Set. No:

1

Code No: NR 410203. IV-B.Tech -I-Semester Supplementary Examinations May 2004

b)

Derive the Power flow equations and therefore explain Newton Raphson method of load flow solution. Explain the terms ‘P-Q, ‘P-V’, and slack buses for a Power system and indicate their significance.

or ld

2. a)

.in

COMPUTER METHODS IN POWER SYSTEMS (Electrical and Electronics Engineering) Time: 3 hours. Max. Marks: 80 Answer any FIVE questions All questions carry equal marks --1. a) What are acceleration factors? Explain their importance in power flow studies. b) Describe load flow solution with P.V buses using G-S method.

For the network shown in fig, obtain the complex bus bar voltages at bus (2) at the end of first iteration, using Fast Decoupled method. Line impedances are in p.u. Given Bus (1) is slack bus with V1 = 1.00, P2 + jQ2 = 5.96 + j1.46 |V3| = 1.02 P3 = 2.0 p.u. Assume V2 = 10 and V3 = 1.020.

4. a)

Draw and explain how zero sequence networks are represented for 3 phase transformers with different winding connections. Briefly explain the representation of a three phase star connected neutral grounded synchronous generator in the positive, negative and zero seq networks.

nt

b)

uW

3.

Explain the bus – impedance matrix method of analysis of unsymmetrical fault. Determine the interrupting current in a circuit breaker connected to a generator rated at 20 MVA, 33 KV. Take Xd=25% and Eg=1 p.u.

6. a) b) c)

Distinguish between steady state, transient state and dynamic stability. Derive the power angle equation of a single machine connected to infinite bus. Explain the following terms (i) transfer reactance (ii) Inertia constant.

Aj

5. a) b)

(Contd…2)

Code No: NR 410203.

Set No: 1

Discuss why a) Transient stability limit is lower than steady state stability limit. b) The use of automatic reclosing circuit breakers improve system stability.

8. a) b)

What are the steps to between followed for determining multi machine stability? Write the state variable formulation of swing equations.

Aj

nt

uW

or ld

~~~~

.in

7.

.. 2 ..

Set. No:

2

Code No: NR 410203. IV-B.Tech -I-Semester Supplementary Examinations May 2004

.in

COMPUTER METHODS IN POWER SYSTEMS (Electrical and Electronics Engineering ) Time: 3 hours. Max. Marks: 80 Answer any FIVE questions All questions carry equal marks ---

Explain the load flow solution using G-S method with the help of a flow chart. How do you classify system variables in terms of state, input and output variables, in power flow studies.

2. a)

Discuss the algorithm for the Newton Raphson method for load flow solution with P.V. buses also included in the power system. Derive the necessary expressions for Jacobian matrix elements for N-R method in Polar form.

b)

Carry out one iteration of load flow solution for the system shown by Fast – Decoupled method. Take Q limits of generator 2 as Qmin = 0, Qmax = 5.

uW

3.

or ld

1.a) b)

Vspecified = 1.050. |V|specified = 1.00 p.u., PG = 3 p.u. PD = 4 p.u., QD = 2 p.u.

nt

Bus 1 slack bus Bus 2 PV bus Bus 3 PQ bus 4. a)

Aj

b)

Derive an expression to calculate the fault current phase and line voltages in a network of an unloaded generator for line to ground fault on phase “A”. Draw the connection of sequence networks for single line to ground fault through an impedance “Zf”

(Contd…2)

Code No: NR 410203.

.. 2 ..

Set No: 2

For a three phase symmetrical fault on a balanced power system using matrix notation derive the expression for (i) Current in the faulted bus (ii) Current at any other bus (iii) Voltage at any bus excluding the faulted bus b) Write the three phase representation of power system for short circuit studies and briefly explain.

.in

5. a)

Distinguish between steady state, transient state and dynamic stability. Derive the power angle equation of a single machine connected to infinite bus. Explain the following terms (i) transfer reactance (ii) Inertia constant.

7. a) b)

Discuss the methods to improve steady state and transient state stability margins. What is equal area criterion? Explain how it can be used to study stability? select any suitable example .

8.a)

Give the mathematical model for the transient stability analysis of multi machine power system. Discuss fourth-order Runge-Kutta for solving the swing equation.

uW

b)

or ld

6. a) b) c)

Aj

nt

~~~~

Set. No:

3

Code No: NR 410203. IV-B.Tech -I-Semester Supplementary Examinations May 2004

.in

COMPUTER METHODS IN POWER SYSTEMS (Electrical and Electronics Engineering ) Time: 3 hours. Max. Marks: 80 Answer any FIVE questions All questions carry equal marks --How do you classify the buses in power system and what is its necessity. Derive static load flow equations.

