安全操控下5 kW固体氧化物燃料电池电堆预测控制器设计

基于5 kW固体氧化物燃料电池(SOFC)电堆,考虑建模仿真—2温度层模型在模型精度与复杂度上做了更好的折中,可以更有效地应用于控制器设计.本文首先对2温度层模型在常用稳态工作点附近采用泰勒级数展开,获得其状态空间方程.然后考虑其安全操作特性,设计了两种带约束的预测控制器:即面向SOFC电堆的快速负载跟踪与燃料亏空控制器与面向SOFC电堆温度安全的控制器.重点分析了不同切换速率工况下的温度及其梯度、功率以及燃料亏空特性,使得系统在快速进行功率跟踪的同时工作在安全范围以内.结果发现随着电流调节速率的增大,跟踪过程虽然加快,但其存在安全风险也相应增大;此外,安全指标相对避免燃料亏空指标而言,对电流调节速率的要求更加苛刻,在控制器设计时必须综合进行考虑.

The constrained predictive controller design based on safe operating of a 5 kW solid oxide fuel cell stack

Based on the 5 kW solid oxide fuel cell (SOFC) stack, considering its stack modeling and simulation with two temperature layers can not only dramatically reduce the modeling complexity, but also shows higher precision, which should be preferred in controller design. In the light of the above thinking, this paper firstly obtain the state-space equations by the applications of the Taylor series extension theory to the common static working points. Then, considering the safe operating, two constrained predictive controllers are designed, namely the fast load tracking and fuel exhaustion avoidance oriented controller and the thermal safety oriented controller. Especially, the temperature and its gradient, output power, and fuel exhaustion are emphatically analyzed under different current regulation rate in this paper, which can ensure fast power tracking and safe operating simultaneously. The result shows that although power tracking process accelerated with the increase of the current regulation rate, the risk coefficient of operating safety is increasing too. Moreover, control standards of fuel exhaustion shows more rigorous compared to operating safety, which should comprehensively consider during controller design.