ENUGU STATE UNIVERSITY OF SCIENCE AND TECHNOLOGY ESUT
DEPARTMENT OF ELECTRICAL/ELECTRONICS ENGINEERING
SECOND SEMESTER EXAMINATION 2011/2012 SESSION
ELECTRICAL POWER SYSTEMS ANALYSIS II. (EEE 554)
TIME: 1Hr 30Min (Answer All Questions)
NB: IF you have not done any continuous assessment, write down what you have learnt in about 120 words first.
Basic Concept
What is
modeling? Why is it important in Electrical Power Systems Analysis? What is the
relevance of Fault Analysis in Power System Protection Scheme design? Develop
the Model of a long line. Develop the Model of a transformer. How does a synchronous
generator work? Develop the model of a synchronous generator. What is a phasor?
What is a passive load? What is the relevance of Symmetrical Components in
Electrical Power Systems Analysis? Explain with the help of appropriate
diagrams, the analysis of a single line to ground fault. What is state
estimation? How are errors accounted for in State Estimation in Electrical
Power Systems Analysis? What is Stability Studies. Explain the concept of First
Swing and Multi-Swing Stability Studies. Develop an expression for the swing equation
for stability studies? What is this Swing equation? What is a Bus? Under what
condition would a voltage controlled Bus revert to a Load Bus in the course of
an analysis? Explain your answer. Develop the Newton Raphson iterative method
for Load flow analysis. Explain this procedure. Explain the concept of Single
line diagram. Explain the concept of Per Unit System in Electrical Power
Systems Analysis.
Application
Security is a
Problem in the country at the moment. How would you use any of the Electrical
Power Systems Engineering Analytical tools to improve the security situation in
the country? How would you carry out this exercise? Show the correlation
between your work and the anticipated improvement in the security situation.
Load flow analysis is important in the management of the Electrical Power
System. How can this be applied in system management, planning and contingency
provision in the Electrical Power System? Consider other similar situations
that would benefit from a similar algorithm. What are transmission line
Parameters derive an expression for any two of them. Outline the state
Estimation procedure. Explain your work with the aid of block diagram of flow
chart or both or as well as a signal flow chart. What is the efficiency of an
ideal transformer and why?
Calculation
Compare the
Newton Raphson iterative method and the Gauss Seidel iterative method for Load
Flow analysis. What is acceleration factor? How is it determined, and what is
it used for? In an iterative analysis, how would you know that convergence has
occurred? Outline the procedure for fault Analysis. Derive an expression for
calculating the Symmetrical Components of a given set of three phase phasors.
The
transmission line in the figure below is 200km long and a 132kV line of the
phase symmetric type. Given the data below, determine the voltage at Bus 2 given
that R = 0.87 Ω/km, ωL=0.457Ω/km, 1/ωC = 0.525MΩ/km
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Name: Nwani Ikechukwu Destiny
ReplyDeleteReg No: Esut/2008/94377
Course: Electrical Power System Analysis (EEE454)
An unbalanced system of N related phasor can be resolved into N system of balanced phasor called symetrical phasor component of the regional phasor. These are equal in length and the distance between them. In electrical power system we have three symetrical components:
1. Positive - sequence component
2. Negative – sequence component
3. Zero – sequence component
Notation
+ve positive sequence component 1
-ve negative sequence component 2
Zero zero sequence component 0
Va = va1 + va2 + va0
Vb = vb1 +vb2 + vb0
Vc = vc1 + vc2 + vc0
Phasor is a vectoral representation of mathematically abstract components but phase represents the three winding lines that make a current. E. g. Red, Yellow, Blue. Etc
Per unit system is a means of normallizing the dimension of electrical quantities
Per unit value=actual value , Vbase Ibase =Sbase
Base value
Modelling is the mathematical representation of electrical quantities.
Assuming infinite conductivity and permeability hence no resistance and no flux leakage.
