Introduction and First Lecture
ECE 633 MODELING AND SIMULATION OF POWER
SYSTEM COMPONENTS
August 23, 2005
Oleg Wasynczuk
Contact Information
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Oleg Wasynczuk
1285 Electrical Engineering
Purdue University
West Lafayette, IN 47907-1285
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Office/Lab: 765 494-3475
Lab EE58
wasynczu@ecn.purdue.edu
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Include ECE633 in subject line
http://shay.ecn.purdue.edu/~wasynczu
Computer Requirements
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Ready access to computer with
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Simulink Version 6 (R14)* – preferred
Simulink Version 5 (R13) - acceptable
Ability to email compressed folders
containing reports and Simulink models
(.doc, .pdf, and .mdl files)
* We will not use any of the many optional
toolboxes
Questionnaire – email before Session 2
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Name, major, degree objective, expected date of
graduation
Degree of familiarity with (a) Matlab, (b) Simulink
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1 - no clue, 2- ketbd, 3-basics, 4-adept, 5-expert
Other simulation languages you use and degree of
familiarity
Thesis topic (if known), current research and/or job
related projects, description of technical interests,…
Course expectations
Grading
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70% Approximately 10 Simulink-based projects
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Late work will be penalized at 20% per day unless
prior arrangements are made
15% Midterm
15% Final
Cheating Policy
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You may discuss projects, including
results, with fellow students; however,
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Sharing of models is not permitted
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No two people should have the same models
Report must be your own thoughts and
words
First occurrence results in stern warning
Second occurrence results in non-passing
grade for course
Office/Lab Hours (EE58)
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Tuesday/Thursday 1:30-3:30 pm
(tentative)
Pre- or Co-requisites by Subject
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Pre-requisite
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Co-requisite
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Junior or senior course in electric machinery
and/or power systems such as ECE 321,
425, or 432
Graduate course in energy conversion such
as ECE 610
Please let me know if you have
questions/concerns
Course Outline
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Will follow spirit of published course
outline (see web site)
Major topics to be covered include:
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Distributed- and lumped-parameter models
of transmission lines
Single- and three-phase transformers
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Magnetic saturation
Induction machines (and drives)
Synchronous machines (and drives)
Required Text
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Chee-Mun Ong, Dynamic Simulation of
Electric Machinery Using Matlab Simulink,
Prentice Hall, 1998, ISBN 0-13-723785-5.
First Reading Assignment
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Read Chapters 1 and 2 before Session 2
Modeling Philosophy for Dynamic Simulation
of Power System Components
Modeling Versus Simulation
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Modeling
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Expression of relevant physical principles in
mathematical form (PDE’s, ODE’s, AE’s,
circuit/block diagrams) along with pertinent
initial/boundary conditions
Simulation
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Application of suitable numerical algorithms to
generate numerical solution to set of models
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Always an approximation (round-off, truncation
errors)
Synchronous Machine Models
Distributed Parameter
Coupled Circuit
Steady State
Z  R  jX


Ee
j
~
I

~
V

dx
 f (x, u)
dt
~
~
V  Ee j  ZI
Power Electronic Models
Detailed
dxi
 f ( xi , si ); xi (t0i )  Tx i 1 (t fi 1 )
dt
(t fi , si 1 )  g ( xi , si )
Average Value
dx
 f (x, u)
dt
Simulation Approaches
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Finite-Element-Based Approaches (Ansys,
Maxwell, …)
Circuit-Based Approaches (Spice, EMTP, Saber,
PSIM, Simplorer)
System-Based Approaches (Simulink, ACSL,
Dymola)
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Block-diagram and/or differential equation oriented
Extensive set of tool boxes including
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ASMG (Simulink, ACSL)
Power System Blockset (Simulink)
…
Finite-Element Based Approaches
FEA
M
4000-10000 Nodes
da
 Sa  u
dt
Simulation Approaches
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Finite-Element-Based Approaches (Ansys,
Maxwell, …)
Circuit-Based Approaches (Spice, EMTP,
Saber, PSIM, Simplorer)
System-Based Approaches (Simulink, ACSL,
Dymola)
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Block-diagram and/or differential equation oriented
Extensive set of tool boxes including
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ASMG (Simulink, ACSL)
Power System Blockset (Simulink)
…
Circuit-Based Approaches
Circuit-Based Approaches
Example Subsystem (Motor Controller)
Circuit-Based Approaches
Circuit-Based Approaches
Resistor-Companion Circuit
Circuit-Based Approaches
Update Formula
 iS   g1  g 2  g 3  g S
 i  

 S 
 i7   

 
i
 8  
 i9  
 gS
g 4  g5  g6
 g1  g 2


 g 3  v1 
  v2 
  
 
 
 v5 
k 1
O(n3) computational complexity where n =
number of non-datum nodes
Simulation Approaches

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Finite-Element-Based Approaches (Ansys,
Maxwell, …)
Circuit-Based Approaches (Spice, Saber, PSIM,
Simplorer)
System-Based Approaches (Simulink, ACSL,
Dymola)

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Block-diagram and/or differential equation oriented
Extensive set of tool boxes including
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ASMG (Simlink, ACSL)
Power System Blockset (Simulink)
PLEX (Simulink)
…
System-Based Approaches
Hierarchical system definition
System-Based Approaches
Common Simulink Component Models
System-Based Approaches
System-Based Approaches
When user starts model, Simulink applies selected
integration algorithm to approximate solution at
discrete but not necessarily uniform instants of time
General Multi-step Update Formula:
x
k 1
p 1
  i x
i 0
k i
p 1

 h  i f x k i , t k i
i  1

Explicit if 1  0
Implicit algorithms require solution of nonlinear
equation (dimension = number of states) at each
time step. Newton-Raphson iteration generally
used.
System-Based Approaches
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Choice of coefficients determines name of
algorithm
Many different algorithms out there
See Appendix A for brief introduction
System-Based Approaches
Stiff System: A system with both fast and slow
dynamics
Stiffly Stable Integration Algorithm: the ability to
increase the time step after fast transients subside
Stiffly Stable Algorithms are implicit!
System-Based Approaches
Computational Complexity
System-Based Approaches
System-Based Approaches
Simulink Fixed-Step Algorithms
Shampine and Reichelt, The MATLAB ODE Suite, SIAM J. Sci. Comput.,
Vol. 18, No. 1, pp. 1-22, January 1997.
System-Based Approaches
Simulink Variable-Step Algorithms
Shampine and Reichelt, The MATLAB ODE Suite, SIAM J. Sci. Comput.,
Vol. 18, No. 1, pp. 1-22, January 1997.
Simulation Approaches (Conclusion)
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Co-simulation
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Finite Element/Circuit
Circuit/System
Distributed Heterogeneous Simulation
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Any combination of the above mentioned
approaches