120Hz output voltage ripple reduction of LLC resonant converter using resonant controller

A new method to reduce 120Hz output voltage ripple of LLC resonant converter using resonant controller is proposed in this paper. In the proposed control method, the resonant controller can give very high gain at this frequency, so it can reduce 120Hz output voltage ripple significantly. Employing the resonant controller in software, along with the conventional PI controller, the proposed technique can reduce 120Hz ripple without the additional circuit and cost. 2kW prototype experiment presents the results that verify the validity of the proposed method.