EE2404 POWER SYSTEM SIMULATION LABORATORY L T P C
0 0 3 2
To acquire software development skills and experience in the usage of standard packages
necessary for analysis and simulation of power system required for its planning, operation and
i. To develop simple C programs for the following basic requirements:
a) Formation of bus admittance and impedance matrices and network solution.
b) Power flow solution of small systems using simple method, Gauss-Seidel P.F.
c) Unit Commitment and Economic Dispatch.
II. To acquire experience in the usage of standard packages for the following
analysis / simulation / control functions.
d) Steady-state analysis of large system using NRPF and FDPF methods.
e) Quasi steady-state (Fault) analysis for balanced and unbalanced faults.
f) Transient stability simulation of multimachine power system.
g) Simulation of Load-Frequency Dynamics and control of power system.
1. Computation of Parameters and Modelling of Transmission Lines
2. Formation of Bus Admittance and Impedance Matrices and Solution of Networks.
3. Load Flow Analysis - I : Solution of Load Flow And Related Problems Using
4. Load Flow Analysis - II: Solution of Load Flow and Related Problems Using Newton-
Raphson and Fast-Decoupled Methods
5. Fault Analysis
6. Transient and Small Signal Stability Analysis: Single-Machine Infinite Bus System
7. Transient Stability Analysis of Multimachine Power Systems
8. Electromagnetic Transients in Power Systems
9. Load – Frequency Dynamics of Single- Area and Two-Area Power Systems
10. Economic Dispatch in Power Systems.
TOTAL : 45 PERIODS
1. COMPUTATION OF PARAMETERS AND MODELLING OF TRANSMISSION
(i) To determine the positive sequence line parameters L and C per phase per kilometer of a
three phase single and double circuit transmission lines for different conductor
(ii) To understand modelling and performance of short, medium and long lines.
Computation of series inductance and shunt capacitance per phase per km of a three phase line
with flat horizontal spacing for single stranded and bundle conductor configuration.
Computation of series inductance and shunt capacitance per phase per km of a three phase
double circuit transmission line with vertical conductor arrangement with bundle conductor.
Computation of voltage, current, power factor, regulation and efficiency at the receiving end of a
three phase Transmission line when the voltage and power at the sending end are given. Use П
Computation of receiving end voltage of a long transmission for a given sending end voltage and
when the line is open circuited at receiving. Also compute the shunt reactor compensation to
limit the no load receiving end voltage to specified value.
Determination of the voltage profile along the long transmission line for the following cases of
loading at receiving end (i) no load (ii) rated load (iii) surge impedance loading and (iv) receiving
end short circuited.
2. FORMATION OF BUS ADMITTANCE AND IMPEDANCE MATRICES AND SOLUTION OF
To understand the formation of network matrices, the bus admittance matrix Y and the bus
impedance matrix Z of a power network, to effect certain required changes on these matrices and to
obtain network solution using these matrices.
2.1 Write a program in C language for formation of bus admittance matrix Y of a power network
using the “Two-Rule Method”, given the data pertaining to the transmission lines, transformers
and shunt elements. Run the program for a sample 6 bus system and compare the results with
that obtained using a standard software.
2.2 Modify the program developed in 2.1 for the following:
(i) To obtain modified Y matrix for the outage of a transmission line, a
Transformer and a shunt element.
(ii) To obtain network solution V given the current injection vector I
(iii) To obtain full Z matrix or certain specified columns of Z matrix.
Verify the correctness of the modified program using 6 bus sample system
* 2.3 Write a program in C language for forming bus impedance matrix Z using
the “Building Algorithm”.
* Optional (not mandatory)
LOAD FLOW ANALYSIS - I : SOLUTION OF LOAD FLOW AND RELATED PROBLEMS USING
(i) To understand, the basic aspects of steady state analysis of power systems that are
required for effective planning and operation of power systems.
(ii)To understand, in particular, the mathematical formulation of load flow model in complex form
and a simple method of solving load flow problems of small sized system using Gauss-Seidel
3.1 Write a program in c language for iteratively solving load flow equations using
Gauss-Seidel method with provision for acceleration factor and for dealing
with P-V buses. Run the program for a sample 6 bus system (Base case)
and compare the results with that obtained using a standard software.
3.2 Solve the “Base case” in 3.1 for different values of acceleration factor, draw the convergence
characteristics “Iteration taken for convergence versus acceleration factor” and determine the
best acceleration factor for the system under study.
3.3 Solve the “Base Case” in 3.1 for the following changed conditions and comment on the results
obtained, namely voltage magnitude of the load buses and transmission losses:
(i) Dropping all shunt capacitors connected to network
(ii) Changing the voltage setting of generators Vgi over the range 1.00 to 1.05
(iii) Changing the tap setting of the transformers, ai, over the range 0.85 to 1.1
3.4 Resolve the base case in 3.1 after shifting generation from one generator bus to another
generator bus and comment on the MW loading of lines and transformers.
