双向全桥DC-DC变换器基于电感电流应力的双重移相优化控制

摘要

Through the analysis of the isolated bidirectional dual-active-bridge dc-dc converter (IBDC) with single-phase-shifting (SPS) control and dual-phase-shifting (DPS) control, the mathematical relationships among the inductor current stress, the output power, the input/output voltage conversion ratio and the phase-shift angle ratios were deduced in this paper. In order to effectively reduce the converter current stress, the phase-shift angle ratios were optimized to minimize the inductor current stress in different output power and voltage conversion ratios. Accordingly, an optimal DPS control strategy for IBDC is proposed, which can minimize the current stress of the converter while achieving the closed-loop control of output voltage. Hence, the IBDC current stress of DPS control is always smaller than that of SPS control. Moreover, the proposed strategy shows its superiority when the converter works in light load and the voltage conversion ratio is relatively large. Compared with SPS control, the proposed strategy is verified through a built prototype.%通过分析双向全桥 DC-DC 变换器采用单移相和双重移相控制的工作原理，推导出了两种控制方式下变换器电感电流应力与传输功率、输入与输出电压调节比及移相角比之间的数学关系。为了有效降低变换器电流应力，针对不同的传输功率及电压调节比，通过寻优求得使电感电流应力达到最小的最优移相角。据此提出一种双向全桥DC-DC变换器双重移相优化控制策略，在实现输出电压闭环控制的同时使变换器电流应力达到最小。采用该优化控制策略，双重移相控制的电流应力始终小于单移相控制，并且当变换器工作在轻载且电压调节比较大时，该优化控制策略的优势更加突出。搭建了实验样机，对理论分析进行了验证，并与传统单移相控制进行了对比。实验结果验证了所提出最优控制策略的有效性与可行性。