Research On Temperature Control Strategy Of Fuel Cell Test System

Proton Exchange Membrane Fuel Cell(PEMFC)is an important branch in the field of new energy.In addition to the advantages that fuel cells has such as zero pollution,high efficiency and low noise,it also has the advantages of low temperature,high power density and rapid start-up.However,the operating temperature of PEMFC has a significant impact on its output performance,service life and efficiency.The fuel cell test system is an indispensable equipment for the characterization of fuel cell core modules and components,stack design and iterative optimization,and fuel cell product performance testing and evaluation,and it plays a huge role in promoting the development of fuel cells.Temperature is an important factor affecting the performance of fuel cells.However,the fuel cell system itself has the characteristics of coupling,hysteresis and time-varying,and the control effect of the traditional control strategy is not ideal.In addition,due to the uncertainty of the measured object of the fuel cell test platform,the heat generated by the stack will vary greatly with the rated power,performance and actual operating current point of the stack,which makes it difficult to accurately control the temperature in practical applications.Therefore,it is of great significance to study the temperature control strategy of the proton exchange membrane fuel cell test system.The research contents of this thesis are as follows:1.This thesis introduced the working principle of fuel cell,and summarized the structure and functional characteristics of the fuel cell test system.Then it introduced the research status at home and abroad based on the model of the thermal management module and the temperature control algorithm of the fuel cell test system.2.This thesis analyzed the heat generation and heat dissipation during fuel cell operation,designs the hardware structure of the heat management module of the fuel cell test system,and selected the key equipment of the heat management module.Thereafter the software control module of the fuel cell test system was developed,and the friendly man-machine interface was designed to meet the requirements of fuel cell test.3.In order to control the temperature of fuel cell accurately,a thermal model of fuel cell stack was established based on the working principle and thermal balance equation of PEMFC.Then the mathematical models of the circulating water pump,the circulating water tank and the radiator in the thermal management module of the fuel cell test system were established.Finally,an integrated closed-loop thermal management system model was established.4.Based on the simulation model of the heat management module,a suitable temperature control strategy was designed to control the switch time of the radiator fan and the rotation speed of the water pump in the heat management module.The temperature control strategy was implemented in the actual fuel cell test system,and the simulation results were verified.The results show that the thermal management module and temperature control strategy designed in this thesis can keep PEMFC working at a stable temperature under steady or dynamic operating conditions.