
38-16 Power Electronics and Motor Drives
38.5.2 Active Power Filter
To overcome the limitation of passive lters, APFs were developed to provide better dynamic control
of current harmonics and voltage distortion control. is is achievable thanks to the developments in
solid-state switching devices and control technology in recent years. APFs can be classied based by a
number of elements in topology, supply system, and the types of converter used in their circuits. ey are
single-phase (two-wire), three-phase three-wire, and three-phase four-wire voltage- or current-source
inverters used to generate the compensating voltage or current that ...