基于SiC器件的交错并联双向DC-DC变换器的设计

Design of interleaving bidirectional DC-DC converter based on SiC components

针对传统组串式储能变流器存在的系统损耗大、输出电能质量低及整体可靠性差等问题,文中提出一种新型两相交错并联变换器拓扑,以提高系统效率及过流能力。首先给出交错并联DC-DC变换器的拓扑结构,分析两相交错并联拓扑结构工作原理,并推导相应的小信号模型,求其开环传递函数;然后以提升系统响应速度为目标,设计基于电流内环、电压外环的串级控制器,搭建基于SiC器件的10 kW样机。通过大电流实验、双脉冲实验对样机进行稳定性验证,最后对样机充放电模式分别进行效率测试。实验结果表明,基于SiC器件的两相交错并联双向DC-DC变换器能在一定程度上减小电流纹波,提高变换器功率等级,显著提升效率。

In allusion to the problem of large system loss,low output power quality and poor overall reliability of traditional series energy storage converter,a novel two-phase interleaving converter topology is proposed to improve the system efficiency and overcurrent capacity. The topology structure of interleaving DC-DC converter is provided,the working principle of two-phase interleaving topological structure is analyzed,and the corresponding small signal model is deduced,and the open-loop transfer function is resolved. Taking the enhance system response speed as the goal,the cascade controller based on the inner-loop current and outer-loop voltage is designed,the 10 kW prototype based on SiC device is constructed. The stability of the prototype is verified by the large-current experiment and double-pulse experiment. The efficiency test of the charging-discharging modes of the prototype was conducted. The experimental results show that the two-phase interleaving bidirectional DC-DC converter based on SiC device can reduce the current ripple to a certain extent,and improve the power level of the converter and the converter efficiency.