Current Reference Control for Shunt Active Power Filters Under Unbalanced and Distorted Supply Voltage Conditions

This paper proposes a current reference control method for shunt active power filter under unbalanced and distorted supply voltage conditions. The method uses the Kalman filter and the symmetrical component method to obtain the fundamental sequence component of the supply voltage. The Fryze-Buchholz-Dpenbrock method is used to decompose the load current under the reference of the fundamental positive-sequence voltage to obtain the reference value of the compensation current. The method is characterized without need of coordinate transformation, simple calculation, and clear physical meaning. The harmonic current, reactive current and negative sequence current can be compensated at the same time even under the condition of unbalanced supply voltage. The proposed method is compared with the traditional method under various experimental conditions to prove the validity and accuracy of the proposed method. The results show that the proposed method has wider applicability.