The LLC resonant converter employed in battery chargers is considered in this paper. A control strategy called NOVL mode has been proposed. This method integrates both PFM and PSM which can handle a wide voltage range. In this study, the input voltage is assumed to be fluctuated. When the control state changes due to the fluctuation of the input voltage, a surge current is observed in the output current. Therefore, OVL mode is proposed as a new control state change method to curtail the surge current in the charging process, and the experimental results confirmed the surge current reduction.
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