Automatic Synchronization of Alternator using Numerical Relays

A power generation and distribution system is made up of multiple generating units that are linked to a common grid and distribute power across a vast area. To fulfil the dynamic needs, many generators are linked to the bus-bar, with some operating as spinning reserves. To manage the communication between the operator and high voltage equipment, sophisticated synchronisation circuits and a large number of connections are required. This complicates maintenance and mandates the use of auxiliary relays to ensure isolation and appropriate grounding, further complicating matters. Connecting an additional generating unit to the grid necessitates synchronising the generator’s attributes with those of the grid, such as voltage, frequency, phase angle, and sequence. Improper synchronisation can result in catastrophic repercussions such as damage to individual producing units, power outages, and system instability. The Multilin D60 line distance protection numerical relay was used to construct an automated synchronisation approach in this article. By synchronising a 5 kVA laboratory generator with the bus bar, this approach was successfully validated.