Modelling and multi-loop selective control of industrial coal pulveriser

Coal-based power generation continues to be a key player in power generation. Pulverisation of coal is an important, but an energy intensive process. Efficient control of the pulveriser can improve the efficiency of the power plant, which otherwise lies in the range of 30-40%, a rather low value. This paper discusses various computational results and their analysis for the case study carried out at ESSAR thermal power plant, Hazira, Gujarat, India. It proposes more accurate mathematical model for a pulveriser and a 3PI (proportional integral) with selective control for improved performance. The model is validated with real plant data and is observed to capture system dynamics more effectively than the models existing in the literature. It is observed that the new model with proposed control has better load disturbance rejection properties and is more robust to parametric variations compared to the control strategy employed in the industry.