For a low‐conversion ratio buck converter, the step‐down (unloading) transient lasts much longer than the step‐up transient for the same change of the load. Regarding this issue, an auxiliary bridge arm (ABA) multiphase buck converter with switching control scheme is proposed for the optimal unloading transient performance. With the ABA, the input voltage is reversely connected into the inductor current freewheeling loop during the unloading transient. In this case, the fall slew rate of the inductor current increases, because of the voltage across the inductor increase. Meanwhile, the capacitor‐charge balance theory is used to calculate the switching moment and achieve the minimum settling time and the voltage overshoots. Finally, a 12‐ to 3.3‐V two‐phase synchronous buck converter prototype is built. The experimental results show that the settling time and the voltage deviation are both improved over 50% compared with that of the average current sharing scheme and the time‐optimal control scheme.

中文翻译：

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基于辅助桥臂的开关控制，可实现多相降压转换器的最佳卸载瞬态性能

对于低转换比的降压转换器，对于相同的负载变化，降压（卸载）瞬变的持续时间比升压瞬变的持续时间长得多。针对此问题，提出了一种具有开关控制方案的辅助桥臂（ABA）多相降压转换器，以实现最佳的卸载瞬态性能。使用ABA，在卸载瞬态期间，输入电压反向连接到电感器电流续流环路中。在这种情况下，由于电感两端的电压增加，因此电感电流的下降斜率增加。同时，使用电容器-电荷平衡理论来计算开关力矩，并达到最小建立时间和电压过冲。最后，构建了一个12V至3.3V两相同步降压转换器原型。