负载电流前馈闭环控制的快速动态响应双有源桥式变换器的输出阻抗分析  

Output Impedance Analysis of Dual Active Bridge Converter with Load Current Feedforward Closed-loop Control for Fast Dynamic Response

作　　者：李沫霖 郭志强[1] LI Molin;GUO Zhiqiang(School of Automation,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学自动化学院,北京100081

出　　处：《电源学报》2020年第3期55-62,共8页Journal of Power Supply

基　　金：国家自然科学基金资助项目(51807007)。

摘　　要：提出了一种基于前馈控制的双有源桥DAB(dual active bridge)变换器的控制策略,并通过小信号模型分析了DAB变换器的输出阻抗及其对电路动态特性的影响。DAB变换器的输出阻抗不仅取决于输出电容,还与控制回路的增益有关。由于传输延迟和零阶保持器的存在,控制回路的交叉频率和增益不能选得过高。如果输出电容非常低,变换器无法实现快速动态响应。为了提高动态性能,根据期望的输出电流,提出了一种新的前馈控制策略。前馈路径只与负载电流有关,而对于输出电压是独立的,且前馈控制在实时计算中易于实现。这种具有前馈控制策略的闭环增益与单电压闭环控制的比较结果表明,采用前馈控制的控制回路具有较好的动态性能。最后,搭建了1 kW的实验样机,验证了所提控制策略的有效性。In this paper,a control strategy of dual active bridge(DAB)converter based on feedforward control is pro-posed.By analyzing a small-signal model,the output impedance from the DAB converter is analyzed.The output impedance,which is associated not only with the output capacitor but also with the gain of the control loop,has an impact on the circuit’s dynamic performance.Due to the transport delay and zero-order holder(ZOH),the crossover frequency and gain of the control loop cannot be selected to be too high.If the output capacitance is very low,then the converter cannot achieve fast dynamic response.To improve the dynamic performance,a novel feedforward control strategy is proposed according to the desired output current.The feedforward path is only associated with load current,and it is independent of the output voltage.Furthermore,the feedforward control is easy to implement in the real-time calculation.The closed-loop gain under the control strategy with feedforward is compared with that under single voltage closed-loop control,demo-nstrating that the control loop with the proposed feedforward control has better dynamic performance.Finally,a 1 kW experimental prototype was built,and experimental results verified the effectiveness of the proposed control strategy.

关 键 词：DAB 前馈 快速动态响应 

分 类 号：TM46[电气工程—电器]