摘要
为了减小双有源全桥DC-DC变换器的电流应力,提高变换器的效率,同时显著增强变换器的动态性能,本文在双重相移控制的基础上提出一种基于模型前馈的电流应力优化方法。该方法通过建立变换器输出电压的离散模型并引入前馈控制,同时结合电流应力优化计算,可以实现变换器效率优化并显著地提高其对于负载突变和输入电压突变的响应能力。同时,该方法可以有效地改善变换器的起动特性,使得输出电压在无明显超调的情况下直接达到给定电压值。最后,搭建了以TMS320F28335为核心控制器的基于SiC MOSFET的双有源全桥DC-DC变换器小功率实验样机,以传统的单重相移电压闭环控制方法和双重相移电流应力优化控制为参考,对所提出的基于模型前馈的电流应力优化方法进行对比实验,实验结果验证了所提控制方法的正确性与有效性。
In order to reduce the current stress, improve the efficiency and enhance the dynamic response of dual-active-bridge(DAB) DC-DC converters, a current stress optimized scheme with model-based feedforward is proposed in this paper. Through developing the discrete model of output voltage, introducing feedforward control and combining the current stress optimized calculation, the efficiency and dynamic performance of DAB converters under the input voltage fluctuation and load disturbance conditions can be improved significantly. In addition, the proposed control scheme can effectively improve the starting characteristics of the converter, so that the output voltage reaches the desired value directly without overshoot. Finally, three control schemes, i.e. traditional voltage-closed control based on single phase-shift, current stress optimized control based on dual phase-shift and the proposed current stress optimized scheme with model-based feedforward, are compared in a DAB converter scale-down experimental prototype based on SiC MOSFET with TMS320F28335 as the core controller. The experimental results have verified the correctness and effectiveness of the proposed control scheme.
引文
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