IEEE 122-1991 pdf download.IEEE Recommended Practice for Functional and Performance Characteristics of Control Systems for Steam Turbine-Generator Units.
Abstract:Minimum functional and performance characteristics related to speed/load-control systems for steam turbine-generator units that may be interconnected on a power system are recommended. The recommendations apply to the following types of steam turbines, rated at 500 kW and larger, intended to drive electric generators at constant speed without initial steam-pressure control, exhaust steam-pressure control, or either: (1) condensing or noncondensing turbines without initial steam-pressure control, exhaust steam-pressure control, including turbines used with reheat, regenerative feedwater heaters, or both; (2) condensing or noncondensing turbines with initial and/or exhaust steam-pressure control, including turbines used with reheat, regenerative feedwater heaters, or both; (3) automatic extraction and/or induction and mixed-pressure turbines. Emergency governors, other overspeed control devices, and, in general, devices that are not responsive to speed, are not covered.
keywords: Automatic extraction turbines, automatic induction turbines, condensing turbines, mixedpressure turbines, noncondensing turbines.
The purpose of this recommended practice is to recommend functional and performance characteristics related to speed/load-control systems for steam turbine-generator units that may he interconnected on a power system, such that this recommended practice may be included in prime-mover purchase specifications.
1.2 Scope
These recommendations apply to the following types of steam turbines, rated at 5(X) kW and larger. intended to drive electric generators at constant speed:
1) Condensing or noncondensing turbines without initial steam-pressure control, exhaust steam, pressure control, or either, including turbines used with reheat, regenerative feedwater heaters, or both. (See Figs I and 2).
2) Condensing or noncondensing turbines with initial steam-pressure control, exhaust steam-pressure control, or both, including turbines used with reheat, regenerative feedwater heaters, or both. ISee Figs 3. 7, 8(a), and 8(b)1.
3) Automatic extraction, induction, or both, and mixed-pressure turbines. [See Figs 4. 5, and 8(c)].
3.2 Speed/Load-Control System Components
3.2.1 Compensated Control System: An interconnected system that controls two or more variables (speed. load, pressure, etc.) with compensation designed to minimize the interaction between the controlled variables.
3.2.2 Control Mechanism: The control mechanism includes all systems. devices, and mechanisms between a controller and the controlled valves.
3.2.3 Control Valves: Those valves that control the energy input to the turbine and are actuated by a controller through the control mechanism.
3.2.4 High-Speed Limit (Speed/Load Reference): A device or input that limits the speed/load reference setting to a predetermined upper limit. This device may establish the upper limit of the synchronizing speed range.
3.2.5 Load Controller: The load controller includes only those components and control elements that are responsive to energy output and load reference and that furnish an input signal to the control mechanism for the purpose of controlling the load.
3.2.6 low-Speed limit (Speed/load Reference): A device or input that limits the speed/load reference setting to a predetermined lower limit. This device may establish the lower limit of the synchronizing speed range.
3.2.7 Pressure Control System: A system that controls the pressure at a sensing point in a designated location. Typically, it includes the pressure-sensing element, the controller, the control mechanism, and the control valve(s). [Sec Figs 8(a), 8(b). and 8(c)].IEEE 122-1991 pdf download.