Study On Optimization Of PEMFC Air System Of Locomotive

With environmental pollution and energy shortage intensified,fuel cell technology,especially the proton exchange membrane fuel cell(PEMFC)as a promising new energy technology,has wide application prospect in distributed power station,electric vehicle power system,new energy power train system etc.In a heavy power fuel cell power system,air supply system is one of the most important auxiliary equipment,according to the needs of power system operating conditions,providing sufficient pressure and flow of air in real-time to meet the needs of internal electrochemical cell reaction accurately and quickly.Because the time scale of the current change is microsecond level,and the time scale of the gas flow changes is second level,the load capacity of the fuel cell system is limited by the dynamic response of the gas supply system.Research on the control method of fuel cell air supply system is the key to enhance the response speed of the air compressor,quickly and accurately meet the fuel cells required for air flow for large power fuel cell engine system.Therefore,this paper introduces the working principle of proton exchange membrane fuel cell and centrifugal air compressor and built locomotive simulation experimental platform with the 150kW proton exchange membrane fuel cell air system,based on the model and control strategy of centrifugal compressor in the domestic and foreign research results,and the design of the whole modeling and control method for the air supply system of proton exchange membrane fuel cell,provide the basis for the ROTREX C15-16 series centrifugal compressor performance test and optimization control validation.A semi empirical model was established for ROTREX C15-16 series air compressor,and a air supply system was built for heavy power PEMFC model including centrifugal air compressor.According to the simulation result and the actual working performance of PEMFC dynamic response requirement,proposing a PEMFC actual current following PID control method,realizing the quick response of the centrifugal air compressor in the course of PEMFC variable load,the performance superiority of the centrifugal air compressor is fully brought into play,the purpose of the air flow is satisfied,and the hysteresis characteristic of the prior control mode is improved.The results of simulation and experiment show that the PEMFC actual current following PID control method can adjust the speed of the air compressor and the air flow of the air supply system more effectively and quickly to ensure the stable and efficient operation of the system.Finally,the phenomenon and principle of the "surge" in the operation of the centrifugal compressor at low speed and the influence on PEMFC are introduced,and using the binary anti surge valve to optimize the phenomenon of "surge".The effect of the binary anti surge valve is verified by experiments,and a method to quantitatively select the grade of the relief valve is presented.In this paper,the design of the control method and anti surge method for the actual control system design has important guiding significance.