Generator Synchronization Procedure

Generator synchronization is the process of the closing circuit breaker after matching the generator frequency, phase angle & voltage magnitude with grid voltage frequency, phase angle & magnitude respectively. Simply it is used to close the circuit breaker after synchronization check.

Conditions:

In order to synchronize a generator to the grid, four conditions must be met:

1. Phase Sequence
2. Voltage Magnitude
3. Frequency
4. Phase angle

Synchronizing procedure

1. Once the engine starts running properly, synchronization is carried out.
2. In the Engine control room, Check the pressure gauges.
3. On the generator control panel, check if all the ground lights are working properly with adequate brightness.
4. Also check the synchronizing relays for open position. Bring the running or the lead generator to the desired optimum parameters: 480 volts and 60 hertz.
5. Bring the generator that is to be synchronized(in-coming) to the desired parameters. Now turn on the synchronizing relay and keep a close look at the needle.
6. The needle in the synchroscope will move at a varying speed initially. Adjust the speed of the generator by obtaining a steady slow motion of the needle in the clock wise direction.
7. Once the needle is moving at a steady speed, depress the breaker close button when the needle has traveled three-fourth of its way. Energize the breakers when the needle reaches a position similar to the 11' o clock position of a clock.
8. After doing this, check the parameters of the on-coming generator. They should be same as those of the leading generator. i.e 480 Volts and 60 hertz

After synchronizing

1. After the main job of synchronizing, the following steps are to be carried out.
2. Change the governor control to the off-going generator.
3. Now the load shown in the gauges by this generator should be removed off the system as soon as possible before it starts acting as load(reverse power). This can be done by quickly pulling the trip breaker as soon as the generator goes off-line.
4. Once the generator is offline, stop the engine using a toggle switch.
5. After turning off the engine, turn on the engine block heater.
6. At the end, take a proper look at the control panel gauges for adequate pressure and even distribution of load.

It must also be noted that load distribution can be adjusted by varying the fuel supply to the generator via its governor but for current sharing to be equal you would need to vary the excitation current which changes the power factor of the generator.

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 Reference:

 brighthubengineering.com

marineengineeringonline.com

Marine Engineers' World (Facebook)

 Bangladesh Marine Academy