一种双有源桥变换器单侧非对称占空比调制策略

One-sided Asymmetric Duty Modulation Strategy for Dual Active Bridge Converter

针对双有源桥变换器在单移相调制策略中宽电压范围情况下的低效率问题,文中提出了一种单侧非对称占空比调制策略,显著的提升了双有源桥变换器的效率,尤其是在轻载情况下。首先描述了单侧非对称占空比调制方式的原理,并根据控制自由度的关系得到了两种工作模式。第二,基于时域分析,推导了两种工作模式的稳态特性,包括电感电流以及传输功率。第三,为了寻求控制自由度的最优组合,选择电感电流峰峰值作为优化目标,应用KKT条件得到了最优的单侧非对称占空比调制策略。最后,搭建了一台基于碳化硅器件的双有源桥变换器实验平台,实验验证了单侧非对称占空比调制策略的有效性。

Aimed at the problem of low efficiency of a dual active bridge(DAB)converter in the wide voltage range of single phase shift modulation strategy,a one-sided asymmetric duty modulation strategy is proposed in this paper,which significantly improves the efficiency of DAB converter,especially in the case of light load.First,the principle of one-sided asymmetric duty modulation scheme is described,and two operation modes are obtained according to the relationship of control degrees of freedom.Second,based on the time-domain analysis,the steady-state characteristics in the two operation modes are derived,including inductance current and transmission power.Third,in order to find the optimal combination of control degrees of freedom,the peak-to-peak value of inductance current is selected as the optimization objective,and the optimal one-sided asymmetric duty modulation strategy is obtained by applying the KKT condition.Finally,an experimental platform for DAB converter based on SiC device was built,and experimental results verified the effectiveness of the proposed one-sided asymmetric duty modulation strategy.