宽输入双有源桥变换器移相变频控制策略研究

RESEARCH ON VARIABLE FREQUENCY PHASE SHIFT HYBRIDCONTROL STRATEGY OF DUAL ACTIVE BRIDGECONVERTER WITH WIDE INPUT VOLTAGE

重点分析三重移相控制下宽输入工况对双有源桥DC-DC变换器特性的影响,分别推导宽范围输入电压情况下软开关范围、电流峰值和电流有效值随开关频率变化的理论表达式。在此基础上,提出一种移相变频混合控制策略,通过调节开关频率扩大双有源桥DC-DC变换器的软开关范围,并降低电流峰值和电流有效值,提高变换器的整体效率。最后,搭建一台基于SiC器件的1 kW双有源桥DC-DC变换器样机验证所提控制策略的有效性。

With the rapid development of the new energy industry,the application demand of a wide range of conditions is more and more extensive.As the classical topology of bidirectional DC-DC converter,dual active bridge DC-DC converter has the problems of decreasing soft switching range,increasing current peak value and current RMS value in wide range applications.Therefore,this paper focuses on analyzing the influence of wide input conditions on the characteristics of dual active bridge DC-DC converter under triple phase shift control,and deduces the theoretical expressions of the variation of soft switching range,current peak value and current RMS with switching frequency under wide input voltage.On this basis,a phase-shifting variable frequency hybrid control strategy is proposed.By adjusting the switching frequency,the soft switching range of the dual active bridge DC-DC converter is extended,and the current peak value and current effective value are reduced,and the overall efficiency of the converter is improved.Finally,a prototype of a 1 kW dual-active bridge DC-DC converter based on SiC device is built to verify the effectiveness of the proposed control strategy.