TG508 - (GE) DCM+ Steam Turbine Controls

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4 days - 2.6 Continuing Education Units Awarded


Control system reliability can be a matter of skilled routine maintenance activity and proficient troubleshooting capability.

  1. Using effective routine maintenance and calibration procedures.
  2. Knowing what checks may be performed on-line and how to perform these checks without causing an equipment shutdown.
  3. Increasing the likelihood of accurate problem diagnosis by thoroughly understanding any given circuits impact upon operations; i.e., ask the proper questions to properly identify the symptoms and then identify the problem.
  4. Quickly determining whether the problem is more likely electrical or mechanical/hydraulic.
  5. Properly analyzing V1/V2 Control input/outputs.
  6. Properly analyzing Inlet / Sliding Pressure Control inputs, outputs and internally generated signals.
  7. Properly analyzing Speed/Load Control input/outputs.
  8. Properly analyzing Protective Circuits as well as Overspeed Trip functions.
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.

Upon completion of this Seminar the student should be able to:
  1. Perform routine circuit calibration using the OEM line up instructions and prints.
  2. State the control system response to each control room input.
  3. State the control system action that led to each machine and/or control room output.
  4. Explain, in detail, the signal flow path for the major control parameters: i.e.; flow, load, pressure and speed.
  5. State and explain the purpose of all significant interfaces between the control system and the machine (including other power plant equipment).
Seminar OUTLINE:
  1. Starting & Loading Instructions
    1. Manual Starting, Operating & Shutdown Procedures
    2. Automatic Setting of Startup Speed/Load Ramps/Holds
  2. Turbine Control Mechanisms
    1. Hydraulic Power Unit
    2. Electrical Trip Device
    3. V1 Operator
    4. V2 Operator (if applicable)
    5. Main Stop Valve
  3. Control Drawings
    1. System Architecture
    2. Documentation and Nomenclature
    3. Interconnection Diagram
    4. Wiring Diagram
    5. One-Line Diagram
    6. Elementaries
    7. Connection Diagram
  4. Steam Turbine Control System
    1. Control Functions
    2. Monitoring Functions
    3. Protective Functions
    4. Test Functions
    5. Automation Functions
  5. Speed/Load Control
    1. Speed, Primary O/S and Emergency O/S Signals
    2. Development of Speed/Load Control
    3. Normal Control of Speed
    4. Droop Speed Control
    5. Methods of Controlling Speed
    6. Speed Schematic Diagrams
    7. Normal Control of Load
    8. Load Limit
    9. Methods of Controlling Load
    10. Load Schematic Diagrams
    11. Print Reading Exercises
    12. Problem Solving
  6. Inlet Pressure Control & Limiting
    1. Inlet Pressure Control Signal
    2. Control & Limiter Signal
    3. Normal Control of Pressure
    4. Operator Displays
    5. Schematic Diagrams
    6. Problem Solving
  7. Sliding Pressure Control
    1. Development of Signals
    2. Signal Processing
    3. Set point Display
    4. Schematic Diagrams
    5. Problem Solving
  8. V1 Control
    1. Schematic Diagrams
    2. Control Description
      1. Servo Output
      2. Valve Linearization
      3. Manual Set point Register
      4. Speed/Load Summer
    3. Valve Operator Exercises
  9. V2 Control & Extraction Pressure Control
    1. Pressure Control Concepts
    2. Schematic Diagrams
    3. Control Description
  10. Overspeed Protection
  11. Emergency Overspeed Protection
    1. Emergency Speed Probes
    2. Emergency O/S Module
    3. Emergency Trip Relay
  12. Test Procedures
    1. Conducting Tests
    2. Stop Valve Tests
    3. Overspeed Tests
    4. Off-Line Tests
  13. Troubleshooting Exercise
  14. Conclusion