Dynamic Simulation and Control Strategy Development for Safe and Fast Start-up on Solid Oxide Fuel Cell

An elevated temperature is required for solid oxide fuel cell (SOFC) which operates at high temperature (approximate 800 degrees C). This paper addresses the dynamic characteristics of solid oxide fuel cell with an emphasis on control strategy development for optimized process of start-up. A methodology on regulating inlet flow rate, temperature and current rate is investigated to make sure the increment rate of stact temperature is allowed for safe and fast start-up. An integrated dynamic model for a planar solid oxide fuel cell composed of mass balance, temperature dynamics and electrochemical reaction works together with fuzzy sliding mode controller in MATLAB/Simulink to simulate the dynamic characteristic of start-up process in the paper. Two strategies based on fixed and variable inlet temperature difference respectively are proposed and disscused. Simulation results show the variable inlet temperature difference strategy can reduce the duration for safe start-up compared with the fixed inlet temperature difference strategy.