Why Parallel Operation Of Alternator

All we know that the demand of power is increasing day by day. It is a challenging situation for power engineers to meet the power demand of a consumers. In practical, a single alternator cannot meet the power demand. Thus to meet the excess of power demand, additional ac generator or alternator are connected in parallel. If a single alternator can meet power demand, an outage of the alternator will cause interruption of power supply. On the other hand, paralleling of alternators ensures the supply of a part of the total demand when one alternator is out of order. Any number of alternator can be connected parallel as per the requirement of the peek power demand. A power plant always tries its best to produce economical power for its customers throughout 24/7 of a week and 365 or 366 days a year.

Reasons For Paralleling of Alternator

A single alternator may not meet the total power demand of the consumers. If several alternators are connected in parallel, then it is possible to shut down one or more alternators for maintenance without any interpution of power supply. It is possible to handle load growth by adding alternators without disturbing the original installation.

Conditions For Paralleling of Alternator

The terminal voltage of the incoming alternator must be the same as bus-bar voltage. The line frequency must be same at the paralleling point. The prime movers of all alternators should have relatively similar and drooping speed-load characteristics. During paralleling process, the incoming alternator should be in phase and it should stay in phase after paralleling under normal condition.