<p>This paper investigates the control strategy of a two-stage on-board charger for electric vehicles to enhance power quality and output voltage stability. Firstly, a mathematical model of a four-phase interleaved totem-pole bridgeless power factor correction converter is developed, based on which an integral sliding mode current control strategy based on an improved chattering-weakening nonlinear method is proposed. The strategy suppresses the over-zero current spikes, improves the current quality, and enhances the system’s robustness. Secondly, the mathematical model of the CLLLC resonant converter is established, and a nonlinear active disturbance rejection voltage control strategy based on improved anti-integral saturation is proposed. This strategy has been shown to enhance the system’s stability and robustness through improvements to the anti-integrating saturation design and nonlinear filtering function. Finally, the effectiveness of the proposed control strategy in improving the quality of the input current and enhancing the immunity of the output voltage is validated through both simulations and experimental results.</p>