Power substations contain expensive pieces of equipment. If protection is not installed then you can watch them explode. A piece of protection also has to do with safety of personnel for instance fast trip settings, disabling breaker reclose, arc-flash settings etc.
Direct Transfer Trips (DTT) are initiated from station relays when a serious event occurs in the substation. Some of these events are breaker failure, bus faults, transformer failure, etc. A lockout relay (86 device) is assigned to each event.
Direct Transfer Trip Scheme Read More »
Pilot relaying refers to the communication network implemented on the high voltage transmission line (T-line) to transmit “trip or don’t trip” signal to and fro between two or more substations. The intent here is to trip the circuit breakers as fast as possible when a fault strikes the T-line, therefore, protecting it.
Basics of Pilot Relaying & Application Considerations For Transmission Line Protection Read More »
The Directional Comparison Blocking (DCB) scheme is the most popular pilot relaying scheme, implemented to protect high voltage power lines. This scheme is more dependable than a permissive transfer trip scheme because it trips the breaker even when there is no carrier signal from the remote end pilot relay. Let’s dive into details.
Directional Comparison Blocking Scheme Read More »
Coordinating and setting protective devices is an art in itself. It’s mostly at the engineer’s discretion and the clients priority when finding the middle ground for device settings. In any case, the following items should be considered when coordinating protective devices:
Protective Device Coordination: Steps you should consider Read More »
