Hybrid Active Power Filters

Abstract

In this chapter, the hybrid active power filters are discussed. In Sect. 4.1, the development of hybrid active power filters (HAPFs) is initially presented. Then different hybrid active filter (HAPF) topologies have been compared and discussed in details in Sect. 4.2. Among them, LC-coupling HAPF (LC-HAPF) topology is being chosen for further investigation in this chapter because it can offer the lowest cost, size and weight, and has potential to provide dynamic reactive power compensation. Owning to the limitations or existing problems of the LC-HAPF as discussed in Sect. 4.3, this chapter aims to provide their corresponding solutions one by one. In Sect. 4.4, the harmonic resonances prevention, compensation capabilities and system robustness of the LC-HAPF are studied and investigated based on the deduced circuit model. Then different dc-link voltage control techniques for the LC-HAPF while performing dynamic reactive power compensation are explored and presented in Sect. 4.5. A novel adaptive dc-link voltage control technique for LC-HAPF in reducing switching loss and switching noise under reactive power compensation is proposed in Sect. 4.6. This adaptive control technique is also applied to active power filter (APF) for investigating switching loss and switching noise reduction. In Sect. 4.7, a minimum inverter capacity design for LC-HAPF in dynamic reactive power and current harmonics compensation is also studied and discussed. Finally, the design and performance of a LC-HAPF experimental system will be presented and discussed in Sect. 4.8, which can effectively compensate both dynamic reactive power and current harmonics in the three-phase four-wire distribution power systems.