A New Control Method of Suppressing the DC-Capacitor Voltage Ripple Caused by Third-Order Harmonic Compensation in Three-Phase Active Power Filters

This paper proposes a new control method suitable for active power filters, which can reduce the dc capacitor voltage ripple associated with the third-order harmonic current compensation. The proposed method superimposes a negative-sequence fundamental current on the compensating current to cancel out the active power ripple caused by the third-order harmonic current. As a result, the proposed method has the capability to eliminate the dc capacitor voltage ripple oscillating at double the source frequency. Experimental results obtained by a 10-kW three-phase diode rectifier load verify the validity of the proposed method. The proposed method exhibits a small dc capacitor voltage ripple reduced to 43% of that using the conventional method. © 2017 Wiley Periodicals, Inc.