VI
Preface
"r
!l
0wer
electronics, electrical machines
and
control engineering, as
taught
in
1111d,
I1Ilcler-g
r
aduate
electrical engineering courses; for additional facts, re-
(11IllSC
is
made
to
specialliterature.
However,
the
text
should
be
sufficiently
::,,11'
coutained
to
be
useful also for non-experts wishing
to
extend
or refresh
Ilwir kuowledge
of
controlled electrical drives.
Tbcy
consist of several
parts,
the
electrical machine,
the
power converter,
!.II('
('oIltrol
equipment
and
the
mechanicalload,
all of which are
dealt
with
in
v:uyiJlg depths. A brief resume of mechanics
and
of
thermal
effects in electri-
()II
IIlachines is presented in Chaps,
1-4
which would
be
skipped by
the
more
1
'::
I'I
~
ri(~llCed
reáâer. Chaps.
5-9
deal
with
DC drives which have for ove r a
"'III,lIry been
the
standard
solution when
adjustable
speed was required.
This
p;\.rl.
or
the
text
also contains
an
introduction
to
line-commutated converters
,I::
IISI:<I
for
the
supply
ofDC
machines.
AC
drives
are
introduced
in Chapo
lO,
I
>l'1';iII
Jlillg
with
a general
dynamic
model of
the
symmetrical
AC motor, valid
iII
IIpC"
the
steady-state
and
transient
condition.
This
is followed in Chapo
11
II\'
ali
overview
of
static
converters
to
be
employed for
AC
drives.
The
con-
1.1'01
;1.spects
are
discussed in Chaps. 12-14
with
emphasis
on
high dynarnic
l'I'rI'Ol'lllanCe drives, where microprocessors prove invaluable in disentangling
LIli'
1I1111Civariate
interactions present in AC machines.
Chapter
15
finally de-
::nil)('s some of
the
problems connected
with
the
industrial
application of
.IriVl's, 'l'ltis
cannot
by
any
means
cover
the
wide field of special
situations
Wil.lt wllich
the
designer is confronted in
practice
but
some frequently en-
'''IIIII.I'II'd
katures
of
drive
system
applications
are
explained there.
It
will
111''''"111'
~"Ifliciently
clear
that
the
design of a controlled drive, in
particular
"I.
Iilrl','"
pow(~r
ratings,
cannot
stop
at
the
motor
shaft
but
often entails
an
;(11:0.11':"
:: ,.I'
L"(~
whole electro-mechanical system.
III
v inv
01'
Lhe
fact
that
this
book
is
an
adaptation
and
extension of
an
"111
dical.i, 'll-oricIltated
text
in
another
language,
there
are
inevitably problems
1.'
1111
1"
'I ';:
\.rd
1.0
symbols,
the
drawing
of
circuit
diagrams
etc. After
thorough
","'::lIll.a.t.iolls with
competent
advisors
and
the
publisher, a compromise so-
I"Li!)1I
was
adopted,
using symbols recommended by
IEE
wherever possible,
1.111.
rdailliug
the
authors
usage where confusion could otherwise arise with
I,i::
r(';ukrs
at
home. A list of
the
symbols is compiled following
the
table
of
,'IIIII,I'III.S,
The
underlying principIe employed is
that
time
varying
quantities
;),1'"
IISll1\.lly
dcnoted
by
lower case
latin
letters, while
capitalletters
are
ap-
pli,'"
1.11
parameters,
average quantities, phasors etc; greek
letters
are
used
pt'l'dolllÍllalltly for angles,
angular
frequencies etc. A certain
amount
of over-
1:'1
1
iH
Illl<lvoidable, since
the
number
of available symbols
is
limited. AIso
the
l.tI
dillgl'aplty still exhibits a
strong
continental bias, eventhough
an
attcmpt
III~
:
;
IH
:t!
lt
Illadc to halance
it
with
titlcs in english
la\lf(llagl
~
.
The
list
is
cer-
I.niJlJy
III'
uo
lIWilllS
('.()Inpl<!te
hut
it
contaiJlH
t.b(~
illfp\'lllnl.ioll r\,adiJy availahle
to
t.!,,
\ anl.ho!',
Dired
rdl
:
reIl('.(:~i
i1l
1.111
:
t.I'''1.
hllVI'
11"1'11
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ill
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1,11
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wil."
1.111'
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ry
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'"
Preface
VII
The
author
wishes
to
express his sincere
gratitude
to
two
British
col-
leagues, R. M. Davis, formerly
of
Nottingham
University
and
S. R. Bowes
of
the
University of Bristol who have given help
and
encouragement
to
start
the
work
of
updating
and
translating
the
original
German
text
and
who
have
spent
considerable
time
and
effort in reviewing
and
improving
the
ini-
tial
rough
translation;
without
their
assistance
the
work could
not
have been
completed. Anyone who has
undertaken
the
task
of
smoothing
the
transla-
tion
of a foreign
text
can
appreciate
how tedious
and
time-consuming this
can be.
Thanks
are also
due
to
the
editors
of
this Springer Series, Prof.
J.
G.
Kassakian
and
Prof.
D.
H.
Naunin,
and
the
publisher for
their
cooperation
and
continued encouragement.
Braunschweig,
October
1984 Werner Leonhard
Preface
to
the
2
nd
edition
During
the
past
10 years
the
book on Control of Electrical Drives has found
its
way
onto
many
desks in
industry
and
universities all over
the
world, as
the
author
has
noticed on
numerous
occasions. After a
reprinting
in 1990
and
1992, where errors
had
been corrected
and
a few technical
updates
made,
the
book
is now
appearing
in
a second revised edition,
again
with
the
aim
of
offer-
ing
to
the
readers
perhaps
not
the
latest
little
details
but
an
updated
general
view
at
the
field
of
controlled electrical drives, which
are
maintaining
and
extending
their
position as
the
most
ftexible source
of
controlled mechanical
energy.
The
bibliography
has
been considerably
extended
but
in view
of
the
con-
tinuous
strearn
of
high quality publications,
particularly
in
the
field
of
con-
trolled AC drives,
the
list is still far from complete.
As
those familiar
with
word processing will recognise,
the
text
and
figures
are
now
produced
as a
data
set
on
the
computer.
This
would
not
have been possible
without
the
ex-
pert
help
by
Dipl.-Ing. Hendrik Klaassen, Dipl.-Math.
Petra
Heinrich, as well
as Dr.-Ing. Rüdiger Reichow, Dipl.-Ing. Marcus Heller, Mrs.
Jutta
Stich
and
Mr. Stefan Brix,
to
whom
the
author
wishes
to
express his sincere
gratitude.
Peter
Wilson has been reading some
of
the
chapters, offering valuable sugges-
tions,
The
final layout
remained
the
task
of
the
publishers, whose patience
and
helpful
cooperation
is gratefully appreciated.
Braunschweig, May 1996
Werner Leonhard
Prefacc
to
the
3
rd
Edition
'1'1111.
(,;\.\'Iy
c\"l'ldio"
of LIli: pllblislllll's
:.;Locks
oll('I'<
,d
Hll
opportullit
,y of again
II
1''':!.I,i
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IIliJlOI'
1'01'l'I'cl.i'III:
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