Advanced Control of Superheater Steam Temperatures - An Evaluation Based on Practical Applications

Abstract Tight superheater steam temperature control is a precondition for obtaining long lifetime, high efficiency, high load following capability and high availability in modern power plants. The intention of this paper is to produce an evaluation on a general level based on several practical applications within the Danish power industry. Different types of advanced feedback control strategies have been implemented and compared – this evaluation includes conventional control, model-based control and fuzzy control. Furthermore, a feedforward strategy based on radiation pyrometry and adaptive filtering has been used successfully to improve the stability and availability of a power plant. It is suggested that further efforts be invested in the development of multivariable strategies and utilization of new instrumentation for feedforward control rather than into development of new feedback control strategies.