【摘要】 针对四开关Buck-Boost(FSBB)变换器在传统控制策略下控制方法复杂、整机运行效率不高的问题,提出了一种减少控制变量加变频的改进三模式控制策略。分析了改进三模式控制策略下变换器的工作原理,详细介绍了在宽输入范围下通过该控制策略来实现变换器高效运行的控制方法。以数字控制芯片TMS320F28027为核心搭建了1台输入30～66 V、输出48 V/4 A的实验样机。实验结果表明,所提出的改进三模式控制策略可使FSBB变换器在宽输入电压和全负载范围内实现开关管ZVS,并在满载时效率最高可达97.5%。更多还原

【Abstract】 To solve the problem of high complexity and low efficiency of four switch Buck-Boost(FSBB)converter based on the traditional control strategy,an improved tri-mode control strategy with reduced control variables and variable frequency technology was proposed. Then,the working principle of the novel control strategy was analyzed and the control method for high efficient operation was introduced in detail with the wide input voltage range. Finally,a prototype with input 30～66 V and output 48 V/4 A was built based on the digital control chip TMS320F28027. The experimental results show that the improved tri-mode control strategy enables the FSBB converter to realize zero voltage switching(ZVS)and higher efficiency under the situation of a wide input voltage range and the whole load range,with an efficiency up to 97.5% at full load.更多还原