基于三重移相控制的双有源桥变换器研究

Research on Dual Active Bridge Converter Based on Triple Phase Shift Control

为了加快“碳中和”及“碳达峰”的进程,可再生能源逐渐取代了化石能源,成为了未来主要的发电方式。储能系统与双向变换器的组合成为了维持微网电压稳定、削峰填谷的核心组件。针对这一背景,对具有较强双向调节能力的双有源桥变换器展开研究。采用三重移相控制,详细分析了变换器在特定工作模式下的工作过程。此工作模式适用于轻载条件,具有双向能量传输的能力。建立了相应的电流应力、传输功率和软开关特性的数学模型。基于电流应力的变化情况,提出了一种基于三重移相控制的电流应力优化策略。以电流应力为目标函数,以软开关范围和模式边界为限制条件,求解得到了最优移相比组合。该优化控制策略可以在保证软开关运行条件下减小变换器的电流应力,提高变换器的性能。最后通过实验测试验证了理论分析的正确性。

In order to speed up the process of "carbon neutrality" and "peak carbon dioxide emissions",fossil energy has been gradually replaced by renewable energy,and renewable energy will become the main power generation mode in the future. The combination of energy storage system and bidirectional converter become the core component to maintain the voltage stability of microgrid,and realize peak shaving and valley filling. In view of this background,the dual active bridge(DAB)converter with strong energy bidirectional regulation capability was studied. The working process of the DAB converter in a specific working mode was analyzed in detail by using triple phase shift control. This working mode is suitable for light load conditions and has the capability of bidirectional energy transmission. The corresponding mathematical models of current stress,a current stress optimization strategy which is based on triple phase shift control was proposed. The current stress was taken as the optimization objective,and the soft switching range and mode boundary were taken as the constraints,and the optimal phase shift combination was obtained. The optimal control strategy can reduce the current stress of the converter and improve the performance of the converter under the condition of ensuring the soft-switching operation. Finally,the correctness of the theoretical analysis was verified by experimental tests.