Re: synchroniziation ?

Spir Georges GHALI

nagaraju said:

Dear Engineers,


I want to be know about synchroniziation with full fledged details,regarding example of generators and transmission lines also

thanking you.

Dear ;


We use the Synchronization to be able to connect 2 sources on parallel to the same bus-bar, so, to do it we should realize the following conditions :

– The Value of ” Voltage ” for both should be exaclty the same.

– The Value of ” Frequency ” for both should be exactly the same.

– The direction of ” Rotation ” of pahses should be the same.

– There's no any ” Phase shift ” between them at the moment of connection.

– It will be better that :

     – The powers are the same.

     – The specifications are the same.

     – The manufacture for both is the same ( to be sure that they have the same specifications ).


There's now special equipments that can do it automatically, or another can provide a signal once these conditions are realized, so, we can connect them manually but in this case it should be done immediately after the signal.


Assume that we want to connect 2 generators on parallel, where they have the same specifications mentioned above, in this case, at least one of them should have the possibility ” manual  or  Electrical ” to adjust : the Voltage and the Frequency ( by changing the r.p.m. of the engine ) that will be used to adjust these values to be the same as the 1st source. The procedure to connect them is as follow :

– We run the 1st generator, close the relative CB, so the Synchronization equipments will measure the ” Voltage & frequency ” for it.

– We run the 2nd generator, so, the Synchronization equipments will measure the ” Voltage & the frequency ” for it, and in the same time the ” Shift phase ” apparatus will measure the ” Shift angle ” between them.

– We adjust the ” Voltage ” value for the 2nd to be exactly as the 1st.

– We adjust the ” frequency ” value for the 2nd to be exactly as the 1st.

( these adjustments can be done also automatically by the Synchronization equipments if the 2nd generator is equipped ).

– If the connection will be done automatically, the Synchronization equipments will do it once the conditions are realized, but if will be done manually, we should monitor the ” Shift phase ” apparatus and once the value of the shift angle is ” 0 ” we close immediatly the CB for the 2nd generator.


If the powers of these 2 generatos aren't the same,in this case we should use also the ” Load Shearing Apparatus “.