The pseudo-continuous conduction mode four-switch buck–boost (FSBB) converter with negative valley inductor current is suitable for applications where zero-voltage-switching (ZVS) and voltage step-up and step-down are required. To improve its efficiency, many ZVS modulation schemes have been proposed to minimize the root mean square (rms) inductor current. However, when both input and output voltage ranges are wide, the three-dimensional (3-D) look-up table (LUT) with huge data quantity or the switching frequency with wide variation range is typically required in previous schemes. In this article, a ZVS modulation scheme with constant switching frequency and simple real-time calculation is proposed. Only with a 2-D LUT in a small range of input and output voltage, rms inductor current can be minimized. Moreover, the switching frequency is constant with the proposed scheme. In addition, ZVS conditions, which are accurate and simple, are derived to facilitate the minimization of rms inductor current. A 1500 W FSBB prototype with input and output voltage ranges of 200–400 V is built to verify the proposed modulation scheme and derived ZVS conditions.

中文翻译：

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宽输入输出电压范围、低电感电流的四开关降压-升压变换器恒频ZVS调制方案


具有负谷值电感电流的伪连续导通模式四开关降压-升压 (FSBB) 转换器适用于需要零电压开关 (ZVS) 和升压和降压的应用。为了提高其效率，人们提出了许多 ZVS 调制方案来最小化均方根 (rms) 电感器电流。然而，当输入和输出电压范围都很宽时，先前的方案通常需要具有巨大数据量的三维（3-D）查找表（LUT）或具有宽变化范围的开关频率。本文提出了一种开关频率恒定、实时计算简单的 ZVS 调制方案。只有在小范围的输入和输出电压下使用 2-D LUT，才能最大限度地降低均方根电感器电流。此外，所提出的方案的开关频率是恒定的。此外，还导出了准确且简单的 ZVS 条件，以帮助最小化均方根电感电流。构建了输入和输出电压范围为 200-400 V 的 1500 W FSBB 原型，以验证所提出的调制方案和导出的 ZVS 条件。