COURSE OUTLINE Fall 2010

COURSE OUTLINE

Fall 2010


1. Calendar Information

Electrical Engineering
5
8
5

Introduction to Power Electronics

Commutation. Diode rectifiers. Fully controlled 3
-
phase rectifiers. Choppers, inverters,
ac controllers. Single
-
phase switch mode converters: dc
-
to
-
dc, ac
-
to
-
dc, dc
-
to
-
ac
. Circuit
and state
-
space averaging techniques. Switching devices and magnetics.


Course Hours:

H(3
-
2/2)

Calendar Reference:

http://www.ucalgary.ca/pubs/calendar/current/
electrical
-
engineering.html#7645

2. Learning Outcomes


In this course we will rev
iew then we will investigate
further
the following concepts:
power balance, averaging, root mean square, orthogonality, commutation, and
most
especially
the definition of inductance expressed as
v

dt

=

L

di
, with its many
interpretations: as a definite int
egral used for commutation interval calculation; as a
difference equation used for current ripple calculation (for one state of a converter in a
time interval approximated by dt); in AC steady
-
state analysis giving an average inductor
voltage of zero and g
iving us the principle of Volt second balance; in DC steady
-
state (ie,
with a constant value of average inductor current) once again giving an average inductor
voltage of zero and once again giving us the principle of Volt second balance but this
time appl
ied to DC; as a time
-
scale independent form, namely,
v

d
θ

=

ω
L

di

allowing
average and rms calculations for any period of the cycle; in Laplace form, V

=

I

ω
L


permitting

ripple current approximations; and
in Laplace
-
Fourier form, V
=
I

h
ω
L


giving us
current amplitude calculations at each harmonic frequency
. Al
l t
hese concepts will then
be employed in the time
-
domain
steady
-
state
analysis of several power converters.


With an emphasis on steady
-
state operation

(though we need to know that power
-
up
and other transients are also considered as well in converter

design practice)
, we will
study three classes of non
-
linear, or switching, power converters, namely: (a) Diode
Based Power Converter Topologies, where we will investigate low
-
power (ie, below
1.5kW) single
-
phase diode rectifiers as well as the high power
full
-
bridge 3
-
phase diode
rectifier that is employed in kilo
-
Watt to mega
-
Watt applications; (b) Thyristor Based
Power Converter Topologies, where several types of conventional high power converters
will be examined, including the fully
-
controlled 3
-
phase
rectifier, the dc chopper, the six
-
step 3
-
phase inverter (with a little bit of frequency domain analysis), and the single
-
phase ac controller; and

(c)

Transistor Based Power Converter Topologies, sometimes
called switch mode converters, that have proven th
emselves at sub
-
kilowatt power levels
and are becoming popular at higher power levels up to mega
-
Watts. The three basic
switch mode converters that we will study in the context of low power applications are
the buck, boost and inverting converters. We will

also study two isolated types of switch
mode converters, namely, the hybrid
-
bridge forward converter and the flyback converter.


Our main scholastic objective
s of this course are two fold: (1) To be able to sketch
steady
-
state waveforms for the most com
mon industrial and commercial power
converters. We will have lots of practice using our KVL (Kirchhoff Voltage Law) and
KCL (Kirchhoff Current Law) circuit analysis skills; and (2) To know which inductor
interpretation to use, dependant upon the objectiv
e of our analysis, e.g. to find peak
-
to
-
peak current ripple in a DC chopper: for high ripple (we will determine in this course what
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ENEL585
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“high” means) we use the differential equation, but for low ripple we use the difference
equation form. In each case we will

select the calculation method that is the most
succinct
–

a skill that is particularly useful when performing original design work.

At the end of this course (where each point below is taken from each chapter of our
course notes at http://www2.enel.ucalga
ry.ca/People/Nowicki/), you will be able to:




distinguish between linear and non
-
linear power converter operation



recognize when commutation takes place and calculate the commutation period



use the principle of power balance as a check on your circuit anal
ysis



perform quick “back of the envelope” average and rms calculations and apply the
principle of othogonality to aid you in your rms calculations; to know that the
terms “average” and “DC” are interchangeable in the context of power converters



for diode r
ectifiers: sketch steady
-
state waveforms; calculate the average output
voltage and input power factor, without and with the inclusion of line inductance;
and also estimate output current ripple for inductive loads using an approximate
“effective ripple imp
edance”



for SCR rectifiers: sketch steady
-
state waveforms; calculate the average output
voltage and input power factor, as a function of the firing angle, without and with
the inclusion of line inductance; estimate the commutation interval with an
approxim
ate commutation inductor voltage



for DC choppers: sketch steady
-
state waveforms including a piece
-
wise
approximation when the current ripple is less than 50%; calculate the average
output voltage by applying KVL to averaged element voltages; estimate outpu
t
current ripple for each state of the converter from the definition of inductance
expressed as
v

