【作者】 朱星光；

【导师】 陈唐龙；

【作者基本信息】 西南交通大学 ， 电气工程， 2013， 硕士

【摘要】 从宇宙诞生、地球形成到人类的出现、进化、发展,能源—直扮演着极其重要的角色。随着社会经济的不断进步,严峻的环境问题越来越成为摆在人们面前的一个亟待解决的重要议题。世界各国都已经并且持续投入大量的资源对清洁、绿色能源进行学术研究和产品开发。作为氢能领域代表的质子交换膜燃料电池(Proton Exchange Membrane Fuel Cell, PEMFC)技术以其低排放、高效率、结构简单等优势尤其受到青睐。但PEMFC也因其内部电化学反应的高度非线性过程而存在着强耦合性、大滞后性、约束性、不确定性和随机干扰等特点,具体表现为受外界环境和操作条件因素影响大、输出电压不稳定、输出特性较软、响应速度慢、需要对外进行排水操作(Purge)、易发生氢气泄露等不足之处。因此对其商业化前景和应用推广造成了较大阻碍,需要探索和研究其特性,基于此设计并选择更合适的控制策略,扬长避短,最终开发研制出适合商业化推广的产品,真正为人类社会发展服务。本文通过对PEMFC所做的单体电池电压分布和不同风扇系统的流速与功耗平衡分析实验,得出通过单体PEMFC电压分布可以检验和判断电堆是否符合设计要求,并在运行过程中对其进行实时监测、定位性能欠佳的单体电池以进行控制策略上的调整的结论,提出流过燃料电池阴极的空气流速和风扇系统功耗之间存在着一个平衡的观点。设计了一种外部控制策略,使PEMFC系统摆脱了对外排水(Purge)的束缚。为了全面、完整的掌握阴极风扇系统对PEMFC的影响,通过大量针对风扇系统的实验,得出当风扇工作在“吸”模式下,电池的表面工作温度分布和空气流量分布更均匀且性能史好,电池表面工作温度分布与流过电池阴极的空气流量分布具有一致性的观点。设计了一种在外接负载变化时针对阴极风扇系统的控制策略,达到仅需对阴极风扇进行调节便可在不同负载条件下实现对外输出性能最优的口标。设计建立PEMFC动态多输入多输出模型并在Matlab/Simulink软件环境下进行仿真,证实该系统可以模拟燃料电池的瞬态响应性能并保证电池外接负载发生较大变化时两极气体压力差尽可能小,对质子交换膜形成有效的保护,达到延长电池使用寿命的目标。基于前述研究中提出的儿种新型控制策略,设计制造了一款PEMFC便携式电源,制作了硬件控制电路板并编写了控制程序,实现对PEMFC系统的优化控制,对便携式电源实物展开实际测试证实其可用性良好。设计的PEMFC测试平台系统,运行良好且能够完成各种测试任务,证明两种产品均具有广阔的商业前景和实际应用价值。更多还原

【Abstract】 From the birth of the universe, the formation of the Earth to the emergence of human evolution, development, energy has been playing a very important role. As social and economic progress, the serious environmental problems has increasingly become an urgent need to solve the important issues before the people. Countries in the world have been and continue to invest a lot of resources for academic research and product development for clean, green energy. Represented as hydrogen energy proton exchange membrane fuel cell technology with its low-emission, high efficiency, simple structure and other advantages are particularly favored. But because of its highly non-linear process of internal electrochemical reaction there is a strong coupling, large lag, constraints, uncertainty and random interference characteristics, specific performance is affected by the external environment and operating conditions factors, unstable output voltage, softer output characteristics, slow response, purge operation, prone to hydrogen leaks and other inadequacies. Therefore hinder its prospects for commercialization and application promotion need to explore and study its characteristics, design and choose a more appropriate control strategy based on this advantage, eventually developed to promote the commercialization of products for the development of human society services.Based on an open-cathode and self-humidifying design proton exchange membrane fuel cell stack prototype and other related equipment, the voltage distribution of each cell as well as the air velocity and flow rate, was measured under with-load and without-load conditions. The single cell voltage distribution analysis could monitor whether stack performance match the design requirement, it also could locate the position of low performance single cell and thus the weakest link can be improved. There was a comprise between the air velocity through the cathode and fan system power. An external control strategy is designed to make the PEMFC system to get rid of the purge operation.In order to complete and comprehensive grasp the cathode fan system influences on PEMFC, through a large number of experiments for the fan system. It is observed that cathode fan system has a different operating mode and air flow velocity distribution. When the fan system operating mode in cathode is "Suction", its temperature distribution more uniform than mode is "Blow", and it has better performance. It have consistency principle that between the fuel cell surface temperature distribution and air flow distribution through the cathode. Designed for an external load changes the cathode fan system control strategy, reaching only external output optimal performance goals can be achieved under different load conditions to adjust the cathode fan.Established a dynamic multi-input multi-output (MIMO) model of PEMFC and non linear control. A design of a relevant controller, is needed as the huge gases pressure difference between anode and cathode gases will lead to fuel cells’serious membrane damages. The design can minimize the damages and extend the lifetime of the PEMFC as long as possible. After establishing and combining the PEM fuel cell model and nonlinear controller design, it turns out the whole system is able to imitate the transient performance of fuel cells and protect the fuel cell membrane as well under the environment of Matlab/Simulink.Several new control strategy based on the aforementioned study, design and manufacture of a PEMFC portable power pack, making the hardware control circuit board and the preparation of the control program, PEMFC system optimization control, through the actual start of the portable power pack physical test to confirm its availability. Design the PEMFC test station system, running well and is able to complete a variety of test tasks to prove that the two products have a broad business outlook and practical value.更多还原