Fault-tolerant model predictive control (FTMPC) for the BioGrate boiler

The fuel bed height sensor is a critical element in the control of the BioGrate boiler. A fault appearing in this sensor greatly affects the control performance in the sense that air distribution in the BioGrate boiler deviates from its nominal distribution. To address this problem, a fault tolerant model predictive control (FTMPC) has been developed to accommodate the fault in this fuel bed height sensor by the active controller reconfiguration. In this fault tolerant strategy, water evaporation in the furnace is estimated by fuel moisture soft-sensor, and thermal decomposition of dry fuel is estimated by utilizing oxygen consumption. This renders the power output of the boiler to be accurately predicted and controlled. The proposed FTMPC is successfully tested with the BioPower 5 CHP plant data and the results are presented, analyzed, and discussed.