A sliding mode control of an active power filter

The main difficulty to control an active filter is linked to the nature of the load, and especially when the load is capacitive. In this paper, to solve this problem, a sliding mode control is conceived by imposing a desired dynamics in the mains current. A passive filter in series with the load is introduced to reduce the instabilities due to source output inductance. The sliding mode control allows us to compensate the harmonic distortion and phase displacement of the line current, even correcting capacitive loads.