The Emergency Trip System (ETS) for turbines is designed to monitor certain parameters that significantly affect the safe operation of the unit. When these parameters exceed the safety operation limits, the system actuates the trip solenoid valve to control the turbine protection system, closing all steam inlet valves to the turbine, initiating an emergency shutdown. Additionally, it provides shutdown diagnostic information to systems such as SOE (Sequence of Events)
PLC-based ETS (ETS-LM)
Introduction
The PLC-based ETS-LM is developed based on the HollySys LM-G3 series PLC platform, which completes core functions such as data acquisition, calculation, and output. It is suitable for small turbine units. Using PLC system as the main controller has the advantages of fast response, high reliability, long life, centralized management, decentralized control, easy logic modification, convenient increase or decrease of protection conditions, etc.
System Features
· Rapidity: Support for redundancy configuration of the module and power supply, ETS system not affected when any set of PLC fails or any power supply disappears
· Safety: Input and output of the two sets of redundant PLC systems adopting relay for isolation and physical loop hard isolation to ensure system safety and stability
· Rapidity: System control cycle < 20 ms
· Anti-inteference: Anti-interference measures used for resisting various electromagnetic waves and communication equipment on site, and compliant with IEC61131-2 and IEC61000-4 standards
Integrated ETS (ETS-K)
Introduction
The integrated ETS-K adopts HollySys HOLLiAS ® MACS-K system as the platform, and redundant fast main controllers to form the ETS system, which continuously receives alarms and shutdown signals from the TSI system, DEH system and other equipment of the turbine generator set online, and performs comprehensive logic judgment. The system is suitable for medium and large turbine units. When the normal operation of the unit is affected, various protection signals such as shutdown, alarm and interruption of the unit are sent in time to make the turbine shut down safely, and provide shutdown diagnosis information for DCS and SOE systems.
System Features
· Reliability: Independent system, redundant configuration, independent redundant fast controller and redundant power supply
· Rapidity: IEC operation cycle of 10 ms, 20 ms, 40 ms, 50 ms
· Anti-interference: Anti-interference measures used for resisting various electromagnetic waves and communication equipment on site, and compliant with IEC61131-2 and IEC61000-4 standards
· Safety: Various trip commands, alarms, and partial relay control circuits, and automatically activating the shutdown solenoid to quickly close the steam inlet valve when a turbine generator fault or other fault occurs
T800N DEH
Introduction
The ETS-SGM adopts the HiaGuard safety instrumentation system (SIS) as its platform, which is independently developed by HollySys for the safety field of industrial automation and realizes emergency shutdown. HiaGuard is certified by TÜV (Rheinland Industrie Service GmbH) and meets SIL3 safety-related applications as defined by IEC 61508 (2010), and the safety-grade protection unit is a triple modular redundant system.
System Features
· Reliability: SIL3 security level, and two-of-three architecture with diagnosis (2oo3D) used to ensure system security
· Security: Support for degraded operation with a 3-2-0 mode, redundant configuration of I/O modules, seamless switching, and system availability of 99.999%
· Wide coverage: Fault diagnosis located to the channel level
· High performance: SOE accuracy of 1 ms
· Integration: Seamless integration with HOLLiAS ® MACS system, and support for integration with third-party DCS through the Modbus interface
· Scale: Up to 1 main cage and 6 expansion cages supported by a single station, and up to 1856 I/O points
Turbine Control System Overview
Introduction
As the three necessary systems for turbine control, DEH is mainly responsible for controlling the startup, speed increase, operating under load and load regulation of the turbine to ensure stable operation of a turbine unit. ETS is mainly responsible for automatically and quickly cutting off the steam intake of a turbine when a fault occurs to protect the unit. TSI can continuously, accurately and reliably monitor the important parameters of turbine startup, operation and shutdown through sensors. When the monitored parameters exceed the limit, it can accurately and timely reports alarms or shutdown signals.
Features and Advantages
· Intelligent Velocity Measurement: The DEH special speed measurement module (3 out of 2) adopts the latest all-digital circuit, which can generate primary frequency regulation quantity, and cooperate with the servo module to complete the fast primary frequency control function.
· Efficient Configuration: With built-in fast DP (redundant) bus and CAN (redundant) bus, the primary frequency control function adopts independent high-speed CAN bus fast communication loop technology, featuring quick response.
· Intelligent Servo: The DEH special servo module adopts the latest all-digital circuit, and cooperates with the DEH special speed measurement module to complete the fast primary frequency control function through the CAN bus.
· Redundancy and Reliability: Servo module adopts redundancy configuration. Any servo channel can realize online redundant hot standby, and can automatically switch to the standby module when it is judged that the working module is faulty, and the switching time of the servo module is ≤ 10 ms. Servo valve adopts redundancy configuration. Two servo valves receive command signals at the same time to drive the oil motive to act. When one of the servo valves is determined to be faulty, a closure command is issued to the lockout valve of that servo valve. Subsequently, the remaining servo valve takes over all operations while an isolation electromagnetic valve is actuated to cut off the oil flow. Additionally, a shut-off valve on the oil line is used to isolate the fault point for maintenance, ensuring the continuous operation of the unit.
· Quick Master Control: The minimum IEC operating period of the controller is 10 ms, which can meet the rapidity requirements of ultra-supercritical units.
· Fast Frequency Regulation: With qualified primary frequency regulation capability, DEH can make the regulation period lower than 30 ms (non-control period).
· High-Performance Hydraulic Control: The hydraulic control system utilizes an independent high pressure 14 MPa control oil source, and the control of the oil actuated motor is integrated into the servo control system. This hydraulic control system is capable of achieving an oil actuated motor response time of less than 0.3s.
Applicable Model
Technical Parameters
· Speed adjustment range: Turning gear speed at 120% of rated speed
· Speed measurement accuracy: ≤ ±1 r/min Load control range 0 to 120%, accuracy 0.5%
· Speed variation ratio: Continuously adjustable within a range of 3 to 6%
· Control system insensitivity: < 0.06%
· Maximum overspeed at full load: < 7% of rated speed and able to maintain idling
· Steam extraction pressure control accuracy: ±0.01 MPa (suitable for C/CC units)
· Steam extraction pressure unevenness: 0 to 20%
· System control cycle: < 50 ms
· Minimum IEC operating cycle: 10 ms
· Anti-interference measure: Resistance to interference from various electromagnetic waves and communication devices on site, complying with IEC61131-2 and IEC61000-4 standards.
Company Profile
Audited Supplier 
){kind=link}