原边双绕组耦合的高效无死区直流变压器

High Efficiency DC Transformer Without Dead-zone Based on the Double Winding Coupling of the Primary Side

该文提出一种适用于电动汽车无线充电系统的新型原边双绕组耦合直流变压器(DC transformer,DCT),在不增加额外电感的前提下,从拓扑上消除了桥臂直通问题,无需加入死区,提高了直流电压利用率。此外,功率管能够实现零电流开通,并通过变压器并联效应减小漏感的影响,提高变压器传输效率。文中给出能够实现自动功率匹配的三级式无线充电系统结构,讨论DCT在系统中的作用与优势,详细分析所提出的DCT拓扑与工作原理,提出多线圈耦合电路的等效方法,最后通过与全桥DCT的仿真和实验结果对比,验证理论分析的正确性和所提出DCT的先进性。

This paper proposed a novel DC Transformer （DCT） based on the double winding coupling of the primary side, which applies to the wireless charging system of the electric vehicle. The straight-through problem can be eliminated from the topology on the premise of no additional inductance. The dead-time is not needed and the DC voltage utilization. What＇s more, the power switches can realize zero-current turn-on. The influence of the leakage inductance can be decreased by the parallel effect. As a result, the transmission efficiency of the DCT can be improved. In this paper, the three-stage structure of the wireless charging system was given. It can realize automatic power matching. The functions and advantages of the DCT were discussed. The topology and working principle of the proposed DCT was analyzed： The equivalent method if the multiple coils coupling circuit was proposed. Finally the simulation and experimental comparison of the full-bridge DCT and the proposed DCT were given. The results can verify the correctness of the theoretical analysis and the advancement of the proposed DCT.