A repetitive-based controller to compensate for harmonic distortion in the output voltage ora boost converter

A novel repetitive based-control strategy is proposed for the Pulse Width Modulated (PWM) boost converter to compensate the output voltage ripple due to the harmonic distortion present in the input voltage. Repetitive control has shown to be a useful tool for tracking of periodic reference signals and for compensation of periodic disturbances, in other words, for harmonic compensation. The structure of the proposed controller is preserved as close as possible to the conventional one, which includes outer and inner control loops. Thus, in the proposed controller, the repetitive strategy appears as a refinement term added to the inner control loop. We show that the repetitive strategy can be built using a single analog delay integrated circuit, thus simplifying enormously the implementation. The repetitive strategy is able to cancel almost every remaining harmonic distortion component while maintaining an acceptable dynamical performance and without inclusion of additional hardware in the power stage. Experimental results on a boost converter board, using a poorly regulated voltage source, are presented to assess the performance of our approach.