双有源全桥变换器全状态离散迭代建模与输出电压纹波分析

Full-State Discrete-Time Model and the Output-Voltage-Ripple Analysis of the Dual Active Bridge Converter

针对双有源全桥(DAB)DC-DC变换器传统离散迭代模型的缺陷和不足,该文提出DAB变换器的全状态离散迭代模型,并基于此对不同参数和工况条件下的输出电压纹波进行分析。目前,国际上广泛采用的DAB变换器离散迭代模型是基于一个开关周期内不同子区间逐个迭代的,经过分析可以发现,传统离散迭代模型会遗漏状态变量的许多关键信息,并不能反映出变量的真实状态。通过深入分析DAB变换器的工作原理,提出的全状态离散迭代模型则包含了变换器在一个开关周期内所有关键时刻的状态变量信息。以输出电压为例,全状态离散迭代模型可以反映出工作子区间切换时刻的输出电压信息,因而其输出电压纹波分析结果更加真实,在此基础上的参数优化设计更有利于抑制输出电压纹波和提高系统可靠性。最后,通过仿真和搭建的实验平台验证了模型和理论分析结果的正确性。

By analyzing the drawbacks of the conventional discrete-time model of the dual active bridge(DAB)converter,the full-state discrete-time model of the DAB converter is proposed,and the output-voltage-ripple analysis under different system parameters and working condition is conducted.The conventional discrete-time model of the DAB converter is based on the interval-by-interval iteration,which will miss many essential information of the state variables and cannot reflect the actual working condition of the converter.By analyzing the working principle of the converter,the proposed full-state discrete-time model can reveal all the crucial information of the state variables.Taking the output voltage as an example,the full-state discrete-time model can reveal the output-voltage information at the subinterval switching moment.Therefore,the output-voltage-ripple analysis is more accurate and conducive to improving system reliability.The experimental results also verify the proposed model and the analysis results.