SYNCHRONIZATION....

Synchronization means connecting parallelly two vector quantities which are identical. i mean two vector quantities having same magnitude and phase angles and same phase sequence and angular velocity.

Mostly synchronization comes at breaker,generator,transformer which are going to connect parallelly. The main conditions to be satisfied for parallel operation.
       1. Voltage should be equal
       2. phase angle should be equal.
       3. phase sequence should be equal.
       4.angular velocity.
 The newly connecting machine should satisfy all above conditions with already running machine.other wise circulating currents will flow between machines and they will heat up the machines grid failure may occur.
      For checking synchronization we use a device called synchroscope.


we use generally two methods called
            1.bright lamp method
                           this method is used to compare opposite phase vectors(R1,Y2 and Y1,B2 and B1,R2 etc...),when they are equally out of phase then lamb illuminates bright light,then we can connect parallelly at that time.
            2.dark lamp method
                          this method is used to compare same vectors (R1,R2 and Y1,Y2 and B1,B2) , when they are equally in phase with equal voltage then lamb become complete dark,then we connect parallelly at that time.

          DIFFERENCE BETWEEN SYNCH CHECK and SYNCHRONIZATION.....

SYNCH CHECK: When the two incoming lines are need to connect to same busbar then the BCU( bay control unit will just compare the parameters like voltage,phase angle ,phase sequence and if those are with in the limits then BCU will give close command to breaker , other wise it will not release command.
                 Generally located at substations.

SYNCHRONIZATION: When the running generator is need to connect to running line then synchronization relay will compare parameters and if satisfy then it will give command to breaker,otherwise it will give command to AVR of generator to increase or decrease voltage levels, give command to speed governor increase or decrease the frequency of generator, after matching parametrs it will issue command to breaker.
                 Generally located at power plants.


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