Electric Part of the Turbine Control and Protection System
System Specifications
100% redundancy (including RTU modules)
Generation of control actions in 10 ms
Protection against issuing false control signals
Archiving in 10-ms, 100-ms, and 1-s intervals
Implementation of hot standby redundancy of control channels for 20 ms
Hot-swapping of the PLC modules
Heavy-duty operating conditions
Mean time between failures of at least 100,000 hours
Rapidly and continuously changing technological processes in the turbines require reliable high-speed control systems with an emergency shutdown (ESD) function. For the implementation of this functionality in the upgrade of the existing control systems were selected Redul B600 and Redul B500 controllers.
The system was developed for the use with gas and steam turbines and was used as a replacement of the OEM control system for the turbines. The system focuses on implementing maximum level of redundancy and tolerance to failures, delivering increased availability. Open approach and flexibility in extending allows implementation of other systems for the turbine with Redul controllers and use of only one software and one logic for the complete range of systems.
The system can automatically control a steam turbine in standard and emergency modes (of generation unit and of the power system), while monitoring load, live-steam pressure, positions of the control valves, signals from control devices at power unit/station/system.
Turbines that are currently in operation with this system vary from the small turbines for industrial applications to 800 MW turbine used in power generation. The system can be extended to provide participation of the turbine in primary and secondary frequency control
The redundancy is implemented at the levels of PLC, control, measurement equipment. And the solution provides timely diagnostics of the individual systems and control circuits of the actuators.
Implementation of the solution with the use of REDUL B600 (B500) PLCs allows a flexible configuration, connection to a remote SCADA (with support of the most common vendors on the market). Hot-standby operation of the CPU units and hot-swappable modules allow for a stable and continuous operation of the system.
Protection
Implementation of the protection algorithm on the Redul controllers benefits from their increased fault tolerance and improves level of protection of your equipment while reducing frequency of maintenance.
Turbine protection against an inappropriate reduction in steam pressure
Activation of the control and shutoff valves in case of increased frequency and acceleration
Turbine shutdown (via relay channel) without disconnecting the generator from the grid
Short- and long-term emergency load release of the power unit, with restoring load by the signals from emergency automation. By the conditions for dynamic and static stability.
Activation of the turbine’s control valves when the electrical load has dropped
Deep system diagnostics
Control
High speed of operation of Redul controllers allows you to implement more efficient algorithms in operation and deliver higher performance of the turbine.
Control of turbine rotation speed
Steam pressure control, with alignment to the power system frequency
Pressure control throttle (adjustment of live-steam pressure before the turbine)
Sliding pressure operation (control mode with variable live-steam pressure)
At the core of the system are DA03011 / DA03021 counter modules that feature:
Frequency measurement over three independent channels in two ranges (up to 10 kHz or up to 500 kHz)
Provision of turbine overspeed protection via electronic overspeed trip firmware
Verification of the protection state on a stopped turbine or during idling via built-in generator
Receipt of signals from an incremental encoder (control of the actuator position)
Receipt of signals from flow meter and control of the calibration settings
