Answer / k.prakashchandra

You can not have fixed north and south poles in the field
with AC

Answer / raja

When ac supply is provided, the poles will alternate between north and south pole for each half cycle of supply. so there wont be any magnetic interlocking with stator to run at synchronous speed as the polarity changes at the rate of supply frequency. hence for magnetic locking DC supply is used for excitation

Answer / sunit saini

the working principle of syn/mac. is mag. locking which is
not possible in ac

Answer / lokesh

We need a statoinary magnetic flux in synchronous machine,
this flux will be cut by the rotor.

Answer / anil

Yes we can have a ac in rotor.But then we will not call it as a rotor.It will be stationary but this rotor has to be connected to a 3phase supply .Then it will produce a rotating magnetic field which will interact with the stator and create emf.

Answer / ert

BT SUBMIITIN

Answer / shailesh_358

DC excitation provides high starting current required for
excitation

Answer / madhu

to make sym machine self starting

Where we can use 3.5c cables instead of 4c cables.Why?

4 Answers  

what is working process of star delta controlling circuit ?

0 Answers  

How many earthing pits are requier to disapper the surge current of one lighting arrester.

3 Answers  

difference between brush less & brush excitation in a generator?

1 Answers  

which metal use as a electrical shunt?

2 Answers  

how much load 15kva dg set can bear.with full explination and how to calculate?

2 Answers  

What is the difference of grounding and earthing?

6 Answers  

What is the diffrence between PS & metering CT (5p20,0.5 etc.)? Why in PS class CT only Vk is given ? Is PS class CT is more accurate than metering CT?

1 Answers  

Can we use a absolute encoder to show rpm of a motor ? what about the condition when power is off ? what is difference if a incremental one is used ?abanirout@gmail.com

0 Answers  

whenever any squirrel or a crow falls on the transformer input line then there is a big explosion and 440 volts of power is being discharged through the neutral line due to which appliances in off mode are also burned.we have earthing for the transformer as well as the bus bar chamber.why is it happening?

1 Answers  

When calculating the speed of a rotor required for a particular frequency of synchronous generator we use the equation 60f/p Is this p is the number of pole pairs of rotor & do we consider the number of pole pairs in the stator is 1?

0 Answers   UOM,

I am B.E.electrical engineer having 7 years of experience in Transformer testing upto 315 MVA.I want to khow how I can get the 'Electrical Valuer' License.

0 Answers