In this chapter we shall describe modern practices to improve the operational flexibility of conventional power plant, including characteristics of highly automated systems designed to improve start-up times and reduce the operator's role in direct plant control, in both normal and abnormal situations. We shall also examine the design outlines of modern boiler/turbine coordinated controls to provide fast ramping capability and wider, more stable frequency regulation performance.

Chapter Contents:

• 11.1 Features of highly automated power plant
• 11.2 Features of operationally flexible plant
• 11.3 Benefits of highly automated plant
• 11.4 Design principles for high-level automation
• 11.4.1 Hierarchical sequence design
• 11.4.2 Extensive plant self-protection and situation recovery control actions
• 11.4.3 Improving modulating controls design
• 11.4.3.1 Applying a 'remain on auto' principle
• 11.4.3.2 Advanced control strategies
• 11.4.3.3 Enhanced PID control
• 11.5 Boiler–turbine coordination: control design for operational flexibility
• 11.5.1 Understanding boiler and turbine steam dynamic responses
• 11.5.1.1 Stepping the throttle valves
• 11.5.1.2 Stepping the fuel
• 11.5.1.3 Response modelling
• 11.5.2 Coordinated modes for MW control
• 11.5.3 Coordinated Turbine Following
• 11.5.4 Unit Coordinated (also referred to as C-BF) mode
• 11.5.5 Components of the Unit Coordinated controls
• 11.5.5.1 Setpoint delays and overfiring
• 11.5.5.2 Throttle valve demand feedforward
• 11.5.6 Frequency response
• 11.5.7 Capability limits and runbacks
• 11.6 Summary
• References

Inspec keywords: power plants; boilers; turbines; power generation control

Other keywords: automated systems; operational flexibility; plant automation; boiler-turbine coordinated controls; frequency regulation performance; conventional power plant; direct plant control; fast ramping capability

Subjects: Thermal power stations and plants; Control of electric power systems