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Upgrading
obsolete control systems is a cost effective way
to improve the operation and
reliability of a steam turbine. ICS provides a range
of turbine controllers specifically designed as a modern
retrofit replacement for the Electro-Hydraulic
and Hydro-Mechanical control systems on most models
of steam turbine in the 2MW – 200MW range. ICS
steam turbine controls utilize the field proven STC2000
digital control system for Turbine-Generator control,
protection and sequential functions.
The STC2000 Control System overcomes
the limitations of Electro-Hydraulic and Hydro-Mechanical
governor and sequencing equipment,
while also implementing current control philosophies
and operational enhancements. The system provides
high availability and reliability, while digital electronics
provide exact and permanent calibration.
In addition to application specific
STC2000 Control System configuration, most retrofit projects include a
full installation
engineering package, and may also include actuator and instrumentation
upgrades and generator
control upgrades. Each application is fully factory tested
in the customer controller as a totally prefabricated
and tested unit before shipment.
Utility Steam Turbine
Applications
Applications for utility Steam Turbines are applied
for control of straight condensing, reheat and
non-reheat steam turbines up to 300MW. These upgrades
may include integrated generator
controls, generator
protection and excitation/AVR
upgrades, utilizing
the latest commonly available industry-standard digital
equipment.
Industrial Steam Turbine Applications
Applications for Industrial Steam Turbines cover
all straight condensing, non-condensing, and
automatic extraction steam turbines. Specific design
features
are incorporated to address control issues often
unique to process plants including paper mills,
oil
refineries, chemical plants, and other industrial
applications, generator and mechanical drive.
For
many extraction steam turbines faced with operation
limitations due to control problems,
a control upgrade
provides reliable, flexible and safe control
of the turbine in all operating modes and can allow
more
efficient operation of the turbine.
STC 2000 Steam Turbine Control Functions
The STC2000 automates all aspects of the turbine control,
protection, start-up, and shutdown sequences. It interfaces
directly to existing instruments, or to new devices
supplied by ICS as part of a valve actuator or instrumentation
upgrade;
- Governing - Steam Valve Control
- Sequencing
- Protection
- Monitoring
- HMI operator interface / data historian
- Vibration
Monitoring
- Control interface to generator / mechanical
drive
- Remote Monitoring and Communications
The STC2000 control software is built
from a library of proven Functional Control Algorithm
modules. This allows
ICS to use standard governor code, ensure a high standard,
proven software, and reduced commissioning time. Common
Functional Control Algorithms for Steam Turbine control
include;
- Inlet Pressure Controller
- Inlet Pressure Limiter
- Single & Multiple Extraction
Pressure Control
- Extraction Pressure Control
- Exhaust Pressure Control
- Inlet / Extraction Valve
Ratio Control
- Turbine Speed Control
- Generator load control
- Generator load limit
- Hotwell Level Control
- Generator Stator Temperature
Limiter
The STC2000 is very flexible, allowing
for a high degree of customization as required to incorporate
project specific unit or customer needs and features
not possible with black box controllers.
Integrated Compressor Controls
For compressor drive applications ICS offers a non-proprietary
train solution with significant cost savings when
compared to traditional ‘black-box’ approaches.
Anti-surge control, compressor control, and process
control functions are all tightly integrated with
the turbine control in a single high-performance
open-architecture controller.
Integrated Generator Controls
For generator drive turbines, ICS provides generator
controls, AVR and static excitation systems, and
generator protection modules as part of the same
package. The application of modern digital devices
provides exact control while serial communication
to the turbine controller provides a common database
with full status and trending of all systems on a
common reporting database to deliver seamless control
and protection in a clean upgrade package.
Control
Upgrade Benefits
- Reduces
costly shutdowns & avoids forced outages -
Increased reliability/availability means less
downtime.
Comprehensive data logging and
diagnostics
of machinery
variables for troubleshooting and analysis
simplify preventative maintenance
- Improved
performance - Auto
start-up/synchronization, better speed/load
control and AGC responsiveness,
with additional control schemes for plant
efficiency improvements
- Easier Maintenance - Features like auto testing
of valve/trip systems facilitate maintenance
- Additional
Protection - Automatic soft start-up and shutdown
sequences reduce thermal and dynamic
stresses on machinery parts. Monitoring of turbine devices
and new instrumentation adds protection
- Plant Control Integration – STC2000
communication to DCS/RTU/IEC devices using industry
standard protocols
- Optimizes output – By
removing operation limitations due to control problems,
the STC2000 provides precise
digital control of the turbine in all
operating modes and can allow more efficient operation
of the turbine/plant
- Reduced training
and spare parts costs - The system
is easy to use and requires minimal training
to operate. Non-proprietary hardware spare parts and available
from multiple sources.
- Eliminates Obsolete
systems
- Comprehensive upgrade
options – ICS
provides a comprehensive range of retrofit
upgrade package solutions for steam turbine valve actuators,
excitation/AVR, generator protection
systems, instrumentation and
monitoring provides as part of
an integrated upgrade package
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