A novel method of active filter control using repetitive control

The line current detection type AF is attractive to compensate using only one current sensor and only one AF compensates all harmonics. However, it is difficult to compensate harmonics completely due to stability and a resonance problem. We propose a new method using the repetitive control for the line current detection type active filter. Aiming at a periodicity of the harmonics, the repetitive control is applied to the AF control. The line current harmonics is detected and memorized at every sampling time during the fundamental cycle. The memorized data are given to a reference of the AF after a fundamental period. The AF output current reference is optimized and the deviation in the line current harmonics gradually decreases by repeating the method. Good simulation results of the harmonics compensation by the proposed method are presented