Question { 5134 }

DISCUSS THE SHAFT MOUNTED D.C. GENERATOR
,BASED ON EXCITATION
SYSTEM IN ELECTRICAL SYSTRM

Answer

In AC generators two types of excitation systems are used
1. Static excitation system &
2. Brush less excitation system
In static excitation system generated AC is stepped down and
converted to DC using rectifier bridges and fed to the field
(Rotor) through slip ring and carbon brush.
In Brush less excitation system the rectifier bridges are
mounted on the shaft of the generator itself. The power for
this rectifier unit is obtained from a permanent magnet
generator mounted on the shaft. The advantage of this system
is that DC power can be directly fed to the field

Question { 27993 }

The normal highest generated voltage in India is
a) 6.6KV b) 132KV c) 11KV

Answer

normal generated voltages are 3.3kV, 6.6kV and 11kV and
highest generated voltage is 11kV and is stepped up to
required transmission voltage level ie 33kV, 66kV, 110kV,
220kV or 400kV

Question { 23848 }

Why high Voltages come in multiple of 11, like 11 KV, 33KV,
66 KV, 132 KV etc.

Answer

I dis agree with all the answers above.
There is no mathematical/electrical reason.
If form factor (1.11) or multiple is the reason what about
400kv and 765kV (Highest transmission voltages in India)

Question { RECPDCL, 10039 }

What is the value of 3 phase voltage?

Answer

415 Volts (line voltage)
240 Volts (Phase voltage)