Energy cost optimal operation of belt conveyors using model predictive control methodology

Abstract

Open loop optimal control approach has been applied to operation efficiency of belt conveyors in our previous works. When applied to field conveyor systems, its optimal instructions may result in constraint violations because an open loop mechanism cannot deal with the disturbances from the coal consumption forecasting and the feed rate. In this paper, a closed-loop model predictive control (MPC) approach is proposed aiming at the above problem. A coal feeding process, containing 6 belt conveyors, in a coal-fired power plant is taken as a case study. The open loop control and the closed-loop MPC are both formulated for comparative study. The disturbance of coal consumption rate forecasting and the disturbance of feed rate are further imposed on the two approaches, respectively. The results show that both the two control approaches, with energy cost as their objective function, are capable to achieve energy cost optimal operation of belt conveyors. Furthermore, the closed-loop MPC approach excels the open loop optimal control in dealing with disturbances. Unlike open loop optimal control, MPC approach can get feasible solutions against the above disturbances by compensating them with its closed-loop control mechanism.