IEEE 122:1991 pdf download.IEEE Recommended Practice for Functional and Performance Characteristics of Control Systems for Steam Turbine-Generator Units.
These recommendations apply to the following types of steam turbines, rated at 500 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 1
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. [See Figs 3, 7, 8(a), and
8(b)].
3) Automatic extraction, induction, or both, and mixed-pressure turbines. [See Figs 4, 5, and 8(c)].
2. References
This recommended practice should be used in conjunction with the following publications.
111 ANSI C50.10-1990. American National Standard General Requirements for Synchronous Machines)
[2] ASME PTC 20.1-1977 (Reaf 1982), Speed and Load Governing Systems for Steam Turbine-Generator Units.2 131 ASME PTC 20.2-1965 (Reaf 1986), Overspeed Trip Systems for Steam Turbine-Generator Units.
[4] ASME PTC 20.3-1970 (Reaf 1980), Pressure-Control Systems Used on Steam Turbine-Generator Units. 151 IEEE Std 1(X)- 1988, IEEE Standard Dictionary of Electrical and Electronics Terms.3
[6] NEMA SM 23-1985, Steam Turbines for Mechanical Drive Service.4
171 NEMA SM 24-1985, Land Based Steam Turbine Generator Sets, 0 to 33 (XX) kW.
3. Definitions and Descriptions of Terms
All definitions, except as specifically covered in this section, are defined in IEEE Std 100-1988 [5]
3.1 Types of Steam Turbines
3.1.1 Straight Condensing Turbine: All the steam enters the turbine at one pressure and leaves the turbine exhaust at a pressure below atmospheric pressure. (See Fig 1).
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.IEEE 122 pdf download.