一种混合型输入串联输出并联直流变压器

An ISOP Hybrid DC Transformer

现有基于多变换器输入串联输出并联(input-series output-parallel,ISOP)结构的直流变压器子模块大多采用单一模块,在实现灵活控制和高效率之间很难达到平衡。基于模块化技术,提出了一种基于CLLLC谐振变换器子模块和DAB变换器子模块的混合型ISOP结构直流变压器拓扑,分别利用CLLLC谐振变换器的高效率与DAB变换器的高可控性优点,通过2类子模块数量和高频变压器变比的合理设计,CLLLC谐振变换器将传输绝大部分功率,从而提高整个直流变压器的效率。详细分析了该混合型ISOP直流变压器的工作原理与设计方法,并利用PLECS软件验证了所提出的直流变压器拓扑的可行性,最后通过一台2k W,400V/100V的样机进行实验验证。

Most of the existing sub-modules based on modular DC transformers use a single module.It is difficult to achieve a balance between flexible control and high efficiency,which limits its practical application.Based on the modular technology,a hybrid DC transformer(HDCT)combining multiple CLLLC converters and dual-active bridge(DAB)converters with input-series-output-parallel(ISOP)configuration is proposed in this paper.Through reasonable design of the number of sub-modules and high-frequency transformer ratio,CLLLC converters transmit most of the power,which improves the efficiency of the entire DC transformer.The operation principles of the proposed HDCT are analyzed and the key design parameters are presented.Then a 500 kW,10 kV/750 V HDCT is simulated and a HDCT prototype with 2 kW,400 V/100 V is built to verify the theoretical analysis.