Study On Control Stratgy Of Proton Exchange Membrane Fuel Cell

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.