System Protection Technology

The objective of this videotape is to demonstrate the various methods that are used to investigate equipment performance during fault conditions. While various types of fault recorders are considered, particular emphasis is placed upon the interpretation of oscillograms.

After study of this tape and the associated workbook participants should be able to understand the following overall concepts and be able to apply them to their day-to-day work activities. They will also be able to answer related test questions on these subjects:

• Objectives of fault investigation and analysis
• Disturbances, faults, power swings
• Gathering of fault data (after the fact)
• Operational reports, relay targets
• Sequence of event recorders (SOER)
• Oscillograms from digital relays
• Features of oscillograph machines:

1. quick start
2. pre-fault
3. continuous

• Starting sensors:

1. neutral overcurrent
2. zero sequence voltage
3. negative sequence voltage

• Location of oscillographs on the power system
• Selection of data to be monitored
• Information available from oscillograms
• The need to monitor carrier signals
• Coordination of data from all sources for analysis, i.e. relay targets, operational reports, system one-line diagrams, oscillograms and SOERs.
  Interpretation of data