Design of MPC for Superheated Steam Temperature Control in a Coal-fired Thermal Power Plant

A superheater is an essential part of the steam generation process in the boiler-turbine system. Reliable control of temperature in the superheated steam temperature system is necessary to guarantee efficiency and high load-following capability in the operation of coal-fired Thermal power plant. The PI and PID controllers are extensively used in cascade control of secondary superheated steam temperature process.The design and implementation of a Model Predictive Control (MPC) strategy for the superheated steam temperature regulation in a thermal power plant is presented. A FOPTD model is derived from the dynamic model of the superheater. This model is required by the MPC algorithm to calculate the future control inputs. A MPC controller is designed and its performance is tested through simulation studies. Compared with the superheater steam temperature control using a conventional PID controller, the steam temperature controlled by the MPC is found to be more stable.