Power system operation and control

1. B.E. DEGREE EXAMINATION, OCTOBER 2013
Seventh semester
Electrical and Electronics Engineering
EE 2401 Power System Operation and Control
(Regulation 2008)
Time: Three hours Maximum : 100 Marks
Answer ALL the questions
Part A (10 X 2 = 20 Marks)
1. Define Spinning reserve.
2. What is meant by load frequency control?
3. State the advantages of state variable model.
4. Define area control error.
5. Draw a typical arrangement of a simple AVR.
6. What is a static VAR compensator?
7. List the constraints in unit commitment problem.
8. What is meant by incremental curve?
9. What do you understand by network topology?
10. What are the functions of SCADA?
Part B (5 X 16= 80 Marks)
11. (a)(i) Define the following:1) Hot reserve,2) Coldreserve, 3) Diversityfactor (6)
(ii)A Generator stationhasthe followingdailyloadcycle:
Time(Hours) 0-6 6-10 10-12 12-16 16-20 20-24
Load (MW) 20 25 30 25 35 20
Draw the loadcurve andcalculate (1) Max.Demand(2) Unitsgeneratedperday
(3) Average loadand(4) Load factor. (10)
(OR)
(b) Explainthe following:(i) Loadforecasting (ii) Economicdispatchcontrol (16)

2. 12. (a) Two synchronousgeneratorsoperatinginparallel. Theircapacitiesare 300 MW and 400
MW. The droop characteristicsof theirgovernorare 4 % and 5 % fromno loadto full load.
Assumingthatthe generatorsare operatingat50 Hz at no load,how wouldbe a loadof 600
MW sharedbetweenthem. Whatwill be the systemfrequencyatthisload? Assume free
governoraction. (16)
(OR)
(b) Developthe state variable model of atwoarea systemandstate the advantagesof the
model.
13. (a)(i) Derive the relationsbetweenvoltage,powerandreactive powerata node for applications
inpowersystemcontrol. (8)
(ii) Explainthe operationof staticVARcompensatorandstate itsadvantagesoverother
methodsof voltage control. (8)
(OR)
(b) Explainthe injectionof reactive powerbyswitchedcapacitorstomaintainacceptable voltage
profile andtominimize transmissionloss inapowersystem. (16)
14. (a) State the unitcommitmentproblem. Withthe helpof aflowchartexplainforwarddynamic
programmingsolutionmethodof unitcommitmentproblem. (16)
(OR)
(b)(i) Developaniterative algorithmforsolvingthe optimumdispatchequationof an‘n’bus
powersystemtakingintoaccountthe effectsof systemlosses.(8)
(ii) A powerplantconsistsof two200 MW units,whose inputcostdata givenby,
F1 = 0.004 P12
+ 2.0 P1 + 80 Rs/hr
F2= 0.006 P22
+ 1.5 P2+ 100 Rs/hr
For the total load of 250 MW, what shouldbe the divisionof loadbetweentwounitsformost
economicoperation?
15. (a)Brieflydiscussthe variousfunctionsof energycontrol centre. (16)
(OR)
(b) Explainthe fouroperatingstatesof powersystem inthe securityperspective withan
example. (16)