Bee4173 - Power System Operation & Control

8/12/2019 Bee4173 - Power System Operation & Control

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F 1 Univers i t ia lays iaP H N GFACULTY OF ELECTRICAL ELECTRONICS ENGINEERING

FINAL EXAM INATIONCOURSEOWER SYSTEM OPERATION CONTROLCOURSE CODEEE4173LECTURERUHAMM AD IKRAM BIN MOHD RASHIDDATEJANUARY 2012DURATIONHOURSSEMESTERISESSIONEMESTER I SESSION 2011/2012PROGRAMME CODE :EPINSTRUCTIONS TO CANDIDATESThis question paper consists of F OUR (4) questions. Answer A LL q uestions.2 All answers to a new question should start on new page.3 All the calculations and assumptions must be clearly stated.4 Candidates are not allowed to bring any material other than those allowed bythe invigilator into the examination room.

EXAM INATION REQUIREM ENTSAPPENDIX Table of formulas

DO NOT TURN THIS PAGE UNTIL YOU ARE TOLD TO DO SO This examination paper consists of SE VEN (7) printed pages including front page


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CONFIDENTIALEP 111211BEE4173QUESTION 1a) Define an econom ic dispatch in pow er system.[2 M A R K S ]

[ C O 1 P O 1 C 1 ]

b) A system consists of 2 plants connected by transm ission line and a load only atplant. The tw o plants incremen tal fuel cost in RM /M W h are approximately:

0.01P1+8.5= 0.015P + 9.5

When 2 MW is transmitted from S t plant to 2 plant the power loss in thetransmission line is 16 M W . Determine:i) The req uired econom ic generation for each plant.ii ) The pow er received by the load for a system which equal to 12.50 R M /MW h.

[ 10 M A R K S ][ C O 3 P 0 3 C 3 J

G 1:DLoadFigure 1

2


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CONFIDENTIALEP 111211BEE4173c) Consider 3 gene rators Gi, G2 and G 3 operating in the pool system with loads 1 and 2which shown in Figure 2 Each generator has a maximum capacity and bid price fortheir power indicated in Table 1 below. Loads 1 and 2 are 360 MW and 140 MWrespectively. Each transmission line is limited to 100 M W .

Load 1oad 2Figure 2Tab le 1Generator Max Capacity MW ) Bid P riceGi 5 RM 15/MWhG2 200 RM2O/MWhG3 100 R1v125/MWh

Determine:

i) T he System Marginal Price SMP ), Pool Purchase Price PP P), and Pool SellingPrice PSP).

ii) Total generation income and demand charges for both unconstrained andconstrained dispatch. Loss of load Probab ility LO LP ) is assumed to be 0.

iii) Pool Purchase Price PPP) when LOLP is 0.00015 and VOLL isRM23 OOIMWh.

[ 3 MARKS][CO3 P03 C3]


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CONFIDENTIALEP 111211BEE4173QUESTION 2a) Draw a block diagram of a governor pr ime m over rotating mass load m odel .[ 6 M A R K S ]

[ C O 1 1 ` 0 1 C 2 1

b) 2 ident ical a lternators 4 MVA operate in paral lel. The governor o f the f i rst m achine issuch tha t drops f rom 50 Hz on no load to 47.5 Hz on ful l load . The correspondingdrop for the second m achine i s 50 Hz to 48 Hz. A load of 6 M W are shared by thetwo machines, determine:i) Power produced by each m achine to supply the loadii) System freq uency at this load

[ 9 M A R K S ][ C O 2 P 0 3 C 3 ]

c) Tw o areas conne cted by a t ie l ine with the characteristics given in Table 2:Table 2

Areal A reaR=0 Ol2pu R=0.O2pu

D=0 75pu D=1 2pu

MV A base = 500 MV A base = 500

A load chan ge of 20 M W o ccurs in area 1 . Assume bo th areas a t nominal f requency5014z) to begin. C alculate:i) Steady-state frequency for the systemii) Power change in t ie f low from Area 1 to Area 2iii) C hange in generat ion for each area

[ 10 M A R K S ][ C O 2 P 0 3 C 3 ]


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CONF]DENTIALEP 11121 BEE4173QUESTION 3(a) Consider a synchronous gene rator feeding into a power system as shown in Figure 3.

Prove all the expressions for active and reactive power can be given as:EVi sinS

EV= -i sin 5where

E EVQ 1 O S SEVQB kcosS x

P = real output powerQ = reactive output powerE = internal voltageo = phase displacement angleV = infinite bus voltageX = R eactance

IL

S LSLO SBFigure 3[15 MARKS]

[CO2,1`03,0]

(b) An alternator having reactance Xd of 0.35 Pu 1 S connected to an infinite bus through afeeder having reactance 0.35 pu. The alternator delivers 1.0 Pu current at 1.0 Puvoltage and pow er factor 0.86 leading to an infinite bus. Determine:(i ) P, Q , E and 8 at receiving end,(ii) If the excitation is increased by 15 , calculate P, Q, E and 8

[1 MARKS][CO2,1`03,0]

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Vs

C O N F I D E N T I A LEP 11121 /BEE4173Q U E S T I O N 4a) Define the term SC ADA and justify T H R E E 3 ) reasons why SCADA had beendesign in power system application?

[4 MARK S][ C 0 4 , P O 1 , P O 2 , P O 7 , C 2 ]

b) Briefly describe TW O 2) benefits of utilizing FACT S devices.[5 MARK S]

[C04 PO1 P02 P07 C2]

c) Discuss in brief the following term:i) Master unitsii) Rem ote units

[6 MARK S][C04,PO1,P02,PO7,C2]

d) Figure 4 show a 2 30 kV line is fed through an 33/230 kV transformer from a constant33 kV supply. At the load end of the line the voltage is reduced by anothertransformer of nominal ratio 230/11 Ky. The total impedance of the line andtransformer at 230 KY is 30+j80) ohms. Both transformers are equipped with tap-changing facilities wh ich are arranged so that the product of two o ff-nom inal settingsis unity. If the load on the system is 150 M W at 0.9 p.f. lagging, calculate the settingsof the tap changers required to maintain the voltage of the load bus at 11kV. [Use abase of 100M VA]

[10 MARK S][ C O 2 , P 0 3 , P O 4 , C 3 ]

V =230kV2=230KVt r:IFigure 4

E N D O F Q U E S T IO N P A P E R 6


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BEP 111211BEE4173ONFIDENTIAL

APPENDIX - Table of Formulas

p k)(y+Afl11)

n g

p kL..pp_p k)

VLaP,whe r eni=1 2 y j

, (k+1) = 2 ) +2 k)

11

AWR=puAPRP + QXtsV =

trlJZ

A cD

Sine cosine nd tangent of susiii(AB) s i n c o s B + cos A s in Bcos A B ) = cos A cos .8 +sinA shiBtanA tanBan A B ) =tan a n B

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Bee4173 - Power System Operation & Control