Why DC excitation is used for alternators? Why cant it be AC?
Answer Posted / saroj kanta nayak
DC Exciation is mostly used, Because We need a constand
magnetic field for ouy power generation. So DC Voltage or a
Natural Magnet can Solve this problem. As using a natural
magnet will be bulky,So insted we use DC windings with
inverter power which draws power from the same Generator
during generation.
| Is This Answer Correct ? | 19 Yes | 22 No |
Post New Answer View All Answers
How to know Resistance and Reactance value of main and aux winding of single phase capacitor start capacitor run induction motor to find capacitor value?
For a 6.6kV Motor it is recommended to do megger test with 500 V d.c and not more than 5kV d.c but the Hi voltage withstand test should be performed by 12kV AC. Why the dc voltage test should be limited but AC voltage withstand test could be with such a high voltage?
Why reactors use before incoming of ac vvfd drive?
what would happen if reactive power (kvar)is increased (more)or decreased (less)? how much exact reactive power should be maintained? and what should be done for that
TRAFO 1. WHY BREATHER IS USED. 2. WHY OIL GOES DOWN IN CONSERVATOR TANK. 3. WHY WE ARE TAKING OIL SAMPLE TAKING FROM BOTTOM OF TRANSFORMER. 4. HOW TO CHECK IR VALUE OF TRANSFORMER. 5. WHY OLTC HAVING BUCHHOLZ TRIP ONLY; WHY NO ALARM. 6. OFF LOAD TAP CHANGER OPERATION PROCEDURE. 7. TR. SHUTDOWN / ISOLATION PROCEDURE. 8. WHEN THREE TRS. IN PARALLEL, ONE TR. IS NOT SHARING THE LOAD – WHAT IS REASON AND WHAT YOU WILL DO. 9. WHY TR. HAS OLTC IN HV SIDE. 10. WHAT IS % IMPEDANCE. 11. WHY TR. RATING IN MVA. 12. WHAT IS VECTOR GROUP IN TR. 13. CONDITION FOR PARALLEL OPERATION OF TRS. 14. WHAT IS TERTIARY WINDING. WHERE IT WILL BE. 15. IF TR. TRIP ON BUCHHOLZ OR TAP CHANGER RELAY, WHAT YOU WILL DO. 16. DIFFERENCE BETWEEN OIL TEMP. AND WINDING TEMP. PROTECTION 17. HOW WINDING TEMP. IS MEASURED IN CAST RESIN TR. 18. DIFFERENT TYPES OF FAULTS IN TR. Trafo - Page-1 of 2 19. WHAT HAPPENS WHEN TR. CHARGED FROM LV. 20. WHAT WILL YOU DO IF MEGGER READING SHOWS ZERO BETWEEN LV WINDING AND EARTH. 21. CAN WE INTERCHANGE BUCHHOLZ RELAY OF MAIN TANK AND OLTC TANK. 22. IF THE LINE BETWEEN BREATHER AND CONSERVATOR TANK 23. LOCKED, WHAT WILL HAPPEN DURING LOAD CYCLE. 24. WHAT IS THE FUNCTION OF OIL SEAL IN BREATHER. 25. WHAT ARE LOCATIONS FOR BUCHHOLZ RELAY FIXED IN POWER TR. 26. WHAT ARE CHECKS IN POWER TR. DURING MAINTENANCE. 27. WHAT IS IMPORTANT WHEN WE CHECK OLTC OPERATION DURING MAINTENANCE. Trafo - Page 2 of 2
Why does the rotor rotate?
HOW TO WORK A VFD?SAY SIMPLE METHOD
when the time of backcharging the transformer three phases only enough or three phase with neutral is must.from these which one is the best one.
TCS IS IT COMPANY THEN WHY DO THEY NEED ELECTRICAL &ELECTRONICS ENGINEERS?
define superposition theorem thevnin theorem ,norton theorom?
what is mean by descripiency relay? & wht is its ansi code?
neutral earth resistance testing is it possible for transformer while in load condition
what is earthing.how we make it,describe briefly.
Define step response?
I HAVE A 50A MCCB AS PER DESIGN LINE WIRE CONNECT UPWORD SIDE AND LOAD IS CONNECTED TO DOWNWARD SIDE TO THE MCCB.IF NOW ANY ONE CHANGE SUPPLY & LOAD(WISEVERSA) WHAT HAPPENS ? DOES MCCB OPERATION OR WORKING FUNCTION NORMAL IF YES THAN WHY THERE ARE MARKED LINE & LOAD ON MCCB.