Answer Posted / bikki

In HT transformer, the primary side has less voltage stress since it is a step up transformer. But the voltage on secondary side will be high and hence the stress will be also high.As a result, the winding insulation requirement will cost a lot if the connection was Delta on secondary side;because in delta phase voltage=line voltage.
But if the secondary connection is star, then phase voltage will be Line voltage/(sqrt(3) which means the winding has to withstand less voltage stress and hence less insulation is required.Hence lesser cost.

sir, I am from EEE branch.On feb 17 iam going to write an Exam for hindustan petrolium corporation Ltd.So plz send me the written exam pattern/Q's/interview questions.please mail to eee_dharmendra@yahoo.com

1789

---

what is earth fault relay 64T, why it is used in main Incomer and neutral CT of Transformer.

3717

---

how much leakage current is allowed in MC61A L&T make relay?

3608

---

What is the limitation of kirchoffs law?

1063

---

why do we have spikes enough to burn electronic boards, when generators are not grounded

1757

---

i want to learn control schedule for 11kv panel? can any one send the detailed control schedule?

2370

---

How to Prepare preventive maintenance shedule of machine tool.

1958

---

why would amp draw on neutral wire be as much as amp draw on the hot leg.

2047

---

Is there any question in the name of Static Switch in UPS??

1908

---

if 12v battery get discharged for 2 months after if we put charge it will charge again?how much time it will take to charge?

1876

---

why normally Generator rating are between 11Kv to 22Kv?

4533

---

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

2350

---

(1)The demand for electricity , the amount of renewable generation available, the amount of fossil fuel generation available and the cost of the fossil fuel generation are shown in table below period(hrs) demand(MW) renewable (MW) fossil- fuel(MW) cost of fossil fuel(MW) 00.00 - 01.00 2000 1800 2000 30 01.00 - 02.00 2300 2500 2000 30 02.00 - 03.00 2500 2700 2100 45 03.00 - 04.00 2900 3100 2100 50 04.00 - 05.00 2700 2600 2500 45 05.00 - 06.00 2400 2000 2700 50 06.00 - 07.00 2200 1800 2000 36 07.00 - 08.00 2100 1600 2000 36 Assuming that the renewable generation incurs zero cost, determine an optimal generation schedule(specifying the amount of renewable generation and fossil fuel generation used in each period, the cost for each period and the overall cost for 8 hours.)

1797

---

how much cable size required for 70 kilowatt load.

1622

---

DG SET BLOCK DIGRAM

2235

---