混合动力车用全数字电流控制型双向DC/DC变换器

Digital-Current-Controlled Bi-Directional DC/DC Converter in the Hybrid Electric Vehicle

立足于混合动力车用双向DC/DC变换器,阐述了车辆对应不同的工况下,变换器的各种工作模式,引出了全数字电流控制型双向DC/DC变换器所面临的一些技术难点。通过理论分析和数学推导,并充分考虑工程应用中的实际因素,提出了基于平均电流的控制算法以及断续同步整流模式的数字控制策略,该方法利用单一电流采样电阻完成变换器的多模态双向恒流控制,并且在反向小电流区域内进一步提高了变换器的效率。依据所提出的控制策略,研制了适合于48V蓄电池供电的800W试验样机,试验结果证明了此方法的有效性和可行性,可应用于混合动力车驱动系统中。

This paper focuses on the most important aspects of the bi-directional DC/DC converter in the hybrid electric vehicle（HEV） for the project applications.The different operating modes of converters are introduced under all HEV＇s work conditions. Based on summarization, the demerits including low efficiency at light load and the uncontrolled discontinuous current when charging for the battery are derivated. Through theoretical and mathematical analysis, a new algorithm of average current controlling and digital control method in discontinuous synchronous rectifier mode with a single current sensor resistance are proposed to realize the multi-mode bi-directional DC/DC converter. At the same time, the 800W prototype using proposed technology is implemented for 48V HEV application in order to verify the operational principles and advantages that improved synchronous rectifier inverse-boost converter light load efficiency. Effectiveness and feasibility of the new proposed control strategy is verified by experiments.So it can be applied to hybrid electric vehicle drive system.