Roll No. ......................

Total No. of Questions: 08] [Total No. of Pages: 03

M.Tech.ADVANCED POWER SYSTEM ANALYSIS

SUBJECT CODE: ELE -502

Paper ID :,[E0522][Note: Please till subject code and paper ID on OMR]

Time: 03 HoursInstruction to Candidates:

1) Attempt any Five questions.2) All questions carry equal marks.

Maximum Marks: 100

01) (a) Discuss the formation of bus admittance matrix using step-by-stepmethod.

(b) A power system appears in a bridged T-network form as shown in Fig 1.formulate Y bus for the system. Values shown one admittances in thenetwork.

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Fig 1 for Q.1(b)1

VI

Q2) (a).(b)

Explain sparsity technique and optim~l ordering.Fig 2 is a 4-bus power system in which line admittances are as follows:

bus code admittance .~ 2f - 1i1-2 (2-j8) F:~ ~ .=".,f

1 ~ . ~d~21-3 (l-j4) ,-yI- t~ I-J4-

2-3 0.666 - j2.664 ~ Y ~. 4-. ~ g . :O-3rJ<'1

2-4 . 1-J4 ~o.v-rg(;-33 2-J ..-f.'3-4 2-j8 f!rb2-~ ~ 2lJ)

The schedule of active powers(P) and reactive powers (Q) is as follows:bus code P Q V bus specification

1 - - 1.06Loo slack

2 0.5 0.2 not specified PQ3 0.4 0.3 not specified PQ4 0.3 0.1 not specified PQ

form Y bus. Also compute the voltages at buses 2, 3 & 4 at the end ofIsl iteration. Use Gauss Seidel method (take ex = 1.6)

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r .~

Q3) (a)(b)

What is load flow studies and discuss Gauss-Seidel power flbW solution.Fig 3 shows I-line diagram of a simple 3-bus power system withGeneration at Bus 1. The magnitude of voltage at bus 1 is adjusted to1.05 pu. The scheduled loads at buses 2 and 3 are shown in the diagram.Line impedances are marked in pu on 100 MV A base and the linecharging susceptances are neglected.(i) Use G.S-method to obtain values of voltage at bus 2 & bus 3.(ii) Find the slack bus real and reactive power.

.i . 2 2~.6."~w

G-<>I

S/~bvJ,-o 3/Vi :: /.as!.!! ~

/ 8 f!:. c 4-::;.2-}4N J.I}{/t(f

FIG.3 ~_llfV-d/~ f&!I~

Q4) (a) Give details of Z bus - formulation for load flow solution.(b) Compare G.S, NR and Fast decoupled power flow methods of load

flow solution.

Q5) Discuss balanced three-phase fault. The single-line diagram of a simple 3-ph. power system is shown in Fig 4. Each generator is represented by anemf behind the transient reactance. impedances in pu are on a common base100 MVA with resistances neglected. The following assumptions are made(a) Shunt capacitances are neglected & system is on not load.(b) All generators are running at their rated voltages & rated frequency

with their emfs in phase obtainThe fault current, bus voltages and the line currents during the fault

when a balanced 3-ph. Fault with Zr =0.16 pu occurs on bus-3.

~

~/G4 A;.clr~'~.Sj k p.&:y.s.l-ir

~,~.2J-4033

Q6) Discuss symmetrical component analysis. of unsymmetrical faults. How isfault computation done using Z bus formulation.

Q7) Discuss state Estimation of power systems with measurements available online. How is least squares estimation gives the basic solution discuss.

Q8)Write short notes on :

(a) Improvement in state estimates by adding measurements.

(b) Algorithm formation of 3-ph Z bus.

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