Page 212 - Electrician - TT (Volume 1)
P. 212

ELECTRICIAN - CITS




           •  EMF commutation to some extent armature reaction
           •  Interpoles are provided only for improving commutation

           •  The LPT is strengthened by Interpole TPT
           •  Machine with Interpole has 25% more capacity
           Parallel operation of dc generators
           Advantages of parallel operation
           -  Continuity of service

           -  Efficiency
           -  Maintenance and repair
           -  Increasing plant capacity
           -  Non-availability of single large unit
           Conditions of parallel operation

           •  Same voltage
           •  Same polarity
           •  Power rating need NOT be the same






























           Parallel operation of dc shunt generator

           •  generator 1 is connected &supplying to the load.
           •  Now generator 2 is to be connected in parallel.
           •  Start the prime mover of the generator 2
           •  Adjusted its speed is to the rated value.
           •  Close the switch S4 .
           •  The voltmeter connected across S2 measures voltage

           •  Adjust excitation of the generator 2 till the voltmeter reads zero.
           •  The zero on the voltmeter ensures that the voltage of incoming generator 2 is same as that of generator 1 or
              the bus bar voltage.

           •  closed the switch S2which connects the incoming generator 2 in parallel with the system.


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                                    CITS : Power - Electrician & Wireman - Lesson 30-37
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