基于电流调节的燃料电池发动机过氧比波动研究

Research on the Oxygen Excess Ratio Fluctuation with Current Regulation for a PEM Fuel Cell Engine

当前质子交换膜燃料电池发动机(系统)的空气端控制主要采用前馈/反馈控制结构,这一控制策略会在电流急剧变化时导致过氧比的剧烈波动,从而影响燃料电池的"健康状况".针对这一问题,提出了对电流进行调节以缓解过氧比波动.通过给定的电流工况,研究了电堆拉取电流调节最优的一阶动态环节时间常数.仿真结果表明,该时间常数的选择取决于动、静态2大因素的选取.动态因素为电流的变化幅值和初始值,静态因素为空压机的转动惯量及在车内的安装位置(或进气歧管体积).

Currently the control of air flow in PEMFC system is mainly feed forward/feedback configura tion which will inevitably lead to the ratio fluctuation when the current changes abruptly. The ratio fluctu ation can affect the health of fuel cells. This research aims to find the optimal time constant of first-order dynamics for the drawn current from the stack. The simulation results indicate that the time constant de pends on not only the change in the magnitude of request current and its initial value, but also the com- pressor inertia and its location in the vehicle.