多模块双有源全桥变换器的模型预测控制

MPC of multi⁃module dual active full⁃bridge converters

文中以级联型电力电子变压器(PET)中输出并联的双有源桥(DAB)变换器为研究对象,对多模块并联DAB拓扑结构进行建模,利用模型预测控制(MPC)实现各模块的功率均衡控制。在此基础上,针对实际级联型PET设备的DAB模块无负载电流传感器的情况,提出一种改进的模型预测控制策略。该策略利用DAB的功率传输特性计算得到总输出电流,通过电流均分实现在只对输出电压进行采样的情况下各模块的等功率运行,无需额外引入虚拟电流来代替采样电流。最后,通过Matlab/Simulink仿真和搭建以TMS320F28335为核心的两个模块DAB并联输出实验样机,验证所提出的控制策略。实验所得结果与理论分析一致,且与传统的控制策略相比,该控制策略动态响应更快,输出纹波更小,模块化的控制便于实现大规模的级联,能够有效降低成本。

The dual active bridge(DAB)converter with parallel output in the cascaded power electronic transformer(PET)is taken as the research object,the modeling of multi⁃module parallel DAB topology structure is conducted,and the power balance control of each module is realized by means of the model predictive control(MPC).On this basis,an improved MPC strategy is proposed for the case that the DAB module of the actual cascade PET equipment has no load current sensor.The strategy can be used to calculate the total output current by means of the power transmission characteristics of the DAB,the current equalization is used to realize the equal power operation of each module under the conditions that only the output voltage is sampled,but does not need to introduce any additional virtual current to replace the sampling current.The proposed control strategy is verified by means of the Matlab/Simulink simulation and the construction of two⁃module DAB parallel output experimental prototype taking TMS320F28335 as the core.The experimental results are consistent with the theoretical analysis.In comparison with the traditional control strategy,the dynamic response of the control strategy is faster,its output ripple is smaller,and its modular control is easy to achieve large⁃scale cascade,which can effectively reduce costs.