Nonlinear coordinated control of drum boiler power unit based on feedback linearization

This paper analyzes the feasibility of applying feedback linearization technique to the nonlinear control of superheater steam pressure and power output of a boiler-turbine generating unit. A nonlinear coordinated controller has been designed and evaluated through computer simulation using a well-established and validated nonlinear boiler-turbine model. The simulation results are presented to illustrate the performance of a nonlinear coordinated control system and compare the proposed strategy with the conventional direct energy balance control strategy. The simulation results show that improvement can be achieved in control with a nonlinear control system. The real benefits obtained include improved dispatch rate, tighter regulation of steam pressure, and reduced maintenance over a wide range of operating conditions, and these improvements in control can be maintained for large changes in operating conditions.