Historical review of parallel hybrid active power filter for power quality improvement

Hybrid active power filter (HAPF) has already been an effective and widely-used method for power quality improvement. This paper presents historical review and developing progress of the HAPFs´ functionalities as harmonic and reactive power compensation. The structures of HAPFs are discussed in different historical periods, and divided into four developing pattern: parallel active part with parallel element, parallel active part with series element, b-shape, and three-phase four-wire structure. It is aimed at making a comprehensive analysis of HAPFs´ historical developing tendency in structure and function design. The future possible developing guidelines are discussed as conclusion in the last.