How to Synchronize Synchronous Motors and Generator to Power System

Synchronize Synchronous MotorsSynchronization is a method of alternators which is connected to the power grid.Today we are going to discuss the necessary steps which take into Synchronize  Synchronous Motors or Synchronous Generator.  There are specific methods are use to get synchronize the synchronous motor or synchronous generator to the grid. There are several things to get consider while synchronization of these synchronous motor and generator. following are the necessary steps to consider while synchronization of such machines.

How to Synchronize Synchronous Motors

The important things in parallel operation of the synchronous motors are Synchronization and real power sharing.

Before the breaker is closed we must ensure that the new generator compares to the system has following features such as.

  1. The same RMS voltage.
  2. The same frequency
  3. Same Phase sequence
  4. Same instantaneous phase position

The special equipment calls synchronous scope can perform all necessary action and close the breaker automatically.

If necessary we can use the manual mode of the synchronous copy to close the manual. Also possible is a simple 3 lamp arrangement to perform synchronization and this is very suited for the parallel standby generator. It uses the same principal of synchronizing.

How to Synchronize the Synchronous Generators


  1. Bring the generator speed closer to its synchronous speed and give excitation for its generator voltage which little below the system voltage
  2. Now three lamps which shown in above figure  show a slow sequence of dark, bright, dark bright,—(cycle time of dark- bright- sequence is determined by frequency difference)
  3. Raise the generator speed slowly till two -dark- bright- sequence stagnates and little further up to resume it again very very slowly. (now we are sure that the generator frequency is just above the system frequency) >
  4. Watch out few cycles of -dark-bright- sequence and just before the lamps get fully dark close the breaker. (So that the lamp will be fully dark at the exact instant of closing the contacts)

By following above methods synchronizing can do.  A closing of the breaker should be done at the correct instances to avoid detrimental electromechanical transient.

Before closing the break we should make sure that the generator frequency is just above the system frequency to avoid reverse power flow soon after this synchronizing.

An incorrect the phase sequence is identified by uncontrol -dark-bright- sequencer rate. In such cases, we should shut down the generator and change the generator terminal wiring and retry the synchronization process.

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