基于最大净功率输出的PEMFC阴极供气系统优化控制研究

STUDY ON OPTIMAL CONTROL OF CATHODE GAS SUPPLY SYSTEM OF PEMFC BASED ON MAXIMUM NET POWER OUTPUT

通过建立质子交换膜燃料电池(PEMFC)阴极供气系统数学模型,分析空气压缩机电压和背压阀开度对系统净功率输出的影响;针对负载电流变化,研究PEMFC系统对应的最优过氧比和最优阴极压力,建立最大输出净功率-过氧比-阴极压力寻优表;考虑过氧比和阴极压力之间的耦合关系,基于辨识出的传递函数矩阵,设计针对空气压缩机电压和背压阀开度的前馈解耦控制器,优化氧气供给和压力控制,并进行相应的仿真验证。结果表明,所提解耦控制器能有效减小过氧比和阴极压力之间的耦合影响,在实现最大净功率闭环控制的同时,具有更快的响应速度和更小的超调量。

By establishing the mathematical model of the gas supply system of cathode gas supply system of proton exchange membrane fuel cells(PEMFC)cathode,this paper analyzed the influence of the voltage of air compressor and the opening of back pressure valve on the net power output of the system.According to the change of load power,the oxygen excess ratio and cathode pressure corresponding to PEMFC system were studied,and the optimization table of maximum output net power-oxygen excess ratio-cathode pressure was established.Considering the coupling relationship between the oxygen excess ratio and the cathode pressure,based on the identified transfer function matrix,a feedforward decoupling controller was designed for the voltage of the air compressor and the opening of the back pressure valve to optimize the oxygen supply and pressure control.The simulation results show that the proposed decoupling controller can effectively reduce the influence of coupling,achieve the maximum net power closed-loop control,and has faster response speed and smaller overshoot.