一种用于轻度混合动力汽车的高效双向DC/DC的研制

Design of a High-efficiency Bi-directional DC/DC Converter for Mild-hybrid Vehicles

首先分析了"12+48 V"轻混系统的优势以及该系统中的重要部件,48/12 V双向DC/DC变换器,随后对该双向DC/DC变换器的研制进行了分析。提出了一种应用同步整流技术、结构简单、系统成本低、控制方法简单的主电路拓扑结构,并详细分析了电路的工作原理。选用了凌力尔特公司新开发的双向DC/DC控制芯片LTC3871,结合外部电路设计,完成了一款高效双向DC/DC变换器的研究与制作,最后给出了制作的实物及实物测试波形。

The advantages of a 12 ＋48 V mild-hybrid system were analyzed at first, together with one of its important parts, i.e., a 48/12 V bi-directional DC/DC converter. Then, the design process of this converter was analyzed, and a main circuit topology with synchronous rectification technology was presented, which had a simple structure, low system cost, and simple control method. Moreover, the working principle of the circuit was analyzed in detail. A bi-directional DC/DC control chip, i.e., LTC3871 （developed by Linear Technology Corporation）, was adopted. With the com-bination of external circuit design, a high-efficiency bi-directional DC/DC converter was fabricated. Finally, the prototype was tested through experiments.