This paper proposes a novel two-stage phase-shift optimization strategy to reduce DC bus ripple current in a two-phase cascaded boost converter. Conventional 180° interleaving causes frequency mismatch between the front-end and back-end stages, degrading ripple cancellation. To address this, the proposed method first derives an optimal front-end phase angle (αopt) to match stage frequencies and shape the current waveform. Subsequently, an optimal back-end phase angle (βopt) aligns the back-end input current peak with the center of the shaped front-end current’s high interval, achieving precise synchronization. This minimizes instantaneous current deviation and cancels charge variations. Experiments on a 1 kW prototype demonstrate a 21.2% reduction in RMS ripple current compared to conventional methods. System efficiency improved by 0.42–0.49% due to reduced capacitor losses. The strategy enhances reliability by alleviating thermal stress while contributing to high efficiency and power density in power conversion systems.
Kim et al. (Sun,) studied this question.