Control strategy of three-phase four-arm active power filter

Three-phase four-arm active power filter adds one arm to the three-phase three-wire active power filter. It adds a control variable but has the same control object. The paper introduces the control strategy of the three-phase four-arm APF. Then it analyzes Three-Dimensional Space Vector Pulse Width Modulation (3D-SVPWM) in the static abc coordinates. Finally, the simulation and experiment results verify the control strategy with high compensate precision of the harmonic current.