Relays 2
COURSE DESCRIPTION
An electric power system includes generators, power transformers, transmission lines, switchgear, distribution circuits, and residential and business customer equipment. At any time, severe weather, accidents, or other factors may cause part of the system to fail. If the system is not properly protected, a failure can result in personal injuries and extensive equipment damage. One of the keys to protecting equipment and personnel from failures is the use protective relays.
COURSE GOAL
This training program examines the functions and operation of some types of protective relays that are commonly found in substations and switchyards.
SUBJECTS AND OBJECTIVES
Introduction to Relays
Identify five common relay elements
Identify the functions of overcurrent, directional overcurrent, reclosing, voltage, and auxiliary relays.
Differential Relays
Identify what differential relays typically protect.
Describe the condition that causes a differential relay to operate.
Describe the basic operating principles of differential relays.
Transfer Tripping
Describe the function of transfer tripping.
Identify the main components of a transfer tripping system.
Identify four communication channels used for transfer tripping and explain how they work.
Identify the main equipment associated with transfer tripping communication channels and describe the function of each type of equipment.
Distance Relays
Identify what distance relays typically protect.
Describe the condition that causes a distance relay to operate
Describe the basic operating principles of distance relays.
Pilot Wire Relaying
Describe the function of a pilot wire relaying system.
Identify the main components of a pilot wire relaying system.
Describe the basic operating principles of a pilot wire relaying system.
Breaker Failure Relaying
Identify the function and the main components of a breaker failure relaying systems.
Describe the general operation of a breaker failure relaying system.
Describe the basic operating principles of a breaker failure relay.
Describe the basic operating principles of a timing relay in a breaker failure relaying system.