in three-phase four wire systems it allows to balance the currents in the three phases, and to eliminate the current in the neutral wire [15][16][17]. Figure 2 presents the electrical scheme of a Shunt Active Power Filter for a three-phase power system with neutral wire.…”

“…Passive filters have been used as a solution to solve harmonic current problems, but they present several disadvantages, namely: they only filter the frequencies they were previously tuned for; their operation cannot be limited to a certain load; the interaction between the passive filters and other loads may result in resonances with unpredictable results [6]. To cope with these disadvantages, in the last years, research engineers have presented various solutions based in power electronics to compensate power quality problems [6][7][8][9][10][11][12]. These equipments are usually designated as Active Power Conditioners.…”

Single-phase Shunt Active Filter interfacing renewable energy sources with the power grid

“…The compensation currents in the a-b-c coordinates are determined by applying the inverse Clarke transformation to the currents in the --0 coordinates, as demonstrated in (7). The original p-q Theory is only applicable to three-phase systems.…”

A control strategy for a three-phase four-wire shunt active filter

“…The applied switching technique is denominated periodic sampling [11]. It is a well known technique, with reasonable results, and it is very simple to be digitally implemented.…”