The study of three-phase four-wire shunt active power filter

A simplified mathematical method is present to detect harmonic and reactive current used in three-phase four-wire shunt active power filter (APF). In order to validate the detection method, an experimental prototype of three-phase four-wire shunt APF adopting DSP chip TMS320F2812 was established in laboratory. To compensate the harmonic and reactive current precisely, the double-loop control of internal current loop and external voltage loop was adopted. The results of simulation and experiment show that the method can accurately detect real-time grid harmonic and reactive current and compensate it well.