H-infinity controller for solid oxide fuel cells

The objective of this paper is to regulate output fuel cell voltage for small load variations by changing input fuel flow, and to protect fuel cell stack by controlling fuel utilization parameter. Fuel cell utilization, which is dependent on both stack current and input fuel flow variation, should be kept between upper and lower limits to avoid damaging fuel cell stacks. In this paper, a linearized model of fuel cell is obtained and the input stack current is considered as a disturbance. Then, a controller is designed using the H-infinity control approach. This controller works for standalone fuel cells. Two case studies are given to illustrate the proposed approach.