Analysis of Three-Phase Four-Wire Shunt Active Power Filter Topologies Implemented Using Single-Phase Full-Bridge Inverters

Abstract

This paper presents a comparative analysis involving two different topologies of three-phase four-wire shunt active power filters (SAPFs), such that load current harmonic suppression, as well as load reactive power compensation are carried out, resulting an effective power factor improvement. Both SAPF topologies use three single-phase full-bridge (1P-FB) inverter units. In the first, named 3FB-C-DC-Bus topology, the 1P-FB inverters share a common DC-bus voltage, while in the second, named 3FB-I-DC-Bus topology, each 1P-FB inverter unit has an independent dc-bus. Independent current control strategy is adopted for computing the current references of each inverter unit, meaning that the grid currents can be individually controlled. In other words, the three-phase system can be treated as three independent single-phase systems. Apart from accomplishment of static and dynamic performance evaluations, which are performed by means of computational simulations, the amount of passive and active devices needed to build both the SAPF structures is also measured and evaluated. As a result, the best decision for choosing the structure with the best cost effectiveness is allowed.