Why DC excitation is used for alternators? Why cant it be AC?
Answer Posted / sangeetha.np
When it is of Ac it behaves like a transformer by means of
the induction principle as there are two windings ie
armature and field windings. So in order to produce a
constant mag field we go for DC.
| Is This Answer Correct ? | 11 Yes | 3 No |
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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
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