A novel repetitive controller for nk±m order harmonics compensation

This paper presents a novel repetitive control (RC) scheme called nk±m order harmonic repetitive control (nk±m RC), which provides a universal formula for various RC schemes, such as regular RC, odd-harmonic RC, 6k±1 order harmonic RC, and so on. The proposed control scheme can achieve zero-error tracking or perfect disturbance rejection for any specific nk±m order harmonics. Compared with the regular RC, nk±m RC occupies less data memory and offers faster error convergence rate. It also yields very low total harmonics distortion (THD) and very high tracking accuracy. An application example of nk±m RC controlled three-phase PWM inverter demonstrates the effectiveness of the proposed nk±m RC scheme.