G536 - (ABB) Unitrol^TM Excitation System

4 days - 2.6 Continuing Education Units Awarded
On-Site-Only

ABB Unitrol^TM Excitation System reliability and availability can be a matter of skilled routine maintenance activity and proficient troubleshooting capability. Proficient troubleshooting is greatly aided by a solid operational understanding of the excitation system.

This Seminar gives technicians and engineers the necessary knowledge to maintain, repair and calibrate the Unitrol Excitation System by:

1. Using effective routine maintenance practices.
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 how the equipment operates.
4. Increasing the likelihood of accurate problem diagnosis by understanding any given board's impact upon operations; ie., quickly linking the symptom(s) to the faulty board.
5. Verifying a suspected faulty board by analyzing voltage levels and/or signal traces.
6. Understanding the necessary calibrations, after the faulty part has been replaced, including how the calibrations are performed.

HPC's Excitation System Seminar makes heavy use of prints, on which the participants are encouraged to take notes. This provides a valuable reference for future use. In addition, the student manuals contain a complete description of the excitation system operation.

OBJECTIVES
Upon successful completion of this Seminar the participant will be able to:

1. Discuss how an excitation system accomplishes voltage and VAR control.
2. Discuss the primary and secondary roles of an excitation system.
3. Discuss the major excitation system components, including limit and protective features.
4. Discuss the Discuss the operation of each module found within the Unitrol^TM Excitation System.
5. With the use of prints, trace a given signal change through the excitation system.
6. Discuss routine maintenance including what can and cannot be done on-line.
7. Discuss troubleshooting of the Excitation System, including expected voltage/signal levels.
8. For a given symptom, list the most probable fault location(s).
9. Discuss the options available to quickly narrow down the fault location.
10. Discuss the necessary calibration, for each board, following board replacement.

Seminar OUTLINE

1. Introduction
2. Excitation Theory
3. AC Generators
4. General Excitation System Description
   1. System Purpose and Overview
5. Major Components
   1. Pilot Generator
   2. Automatic Voltage Regulator
   3. Manual Voltage Regulator
   4. Stationary Uncontrolled Rectifier
   5. Stator Current Regulator
   6. Excitation Current Regulator
   7. Rotor Angle/Load Angle Limiter
   8. Field Breaker and Discharge Resistor
   9. Follow Up Controller
   10. Power Stage and Grid Control
6. Routine Maintenance
7. Troubleshooting & Repair
   1. Six-step Troubleshooting Method
   2. Symptom Analysis
   3. Expected Voltage/Signal Levels
   4. Most Common Failures
   5. Post Replacement Calibration

Unitrol^TM is a registered Trademark of ABB