Sri Venkateswara Institute of Medical Sciences (SVIMS) 2007 B.Tech Electrical and Electronics Engineering power systems-1 - Question Paper

FOUR YEAR B.TECH DEGREE EXAMINATION, NOVEMEBER 2007
3rd year exam
1st semester
electrical and electronics engineering
POWER SYSTEMS - 1
TIME : three HOURS Maximum:100 Marks
Answers any 5 questions, choosing onequestion from every unit.
All ques. carry equal marks.
Assue any missing data suitably
Unit - 1
1. (a) describe base load, peak load, load duration curve,types of loads. (8 marks)
(b) A generating station has a maximum demand of 75 MW and ayeariy load factor of 40%.Generating costs inclusive of station capital costs are Rs. 60 per annum per KW demand plus four paise per kWh transmitted. The annual capacity charges for transmission system are Rs. 20,00,000 and for distribution systems Rs. 15,00,000 the respective diversity factors being 1.2 and 1.25. The efficiency of transmission system is 90% and that of the distribution system inclusive of substation losses is 85%. obtain yearly cost one KW demand and per kWh supplied. (a) at substation .
(b) at consumer premises. (12 Marks)

or

2.(a) Write expression for cost of electrical energy and 2 methods for determining depreciation. ( eight marks)
(b) A hydroelectric plant costs Rs. 3,000 per KW of installed capacity. The total annual charges consists of 5% as interest, depreciation at 2% operation and maintenance at 2% and insurance, rent, etc at 1.5%. Determine a sutiable 2- part traiff. If the losses in transmission and distribution are 12.5% and diversity of load is1.25. presume that Maximum demand on the station is 80% of the capacity and annual load factor is 40%. What is the overall cost of generation per kWh. (12 marks)

Unit - 2
3. (a) discuss Kelvin's legal regulations . state its limitations. ( eight marks)
(b) A three phase overhead transmission line supplies a constant load of six MW at 33 kv nad 0.8 p.f. lagging through out the year. The cost of line is Rs.( 80000 ? + 3500)/km where '?' is the cross part of every conductor in cm². The cost of energy is 25 P/kWh nad interest and depreciation total 10% /annum. assuming specific resistance of conductor material at 1.8 µ? cm, obtain the economical size of conductor. (12 marks)

or

Earning:   Approval pending.