OP321 - Voltage & Frequency Controls

2 days - 1.3 Continuing Education Units Awarded

This Course covers the importance of voltage and frequency in the bulk power system. In order to respond to rapid, unexpected system voltage deviations, we need to carry sufficient reactive reserves to better respond to unannounced voltage fluctuations. In addition to these changing voltages, power system frequency varies due to the constantly changing load. This module is designed to present the day-to-day, hour-to-hour, minute-to-minute changes in system load that result in voltage and frequency deviations from the ?scheduled? voltage and frequency. Operations personnel, electrical supervisors and engineers should attend the Voltage and Frequency Module.

COURSE OBJECTIVES
Upon completion of this course, the participant should be able to:

1. Define true power and Reactive Power and the relationship between Reactive and Power and Voltage Control.
2. Define voltage deviations.
3. Discuss the causes and effects of high and low voltages.
4. Discuss voltage control equipment available and the role of the power system operator in the control of voltage.
5. Discuss the reactive capability of synchronous generators.
6. Explain the need to match generation to load and describe how the load/frequency relationship and system inertia contribute to frequency control.
7. Explain the principle of governor action and the contribution of generating unit governors to generation control.
8. Explain how the automatic generation control (AGC) system regulates frequency and controls interchange.

COURSE OUTLINE

1. Power
   1. True and Reactive Power
   2. Reactive Power and Voltage
   3. Reactive Power Flow
2. Voltage Deviations
   1. Voltage Deviations and Schedules
3. Causes and Effects of High/Low Voltage
   1. Causes of low voltage
   2. Trip of a Transmission Line
   3. Trip of a Generator
   4. Low Voltage and Shunt Capacitor Banks
   5. Excessive Power Flows Across The Power System
   6. Unscheduled Power Flows
   7. Overvoltage
   8. Long Term Overvoltages
   9. Causes of Short Term Overvoltages
   10. Load Rejection
   11. Harmonic Overvoltages
   12. Causes of Transient Overvoltages
   13. Switching Surges
   14. Lightning Strikes
   15. Effects of High and Low Voltage
   16. Effect of High Voltage on Transformers
   17. Effect of High Voltage on Customer Equipment
   18. Effect of High Voltage on Load Magnitude
   19. Effects of Low Voltages
   20. Effect of Low Voltage on Power System Equipment
   21. Effect of Low Voltage on System Load Magnitude
4. Voltage Control Equipment
   1. Use of Static Var Compensators
   2. Capacitors and Reactors
   3. Use of Transformers
   4. Role of the Power System Operator
   5. Indication of Voltage Deviations
   6. Responding to Low Voltage
   7. Responding to High Voltage
   8. Voltage Control Summary
5. Reactive Capability of Generators
   1. Excitation Systems
   2. Generator Reactive Capability Curve
   3. Thermal Unit Reactive Capability Curve
   4. Hydro Unit Reactive Capability Curve
   5. Constraints on the Capability Curve
   6. Dynamic Reactive Reserves
6. Energy Balances
   1. The Changing Load
   2. Need For Generation Control
   3. Definition of a Control System
   4. Consequences of Over and Under Generation
   5. The Load Frequency Relationship
   6. Non-Motor Loads
   7. Motor Loads
   8. Power System Inertia
7. Governor Control Systems
   1. Governor Control System Operation
   2. Mechanical Governor Assembly
   3. Governor Characteristic Curve
   4. Isochronous (Flat-Line) Governor Control
   5. Governors with a Droop Characteristic
   6. Achieving Droop in a Centrifugal Speed Governor
   7. Governor Control in the Interconnected Power System
   8. Frequency Trace to Illustrate Governor Response
   9. Generator Response and Droop Settings
   10. Same Size Units-Same Droops
   11. Same Size Units-Different Droops
   12. System Frequency Response Characteristic
   13. Frequency Bias
   14. Response to a Loss of Generation
   15. Limitations to Governor Response
   16. Droop Limitations
   17. Responsive Spinning Reserve and Ramp Rate
   18. Blocked Governors
8. Automatic Generation Control System
   1. The Automatic Generation Control
   2. Function of an AGC System
   3. Definition of a Control Area
   4. Interchange
   5. Actual Net Interchange
   6. Scheduled Net Interchange
   7. Inadvertent Net Interchange
   8. AGC System Operating Modes
   9. Constant Frequency Control
   10. Constant Net Interchange Control
   11. Tie-Line Bias Control
   12. The Ace Equation
   13. Frequency Bias Constant
   14. Example of Tie-Line Bias Control
   15. External Generation Loss
   16. Internal Generation Loss
   17. A1-Zero Crossing
   18. A2-Ld Compliance