WHY EXCITATION OF SYNCHRONOUS MACHINE IS DC NOT AC
Answer Posted / 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
| Is This Answer Correct ? | 18 Yes | 0 No |
Post New Answer View All Answers
How to calculate per unit impedance of transformer?
WHAT ARE THE DATAS REQUIRED FOR PROTECTION AND METERING AND CONTROL AND LOGIC PREPARATION,HOW TO STUDY THE PROTECTION AND METERING?
how to get electrical supervisor competency certificate in gujarat. i did 3 year diploma in electrical
234 MVA Generator 3 phase Short circuit current Values required? Gen set Rating-234 MVA, Gen Voltage-18kv, PF;0.8, Xdv:23.5 %, Transformer Rating-18/380KV, 680MVA,Yndd1 two winding, Step up TR, ZT:35.50 %,X/R 4.33 Gen CB Position, CB open ,Disconnected open, Generator Running Voltage 18 Kv, Bi mistakes generator side earth switch Closed during that time short circuit current level in 3 Phase required, and how to test on site 234MVA Generator Short circuit current,
Determine the BTU size of an aircon for 20 sq metre room
Draw a 230kv two-bus bar system showing the following. 1.Two generators (150MW) each connected through one 15.75/230KV transformers 2. 1 outgoing lines 3. Two 230/130 KV transformers 4. BUS PT's 5. CT
why dc is used in control circuit for mv & hv switchgear instead of ac
what is the setting of locked rotor in HT motor ? (answer expecting in percentage)
how net resistance islow in star connection and viseversa in delta connection...? if anybody could explain in detail it wud be helpful.
the winding of Generator and Motor is star or in delta ? and why
How we can change the direction of rotation of Induction motor? Prove it using graphical
Why are cables rated for 40 KA for 0.25 Sec fault current rating?
As we know induction squirrel cage motor torque Directly praprortinal to applied voltage in star connection & delta also. If I connect 55KW Motor to DOL starter in load condition does motor withstand the load & what will be the current withdrawn ? motor will not fail ?
difference between the applicability of nortons and thevenin theorem
How to checked frequency drive output voltages?