dt

=

L

di



for the 3
-
phase SCR Voltage Source Inverter: sketch steady
-
state waveforms for
LR loads; estimate the current ripple using Fourier analysis



for the
single
-
phase AC Controller: sketch steady
-
state waveforms for LR loads
in discontinuous and continuous current modes; and to know which mode the
controller is operating in



for buck, boost and inverting DC
-
to
-
DC converters: sketch steady
-
state
waveforms; de
termine the DC input to output voltage transfer function using the
principle of Volt second balance (a direct consequence of an inductance in DC
steady
-
state); determine the boundary condition, if any, between continuous and
discontinuous mode; be able to
estimate the output voltage ripple from the
definition of capacitance expressed as
i

dt

=

C

dv

(in direct analogy with current
ripple calculations for inductance)



for the transformer isolated Forward and Flyback DC
-
to
-
DC converters: sketch
steady
-
state wav
eforms; be able to invent/synthesize these converters starting
with a buck or inverting converter and thus determine the DC input to output
voltage transfer function by extension; determine the DC input to output voltage
transfer function using the princip
le of Volt second balance; and to know which
parameters of a transformer have the greatest effect on converter operation.

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ENEL585
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3. Timetable

Section

Days of the
Week

Start

Time

Duration

(Minutes)

Location

L01

MWF

12:00

50

SB 146

B01

F

10:00

110

ENA 0
6

B02

F

1
0:00

110

ENA 0
6

4. Course Instructors

Course
Instruc
tor

Section

Name

Phone

Office

Email

L01, B01
-
02

E. Nowicki

(403) 220
-
5006

ENA 206F

enowicki@ucalgary.ca


Teaching Assistants

Section

Name

Phone

Office

Email

B01
-
02

Arif Al
-
Judi

403
-
891
-
3406

ENA206D

a
rifaljudi@gmail.com

B01
-
02

Nacer Benaifa

403
-
660
-
4707

ENA206D

nacer.benaifa@gmail.com


5. Examinations

The following
examinations will

be held in this course:



6 In
-
class Quizzes
: closed book, closed notes
; best 4 counted for grading purposes



In
-
class Mid
term: closed book, closed notes



Final

exam
: 3 hours, Registrar scheduled (closed book, closed notes, formula sheet
provided)

Note:

The timetable for Registrar Scheduled exams can be found at the
University’s Enrolment Services website, http://www.ucalgary.
ca/registrar/.

6. Use of Calculators in Examinations



Only non
-
programmable calculators may be used during examinations.

7. Final Grade Determination

The final grade in this course will be based on the following components:


Component

Weight

Lab
s

5

%

Quiz
zes

20

%

Midterm Examination

25

%

Final Examination

50

%

TOTAL

100

%


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ENEL585
Course Outline


Note
s
:


1.

It is not necessary to earn a passing grade on the final exam in order to pass the
course as a whole.

2.

The laboratories will require one pre
-
lab exercise per lab group, that
is marked at
the beginning of the lab. Observations and Analysis will be marked near the end
of the laboratory period.

3.

Of the six in
-
class quizzes, the best four will be counted for grading purposes.
There will also be six take
-
home quizzes which will not
be graded. Solutions to all
quizzes will be posted at
http://www2.enel.ucalgary.ca/People/Nowicki/



8
. Textbook

Handouts of class material (in the form of chapters as related to each week of class)
will be made available from Ed’s ENEL585 website:


h
ttp://www2.enel.ucalgary.ca/People/Nowicki/

(scroll to the bottom of the ENEL585 page)


These handouts will provide you with the necessary theory for this course with
additional worked problems available from the website where quiz and exam material
from p
revious years is posted
.


The following
are reference
textbook
s only. They are

NOT
required for this course:

Title

Principles of Power Electronics

Author(s)

Kassakian, Schlecht, Verghese

Edition, Year

1st Edition, 1991

Publisher

Addison Wesley


Title

P
ower Electronics: Converters, Applications and Design

Author(s)

N Mohan, T Undeland, W Robbins

Edition, Year

2nd Edition or higher

Publisher

John Wiley

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ENEL585
Course Outline

9. Course Policies

All Schulich School of Engineering students and instructors have a responsibility

to
familiarize themselves with the policies described in the Sch
u
lich School of Engineering
Advising Syllabus available at:

http://schulich.ucalgary.ca/undergraduate/advising

10. Additional Course Information


The laboratories are scheduled as follows
, al
l in room ENA06
:


Lab 1
B01 Friday Oct. 15,
10:00
-
11:50AM

Lab 1 B02 Friday Oct. 22, 10:00
-
11:50AM

Lab 2 B01 Friday Oct. 29, 10:00
-
11:50AM

Lab 2 B02 Friday Nov. 5, 10:00
-
11:50AM

Lab 3 B01 Friday Nov. 19, 10:00
-
11:50AM

Lab 3 B02 Friday Nov. 26, 10
:00
-
11:50AM






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