确保被动电流平衡交错多相双向DC-DC变换器在相参数失配下实现ZVS的设计方法

In interleaved multiphase bidirectional DC to DC converters operating in triangular current mode (TCM) at high frequencies, achieving zero voltage switching (ZVS) and managing current imbalance are critical for system reliability and robustness. To meet these requirements, passive current balancing, using only a single low-speed current sensor and a current control loop, offers a cost-effective solution. However, their performance is sensitive to phase parameter mismatches, such as gate driver delay skew and discrepancies in phase inductance, which can lead to current imbalance and ZVS failure. Although perfect current balancing is not strictly required, maintaining ZVS is essential, as its loss leads to substantial switching losses and thermal stress. This study proposes a design method that ensures ZVS under worst case mismatch conditions inherent to passive balancing. The method allows current imbalance within acceptable limits while preserving soft switching. A mathematical model is developed to characterize phase current behavior under mismatch and guide the design of switching frequency and dead time. Experimental validation on a 360W three-phase interleaved bidirectional DC-DC converter demonstrates that even with up to 39.5% phase current deviation, the converter maintains ZVS, thermal stability, and efficient operation. The proposed method offers a robust, scalable, and low-complexity solution for real-world applications.