MULTI-LEVEL ACTIVE FILTER Russian patent published in 2010 - IPC G05F1/70 H02J3/18 H02M1/42 

FIELD: electricity.

SUBSTANCE: invention refers to the sphere of electrical engineering and may find implementation in transformation equipment, electric drives and other industries. Multiphase active filter includes a group of power elements electrically connected in three-phase configuration, circuit of pre-charging and controller, which controls voltage supplied from combination of power elements. Each power element includes inverter, having a pair of DC terminals, at least one capacitor is electrically connected parallel to inverter, and energy releasing circuit, which is electrically connected parallel to inverter. Energy releasing circuit of each power element independently controls DC voltage on element.

EFFECT: improved power ratio and reduced pulsations due to compensation of higher harmonics of output voltage.