【作者】 刘鹏；

【导师】 陈启宏；

【作者基本信息】 武汉理工大学 ， 控制科学与工程， 2021， 硕士

【摘要】 节能与环保是当前国际汽车领域亟待解决的两大问题,大力发展新能源汽车是重要的方案之一。燃料电池汽车具有清洁环保、节能高效等显著优点,是新能源汽车领域的一个重要发展方向。燃料电池用DC/DC变换器是车用燃料电池系统中的一个核心部件,它承担变换电压等级与输出匹配、调节燃料电池功率等作用,是该领域的一个研究热点。本文以提高燃料电池用升压DC/DC变换器的动态响应能力、降低燃料电池输出电流纹波为主要目标,开展燃料电池用升压DC/DC变换器预测控制研究与实现,主要内容如下:设计了升压DC/DC变换器总体方案。分析了燃料电池输出特性,在此基础上进行了DC/DC变换器需求分析,设计了DC/DC变换器六相交错并联拓扑结构,并对其工作机理及纹波电流进行了分析,对电路中的主要参数进行了计算和器件选型。最后进行仿真研究,验证了设计方案的有效性。建立了DC/DC变换器模型。在分析DC/DC变换器工作模态的基础上,对六相交错并联DC/DC变换器进行了解耦,采用小信号分析法建立了DC/DC变换器的状态空间模型,并得到每相电感电流和占空比的传递函数。然后根据DC/DC变换器状态方程和电路的特性,推导出DC/DC变换器的状态预测方程。设计了基于输入电流控制的DC/DC变换器预测控制器。根据DC/DC变换器输入电流控制需求,定义了相应的控制价值函数和约束,设计了DC/DC变换器模型预测控制策略,并通过递归神经网络求解控制量,将带约束的二次优化问题转化为一次求解问题,大幅降低了计算量。最后通过仿真实验,验证了其动态性能和稳态性能。设计并实现DC/DC变换器的模型预测控制器。设计了基于DSP+FPGA双CPU的DC/DC变换器控制器软硬件。硬件设计包括DSP最小系统设计、采样电路设计、控制电路设计等;软件实现了基于FPGA的DC/DC变换器预模型控制算法。最后基于设计的DC/DC变换器功率电路和控制器,构建了实验平台,对本文提出的方法进行了实验验证。实验结果表明本文设计的基于输入电流控制交错并联DC/DC变换器能有效控制输入电流纹波,提升系统动态性能。更多还原

【Abstract】 Energy saving and environmental protection are two major problems in the international automotive field.It is one of the important solutions to develop new energy vehicles.Fuel cell vehicle has the advantages of clean and environmental protection,energy saving and high efficiency,it is an important development direction in the field of new energy vehicles.DC/DC converter for fuel cell is a core component of vehicle fuel cell system.It is a hot research field,which plays the role of voltage transformation and matching,regulating fuel cell power and so on.In this thesis,the main objectives are to improve the dynamic response capacity of boost DC/DC converter for fuel cell and reduce the current ripple of fuel cell output.The main contents are as follows:The overall scheme of boost DC/DC converter is designed.The output characteristics of fuel cell are analyzed.Based on the analysis of DC/DC converter demand,the six intersecting and parallel topology of DC/DC converter is designed.The working mechanism and ripple current are analyzed.The main parameters of the circuit are calculated and the device selection is selected.Finally,the simulation study is carried out to verify the effectiveness of the design scheme.The DC/DC converter model is established.Based on the analysis of the working mode of DC/DC converter,the six-phase interleaved parallel DC/DC converter is decoupled.The state space model of DC/DC converter is established by using small signal analysis method,and the transfer function of inductance current and duty cycle of each phase is obtained.Then,according to the state equation and the characteristics of the circuit,the state prediction equation of DC/DC converter is derived.The predictive controller of DC/DC converter based on input current control is designed.According to the input current control of DC/DC converter,the corresponding control value function and constraints are defined.The predictive control strategy of DC/DC converter model is designed.The control quantity is solved by recursive neural network,and the constrained secondary optimization problem is transformed into primary solution problem,which greatly reduces the calculation amount.Finally,the dynamic and steady-state performance of the system are verified by simulation experiments.The model predictive controller of DC/DC converter is designed and implemented.The hardware and software of DC/DC converter controller based on DSP and FPGA Dual CPU are designed.The hardware design includes the design of DSP minimum system,sampling circuit and control circuit,etc.the software design realizes the predictive model control algorithm of DC/DC converter based on FPGA.Finally,based on the designed DC/DC converter power circuit and controller,the experimental platform is built,and the method proposed in this paper is verified.The experimental results show that the interleaved parallel DC/DC converter based on input current control can effectively control the input current ripple and improve the dynamic performance of the system.更多还原