4. LOAD FLOW ANALYSIS – I: SOLUTION OF LOAD FLOW AND RELATED
PROBLEMS USING NEWTON-RAPHSON AND FAST DECOUPLED
(i) To understand the following for medium and large scale power systems:
(a) Mathematical formulation of the load flow problem in real variable form
(b) Newton-Raphson method of load flow (NRLF) solution
(c) Fast Decoupled method of load flow (FDLF) solution
(ii) To become proficient in the usage of software for practical problem solving in the areas of
power system planning and operation.
(iii) To become proficient in the usage of the software in solving problems using Newton-
Raphson and Fast Decoupled load flow methods.
4.1 Solve the load flow problem (Base case) of a sample 6 bus system using Gauss-Seidel, Fast
Decoupled and Newton-Raphson Load Flow programs for a mismatch convergence tolerance of
0.01 MW, plot the convergence characteristics and compare the convergence rate of the three
4.2 Obtain an optimal (minimum transmission loss) load flow solution for the Base case loading of 6
bus sample system by trial and error approach through repeated load flow solutions using Fast
Decoupled Load Flow package for different combinations of generator voltage settings,
transformer tap settings, and reactive power of shunt elements.
4.3 Carry out contingency analysis on the optimal state obtained in 4.2 for outage of a transmission
line using FDLF or NRLF package.
4.4 Obtain load flow solutions using FDLF or NRLF package on the optimal state obtained in 4.2 but
with reduced power factor (increased Q load) load and comment on the system voltage profile
and transmission loss.
4.5 Determine the maximum loadability of a 2 bus system using analytical solution as well as
numerical solution using FDLF package. Draw the P-V curve of the system.
4.6 For the base case operating state of the 6 bus system in 4.1 draw the P-V curve for the weakest
load bus. Also obtain the voltage Stability Margin (MW Index) at different operating states of the
4.7 For the optimal operating state of 6 bus system obtained in 4.2 determine the
Available Transfer Capability (ATC) between a given “source bus” and a given “s
4. FAULT ANALYSIS
To become familiar with modelling and analysis of power systems under faulted condition and to
compute the fault level, post-fault voltages and currents for different types of faults, both
symmetric and unsymmetric.
5.1 Calculate the fault current, post fault voltage and fault current through the branches for a three
phase to ground fault in a small power system and also study the effect of neighbouring system.
Check the results using available software.
5.2 Obtain the fault current, fault MVA, Post-fault bus voltages and fault current distribution for single
line to ground fault, line-to-line fault and double line to ground fault for a small power system,
using the available software. Also check the fault current and fault MVA by hand calculation.
5.3 Carryout fault analysis for a sample power system for LLLG, LG, LL and LLG faults and prepare
6. TRANSIENT AND SMALL-SIGNAL STABILITY ANALYSIS: SINGLE
MACHINE-INFINITE BUS SYSTEM
To become familiar with various aspects of the transient and small signal stability analysis of Single-
Machine Infinite Bus (SMIB) system.
For a typical power system comprising a generating, step-up transformer, double-circuit transmission
line connected to infinite bus:
Transient Stability Analysis
6.1 Hand calculation of the initial conditions necessary for the classical model of the
6.2 Hand computation of critical clearing angle and time for the fault using equal area
6.3 Simulation of typical disturbance sequence: fault application, fault clearance by opening of one
circuit using the software available and checking stability by plotting the swing curve.
6.4 Determination of critical clearing angle and time for the above fault sequence through trial and
error method using the software and checking with the hand computed value.
6.5 Repetition of the above for different fault locations and assessing the fault severity with respect
to the location of fault
6.6 Determination of the steady-state and transient stability margins.
Small-signal Stability Analysis:
6.7 Familiarity with linearised swing equation and characteristic equation and its roots,
damped frequency of oscillation in Hz, damping ratio and undamped natural
6.8 Force-free time response for an initial condition using the available software.
6.9 Effect of positive, negative and zero damping.
7. TRANSIENT STABILITY ANALYSIS OF MULTIMACHINE POWER SYSTEMS
To become familiar with modelling aspects of synchronous machines and network, state-of-the-art
algorithm for simplified transient stability simulation, system behaviour when subjected to large
disturbances in the presence of synchronous machine controllers and to become proficient in the
usage of the software to tackle real life problems encountered in the areas of power system planning
For typical multi-machine power system:
7.1 Simulation of typical disturbance sequence: fault application, fault clearance by opening of a
line using the software available and assessing stability with and without controllers.