2. a)

Describe the Newton-Raphson method for the solution of power flow equations in power systems deriving necessary equations. What are P-V Buses? How are they handled in the above method.

b)

The figure below shows a three bus power system. Line impedances are given in p.u

uW

3.

or ld

1. a) b)

Bus 1 PQ PD = 60; QD = 25 Bus 2 PV PG = 20; PD = 50; QD = 20 Bus 3 slack V spec  1.05 0 

nt

Carry out one iteration of load flow solution by Fast-Decoupled load flow method. Discuss the effect of fault impedance on the fault current. A 3-phase, 25 MVA, 11 KV, alternator with X0=0.05 p.u, X1=X2=0.15 p.u is earthed through a reactance of 0.333 ohms. Calculate the fault current for a single line to ground fault. Derive the formulae employed.

Aj

4. a) b)

5.

Give a step by step procedure of analyzing a L-G fault on a power system by bus impedance matrix method and explain. (Contd…2)

Code No: NR 410203.

7. a) b) c) 8.

Define the following terms : i) Steady state stability limit ii) Dynamic state stability limit iii) Transient state stability limit List the assumptions made in the transient stability solution techniques. Derive the expression for steady state stability limit using ABCD parameters.

.in

b) c)

Set No: 3

Give details of assumptions made in the study of steady state and transient stability solution techniques. Give important difference between steady state, dynamic state and transient state stability studies. Give the list of methods to improve transient state stability limits.

or ld

6. a)

.. 2 ..

Describe the stability analysis of a multi machine power system and explain any one method of solving.

Aj

nt

uW

~~~~

Set. No:

4

Code No: NR 410203. IV-B.Tech -I-Semester Supplementary Examinations May 2004

.in

COMPUTER METHODS IN POWER SYSTEMS (Electrical and Electronics Engineering) Time: 3 hours. Max. Marks: 80 Answer any FIVE questions All questions carry equal marks --1. Discuss the advantages and disadvantages of finding Ybus by a) Singular transformation using graph theory. b) Directly from the network. Give illustration with necessary example.

Derive the Power balance equations in a power system and there from explain the N-R method of load flow analysis. Draw the flow chart giving the sequence of analysis. Show that the Polar Coordinate representation is advantages over the rectangular coordinates. b) Explain the advantages of using Bus Admittance matrix in load flow studies.

The sample system with the per unit impedance of lines based on 100MVA base is shown in figure. The load on bus 3 is 2.0 + j1.0, and its voltage magnitude is to be held constant at 1.0 per unit by means of the synchronous condenser at bus 2. The maximum and minimum limits of the reactive power to be supplied by the condenser is 0.5 and –0.1 respectively. With bus 1 as slack having voltage of 1.05∟0op.u. make a load - flow study using Fast – Decoupled method.

nt

uW

3.

or ld

2. a)

4. a)

Aj

b)

Derive the expression for the fault current for a line to line to ground fault. Draw the sequence network connection also. Discuss the effect of a star-delta transferma on the above fault current with fault occurring on either side of this transforma.

5.

Derive the algorithm for symmetrical short circuit analysis of a multi machine power system using Z Bus matrix. Give steps for implementing this algorithm.

(Contd…2)

Code No: NR 410203.

b) c) 7. a) b)

Define the following terms : i) Steady state stability limit ii) Dynamic state stability limit iii) Transient state stability limit List the assumptions made in the transient stability solution techniques. Derive the expression for steady state stability limit using ABCD parameters.

Discuss the general considerations and assumptions that are taken into account while studying transient stability. Discuss the various techniques adopted to improve transient stability limit.

Explain the modified Euler method of finding the stability of a multi machine system. Draw and explain the flow chart for the above method.

or ld

8.

Set No: 4

.in

6. a)

.. 2 ..

Aj

nt

uW

~~~~

Set. No Accounts

b) Derive the power angle equation of a single machine connected to infinite bus. .... 2. a) Derive the Power balance equations in a power system and there from ...

138KB Sizes 1 Downloads 275 Views

Recommend Documents

Set No. Accounts
COMPUTER GRAPHICS · (Mechatronics) ... Explain briefly about various display devices used in computer graphics. 2. a) Write an ... 2D graphics primitives.

