The process of connecting two alternators or an alternator and an infinite bus bar system in parallel is known as synchronizing. Generally, alternators are used in a power system where they are parallel with many other alternators.
Actually, it is a way of matching the speed and frequency of an alternator or other source to a running network or grid. Once the alternator is connected to the grid it starts delivering power to the electric grid.
A stationary alternator is never connected to live to busbars because it will result in a short circuit in the stator winding (since there is no generated emf yet). Before connecting an alternator to the grid, the following conditions must be satisfied:
- Equal voltage: The terminal voltage of the incoming alternator must be equal to the bus-bar voltage.
- Similar frequency: The frequency of generated voltage must be equal to the frequency of the bus-bar voltage.
- Phase sequence: The phase sequence of the three phases of the alternator must be similar to that of the grid or busbars.
- Phase angle: The phase angle between the generated voltage and the voltage of the grid must be zero.