TG519 - (GE) EHC Mk-II (Lynn) Steam Turbine Controls

4 days - 2.6 Continuing Education Units Awarded

Control system reliability can be a matter of skilled routine maintenance activity and proficient troubleshooting capability.  Although this is true, knowing how to get there from here is complicated.  First, it is important to fully appreciate the “big picture” of steam turbine operations, both “on-the-grid” and “islanded”.  This Seminar begins with these concepts then proceeds to looking at the development of critical signals:  Speed Control, Load Control, Inlet Pressure Control, Extraction Pressure Control and, protective circuits.  In each of these circuits we look at operator inputs, equipment feedback, and the development of control signals.  Once personnel have a thorough understanding of the “big picture” and how all the primary control signals are developed, then we can begin to look at calibration procedures, routine preventive maintenance issues, and troubleshooting. 

Topics include: System Overview • Hydraulics • Mechanical Components • Speed/Load Control • Extraction Pressure • Trip Circuits • Line Up Diagram • Calibration and Troubleshooting

HPC Technical Services is prepared to instruct this Seminar as developed by equipment-experienced instructors. Troubleshooting experience is given. The instructional experience is unmatched. The dedication to our accomplishing stated Seminar objectives are a matter of policy.

Note:  Sometimes there is some confusion as to which control system you have.  The GE-MSTG Mk-II system typically applies to industrial sites (such as paper mills) and municipalities (users of smaller sized generators).  This MSTG-Mk-II system was designed and constructed in Lynn, MA, if that helps.  Large utilities should look at the LSTG-Mk-II system, HPC Seminar # TG504.

Demonstrate conceptual knowledge of how the control system responds to load and/or extraction pressure change.
Describe how control room input is processed within the control electronics.
Explain, in detail, the signal flow path for the major control parameters: i.e.; flow, load, pressure and speed.
State and explain the purpose of all significant interfaces between the control system and the machine (including other power plant equipment).
Perform routine circuit calibration using the OEM line up instructions and prints.
Demonstrate knowledge necessary to troubleshoot commonly experienced symptoms.

Seminar OUTLINE

1. Starting & Loading Instructions: Manual Starting, Operating & Shutdown Procedures, Automatic Setting of Startup Speed/Load Ramps/Holds
2. Turbine Control Mechanisms: Hydraulic Power Unit, Electrical Trip Device, V1 Operator, V2 Operator (depending upon unit application), Main Stop Valve
3. Control Drawings: System Architecture, Documentation and Nomenclature, Interconnection Diagram, Wiring Diagram, One-Line Diagram, Elementaries, Connection Diagram
4. Steam Turbine Control System: Control Functions, Monitoring Functions, Protective Functions, Test Functions, Automation Functions
5. Speed/Load Control: Speed, Primary O/S and Emergency O/S Signals, Development of Speed/Load Control, Normal Control of Speed, Droop Speed Control, Methods of Controlling Speed, Speed Schematic Diagrams, Normal Control of Load, Load Limit, Methods of Controlling Load, Load Schematic Diagrams, Print Reading Exercises, Problem Solving
6. Inlet Pressure Control & Limiting: Inlet Pressure Control Signal, Control & Limiter Signal, Normal Control of Pressure, Operator Displays, Schematic Diagrams, Problem Solving
7. Sliding Pressure Control: Development of Signals, Signal Processing, Set point Display, Schematic Diagrams, Problem Solving
8. V1 Control: Schematic Diagrams, Servo Output, Valve Linearization, Manual Set point Register, Speed/Load Summer,  Valve Operator Exercises
9. V2 Control & Extraction Pressure Control (if applicable to unit): Pressure Control Concepts, Schematic Diagrams, Control Description
10. Overspeed Protection
11. Emergency Overspeed Protection: Emergency Speed Probes, Emergency O/S Module, Emergency Trip Relay
12. Test Procedures: Conducting Tests, Stop Valve Tests, Overspeed Tests, Off-Line Tests
13. Troubleshooting Exercise