Set No. Accounts
Code No: 220101. II B.Tech.II-Semester Supplementary Examinations, November-2003 · APPLIED ELECTRONICS · (Civil Engineering) · Time: 3 hours · Max.

Set No Accounts
Estimate residual enthalpy and residual entropy for an equimolar mixture of carbon · dioxide (1) – nitrogen (2) at 400K and 135 bar pressure by the Redlich-Kwongg .... P2, T2. If the separation is removed and the gases are mixed adiabatically.

Set No Accounts
2.a) Explain the role of display interpreter in graphical display, with a block diagram. b) What is meant by normalized device co-ordinate system? What are its ...

Set No. Accounts
MANAGERIAL ECONOMICS AND PRINCIPLES OF ACCOUNTANCY ... Technology, Electronics and Computer Engineering and Bio-Medical Engineering.).

Set No Accounts
Solve the following LPP using dynamic programming technique. Maximize Z = 10x1 + 30x2 · Subjected to 3x1 + 6x2 ≤ 168; · 12x2 ≤ 240; x1 and x2 ≥ 0. -*-*-*-.

Set No. Accounts
2.a) Will capacitance of a transmission line depend upon the ground effect? If so explain. b) Explain the ... sag, if the factor of safety is 2 and ice weighs 910kg/m.

Set No Accounts
Engineering, Computer Science and Engineering, Electronics and Instrumentation · Engineering, Bio Medical Engineering, Computer Science and Information.

Set No. Accounts
b) Explain the effect of oxygen on radio sensitivity of the tumor cell. 6. a) Describe the ... Explain the Modalities of radiation therapy. 6. Explain the radiation ...

Set No. Accounts
Himalayan Orchards have canned apple and bottled juice as its product with profit ... following table gives the expected annual sales ( in thousands of Rs.) for ...

Set No Accounts
exonuclease activity, initiator protein, helicase, topoisomerase. 3. Write the differences between the eukaryotic and prokaryotic RNA polymerases · and their ...

Set No Accounts
d) In many factories, the smoke before it comes out from the chimney is led over · charged metallic plates. 7.a) What is meant by equivalent and molar ...

Set No. Accounts
What do you understand by 'Marketing mix' and what components influence the · marketing process? 7.a) Write a short note on CPM. b) What is the difference ...

Set No. Accounts
layer and transport layer. b) Map TCP/IP Protocol suite onto the layers of the OSI model. ... 3. a) What is the frame format of HDLC protocol. What are operational ...

Set No Accounts
and exposed to still air at 25°C. If the pipe wall temperature is 295°C, · determine the rate of heat loss. .... expression for the same. b) Air at 25°C flows normally to 0.03m outer diameter water pipe with a velocity .... 0.04 kg/s of 34°API cr

Set No Accounts
a) Recorder b) Instrumentation diagrams c) Refractometer d) McLeod gage. - - - ... Explain the construction and working of the McLeod gage and the Pirani gage.

Set No. Accounts
EEG, EMG and ERG signals. 2.a) Draw the heart pump diagram. Explain how it pumps blood to all the body parts. b) Explain how Bioelectric potentials are ...

Set No Accounts
8.a) Explain the database Recovery Technique based on Deferred Update. b) What are the roles of Analysis, Redo and Undo phases in ARIES? ^^^. Set No.

Set No. Accounts
Science and Engineering, Chemical Engineering, Computer Science and Information · Technology .... kept in mind for drawing network? 8. The following ...

Set No. Accounts
c) Give a brief note on prosthetic heart valves. 8. Describe the mechanical properties of bone with examples. Explain what do you · understand by Lubrication of ...

Set No Accounts
Obtain an expression for the steady state Equimolal counter diffusion of two gases ... 1. a) Write the fick's law of diffusion for 'Z' direction. What is the significance ...

Set No Accounts
Crack in the metal · (ii) · Wire fence. (iii) Rivetted joints. b) What is meant by phosphating of steel? 4.a) Distinguish between thermoplastics and thermosetting ...

Set No. Accounts
c) What is etching? Explain with neat sketches. d) Draw a neat sketch of metallurgical microscope and explain various parts of it. 2.a) Draw neat sketches of 3 ...

Set No Accounts
Write an account of Hodgekin-Huxley equation and add a note on its biological · relevance. Explain the terms- Membrane time constant and space constant.