Power Balance of Shunt Active Power Filter based on Voltage Detection: a Harmonic Power Recycler Device

A Shunt Active Power Filter based on voltage detection (VSAPF) behaves as virtual harmonic resistor at harmonic frequencies. Thus, some amount of harmonic active power is absorbed by the VSAPF. If the VSAPF's power losses are smaller than the harmonic active power intake, the difference will be stored as energy in the DC-bus capacitor. It follows that the stored energy in the capacitor can be transformed to fundamental active power and returned back to the power system. In other words, it means a VSAPF acting as harmonic power recycling device. This paper presents the mathematical description of such power transformation and shows an ultra-low losses VSAPF design that makes the harmonic power recycler feasible. The proposed VSAPF is validated by computer simulation. Furthermore, experimental results that show the capability of the VSAPF to absorb harmonic active power and to reduce the harmonic voltage distortion (T HD
_V
) in a distribution network are also presented.