Application of repetitive control for removal of harmonic distortions from inverter output

It is mandatory to keep total harmonic distortion in output of most inverters below a prescribed limit. The harmonic distortions caused due to non-linear loads may not get corrected by simple PID controllers. Repetitive controllers are more effective in such situations. Often repetitive controllers are used as add-on block to the conventional PID controller. Design of repetitive controller can be easily implemented on digital platform. Some controller parameters may have to be decided on trial and error basis.