A sag and harmonic compensation method without harmonic detection for dynamic voltage restorer

In this paper, a novel supply voltage harmonic mitigation method using a simple DVR without harmonic detection is proposed. In contrast to the conventional DVRs control methods, the proposed method realizes two independent control objectives at fundamental and harmonic frequencies without couplings, with the adoption of the proposed voltage controller with two independent inputs focusing on different frequency regions. The fundamental voltage control is adopted to compensate voltage sags. The harmonic control loop compensates the load side harmonic voltage simultaneously without any harmonic extraction. Verification results are provided to validate the correctness of the proposed system.