Efficiency Optimization Control of The Proton Exchange Membrane Fuel Cell System Under Variable Altitude Condition

In order to solve the problem of inefficient operation of Proton Exchange Membrane Fuel Cell (PEMFC) caused by low pressure and low oxygen environment at high altitudes, an efficiency optimization control method (EOCM) for PEMFC system based on variable altitude optimal oxygen excess ratio (OER) was proposed. By testing the optimal efficiency characteristics of PEMFC system models in various high-altitude environments on the RT-LAB semi-physical platform, the optimal OER trajectory under variable altitude environment was obtained to realize the high efficiency region division of PEMFC system. Based on the results of high-efficiency regional division, the sliding mode control based on super-twisting algorithm was adopted to realize the optimal control of PEMFC system. Test verification was carried out on the RT-LAB semi-physical platform, and the results showed that the EOCM method proposed in this paper can keep the high efficiency operation of PEMFC system under the condition of variable altitude. In addition, under different working conditions, EOCM method can still improve the efficiency of PEMFC system, quickly track the optimal peroxide ratio, reduce the overshoot and dynamic response time, and achieve good control effect to ensure the efficient operation of PEMFC system.