7.2 Determination of critical clearing angle and time for the above fault sequence through trial
and error method using the software.
7.3 Determination of transient stability margins.
7.4 Simulation of full load rejection with and without governor.
7.5 Simulation of loss of generation with and without governor.
7.6 Simulation of loss of excitation (optional).
7.7 Simulation of under frequency load shedding scheme (optional).
8. ELECTROMAGNETIC TRANSIENTS IN POWER SYSTEMS
To study and understand the electromagnetic transient phenomena in power systems caused due to
switching and faults by using Electromagnetic Transients Program (EMTP) and to become proficient
in the usage of EMTP to address problems in the areas of over voltage protection and mitigation
and insulation coordination of EHV systems.
Using the EMTP software or equivalent
Simulation of single-phase energisation of the load through single-phase pi-model of a transmission
line and understanding the effect of source inductance.
8.1 Simulation of three-phase energisation of the load through three-phase pi-model of a
transmission line and understanding the effect of pole discrepancy of a circuit breaker.
8.2 Simulation of energisation of an open-ended single-phase distributed parameter transmission
line and understanding the travelling wave effects.
8.3 Simulation of a three-phase load energisation through a three-phase distributed parameter
line with simultaneous and asynchronous closing of circuit breaker and studying the effects.
8.4 Study of transients due to single line-to-ground fault.
8.5 Computation of transient recovery voltage.
9. LOAD-FREQUENCY DYNAMICS OF SINGLE-AREA AND TWOAREA
To become familiar with the modelling and analysis of load-frequency and tie-line flow dynamics of a
power system with load-frequency controller (LFC) under different control modes and to design
improved controllers to obtain the best system response.
9.1 Given the data for a Single-Area power system, simulate the load-frequency dynamics (only
governor control) of this area for a step load disturbance of small magnitude, plot the time
response of frequency deviation and the corresponding change in turbine power. Check the
value of steady state frequency deviation obtained from simulation with that obtained by hand
9.2 Carry out the simulation of load-frequency dynamics of the Single-Area power system in 9.1
with Load-frequency controller (Integral controller) for different values of KI (gain of the
controller) and choose the best value of KI to give an “optimal” response with regard to peak
over shoot, settling time, steady-state error and Mean-Sum-Squared-Error. [
9.3 Given the data for a two-area (identical areas) power system, simulate the load-frequency
dynamics (only governor control) of this system for a step load disturbance in one area and
plot time response of frequency deviation, turbine power deviation and tie-line power deviation.
Compare the steady-state frequency deviation obtained with that obtained in the case of
9.4 Carry out the simulation of load-frequency dynamics of two-area system in 9.3 for the following
(i) Flat tie-line control
(ii) Flat frequency control
(iii) Frequency bias tie-line control
and for the frequency bias Tie-line control mode, determine the optimal values of
gain and frequency bias factor required to get the “best” time response.
9.5 Given the data for a two-area (unequal areas) power system, determine the best controller
parameters; gains and bias factors to give an optimal response for frequency deviation and tieline
deviations with regard to peak overshoot, settling time, steady-state error and Mean-
10. ECONOMIC DISPATCH IN POWER SYSTEMS
(i) To understand the basics of the problem of Economic Dispatch (ED) of optimally
adjusting the generation schedules of thermal generating units to meet the system
load which are required for unit commitment and economic operation of power
(ii) To understand the development of coordination equations (the mathematical model
for ED) without and with losses and operating constraints and solution of these
equations using direct and iterative methods
10.1. Write a program in ‘C’ language to solve economic dispatch problem of a power system
with only thermal units. Take production cost function as quadratic and neglect
10.2. Write a program in ‘C’ language to solve economic dispatch problem of a power system.
Take production cost as quadratic and include transmission loss using loss co-efficient.
Use λ-iteration algorithm for solving the co-ordination equations.
10.3. Determine using the program developed in exercise 10.1 the economic generation
schedule of each unit and incremental cost of received power for a sample power system,
for a given load cycle.
10.4. Determine using the program developed in exercise 10.2 the economic generation
schedule of each unit, incremental cost of received power and transmission loss for a
sample system, for the given load levels.
10.5. Apply the software module developed in 10.1 to obtain an optimum unit commitment
schedule for a few load levels.
REQUIREMENT FOR A BATCH OF 30 STUDENTS
S.No. Description of Equipment Quantity
1. Personal computers (Pentium-IV, 80GB, 512
2. Printer laser 1
3. Dotmatrix 1
4. Server (Pentium IV, 80GB, 1GBRAM) (High
5. Software: E.M.T.P/ETAP/CYME/MIPOWER
/any power system simulation software
6. Compliers: C, C++, VB, VC++ 25 users