V1= N1dØ/dt
V2= N2dØ/dt
V3= N3dØ/dt
NAME:UZUAKPUNDU MICHAEL.C
ReplyDeleteREG NO:ESUT/2011/110407
COURSE:EEE341
when two masses or charges are @ stationary the force between them is inversely proportional to their square of their distance between them(law of electrostatics)
MACHANICS..is the theory that describes the behaviour of an object under the action of an unknown force.
directional derivatives :is the rate of change in a particular direction
POSITION VECTOR:it is the vector describing a position
AMPERE LAW:if a current carrying wire posses a certain symerty the magnetic field can be obtain by using AMPERE LAW
A VECTOR :is a directed line segment it has both length and direction.the length is called the direction of the vector two vectors are equal if and only if they hav the same length and diection.the length of a vector is called the EUCLIDEAN NORM
NAME:UZUAKPUNDU MICAEL
ReplyDeleteREG NO:ESUT/2011/110407
DEPT:ELECTRICAL ELECTRONIC ENGINEERING
COURSE:EEE341(ELECTROMAGNETIC FIELD AND WAVE)
MACHANICS:this is the theory that describes the behavior of an object under the action of a known force.
LAW OF ELECTROSTATICS :when two masses or charges are stationary,the force between then is iversly proportional to their square of their separation and the distance between them.
EUCLIDEAN NORM:two vectors are equal if and only if they have the same length and direction.
AMPERE LAW:if a current carrying wire posses a certain symmetry the magnetic field can be obtain by using AMPERE LAW
A VECTOR is a directional line segment it has both length and direction the length is called the length of the vector and direction is called the direction of the vector.
COLUMBS LAW:like charges repel and unlike charges attracts(2)the force is propotional to magnitude of each charge(3)the force is inversely proportional to the square of the distance between them
DIRECTIONAL DERIVATIVES:it is the rate of change in a particular direction
POSITION VECTOR:It is the vector describing a position
NAME: MBAEZE CHIDERA JUDE
ReplyDeleteREG NO: ESUT/2013/146381
DEPARTMENT: ELECTRICAL ELECTRONICS ENGINEERING
COURSE: ELECTRICAL POWER SYSTEM ANALYSIS II (EEE 554)
THESE ARE WHAT I HAVE LEARNT.
STABILITY STUDIES: This is the ability to know if a system will retain its synchronism after perturbation (disturbance) and this can be classified into Transient, Dynamic and Steady state. Although under normal circumstances a system is considered to be QUAZISTATIC which means the system can change continually.
FIRST SWING STABILITY STUDIES: This is based on reasonable simple generator model without a representation of control system. Usually a time period under study is the first second following a system fault. If the machines of the system are found to remain in synchronism within the first second, the machine is said to be steady.
MULTI-SWING STABILITY STUDIES: Problem extends over a longer period and therefore must consider effect of the generator control system which affects machine performance during the extended time period.
SWING EQUATION: This is simply the equation that determines the stability status of the electric power system.
PHASOR: This can be said to be a representation of electrical quantities using vector which is the quantity that has both magnitude and direction. MMF = NI Produce a field flux either by a permanent magnet or current carrying conductor.
SYMMETRICAL COMPONENTS: These are a set of balanced phasor which can be used to represent or resolve an unbalanced system of n related phasor into n system of balanced phasors. This can be classified into types, Positive, Negative and Zero sequence components.
LOAD FLOW ANALYSIS: this is the study of the power system with the view of knowing the voltage at the various buses using system configuration, loading at each bus, system topology and system parameters.
FAULT ANALYSIS: Is a study of power system after a fault with a view of finding the voltage and the current distribution subsequently. It can also be used to protect scheme design.
BUS: This is a connection point in in an electrical power system circuit, while GRID can be said to be a bus.
STATE ESTIMATION: This is a study of electrical power system with the view of determining the state of the system at any given time using variables which may or may not be measurable, observable or accessible.
POWER MISMATCH: This is the difference between the measured power and calculated power.
A PHASE: Is as a result of how the alternating current is produced from a synchronous machine, the a.c is produced in a synchronous machine EMF is induced in three winding stator of the synchronous generator.
CRITICAL CLEARING ANGLE: Is the angle beyond which a fault is cleared, hereby the system does not return to synchronism.
LONG LINE: is a line that is more than 240km L > 240km.
MODELING: This is a mathematical representation of electrical quantities.
PASSIVE LOAD: This is a load that consist of only resistors, capacitors or inductors or all of the combined. only sequence load that is active or that is positive or that has source or battery.