electric motor drives r krishnan pdf
..Power Electronics and Motor Drives..Power Electronics and Motor DrivesAdvances and pdf
Ngày tải lên :
19/06/2014, 13:20
... current
I
Q
rms reactive current
I
r
Machine rotor rms current (referred to stator)
I
s
rms stator current
i
dr
s
d
s
axis rotor current
i
ds
s
d
s
axis stator current
i
dr
d
e
axis rotor current (referred ... (referred to stator)
i
qr
q
e
axis rotor current (referred to stator)
i
qs
q
e
axis stator current
J Rotor moment of inertia (kg-m
2
)
X
r
Rotor reactance (referred to stator) (ohm)
X
s
Synchronous ... tube
electronics using phanotrons and thyratrons were introduced. Gas tube electronics proved
unreliable during World War II and, therefore, saturable reactor magnetic amplifiers
were introduced and proved...
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Electric Machines and Drives part 8 pdf
Ngày tải lên :
21/06/2014, 01:20
... IM
rotor position. (d) Generator torque (e) Motor desired torque.
138
Electric Machines and Drives
The flux linkage current relations are:
Ψ
q
r
= L
r
i
q
r
+ L
mp
i
q
sp
− L
mc
i
q
sc
Ψ
d
r
= ... L
mc
di
d
sc
dt
−ω
r
L
mc
i
q
sc
0
q
r
= R
r
i
d
r
+(L
r
i
d
r
+ L
mp
i
d
sp
− L
mc
i
d
sc
)s +(L
r
i
q
r
+ L
mp
i
q
sp
− L
mc
i
q
sc
)ω
r
0
q
r
= R
r
i
d
r
+
dΨ
d
r
dt
+ ω
r
Ψ
q
r
(67)
The electrical torque creation ... PBC+PI-(a) Regulated Motor speed and its reference. (b)Generator speed. (c) DFIG &
IM rotor position. (d)Generator torque (e) Motor desired torque.
136
Electric Machines and Drives
241.35...
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Tài liệu Cần hiểu đúng về chức năng R&D pdf
Ngày tải lên :
13/12/2013, 20:16
... bộ phận R& amp;D không thể không chú
trọng đến một quy trình thật khoa học, thật hợp lý cho hoạt động nghiên cứu
và phát triển, thường được đặt cho một tên gọi r t r r ng là “quy trình
nghiên ... phát triển”. Quy trình này quy định trình tự các bước thực hiện
trong hoạt động nghiên cứu - phát triển, mô tả sự phối hợp giữa bộ phận
R& amp;D với các bộ phận khác trong doanh nghiệp như marketing, ... hoặc phát
triển công nghệ mới cho mình.
Nghiên cứu - phát triển quá trình (Process R& amp;D)
Bản chất của chức năng này là nghiên cứu, tìm kiếm các quá trình sản xuất,
chế biến, lắp r p, vận...
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Pseudo vector control – an alternative approach for brushless DC motor drives
Ngày tải lên :
03/01/2014, 19:46
... the currents are controlled by 3
current controllers in stationary frame. By convention, the
superscript
*
refers to the reference variables and quantities.
The reference currents generating ... Control for BLDCM drives.
INVERTER
BLDC
motor
Load
PWM
Current
Controller
Current
Controller
Current
Controller
*
a
i
*
b
i
*
c
i
+
+
+
−
−
−
a
i
c
i
()
bac
iii=− +
Measured currents
d-q
to
a-b-c
a-b-c
to
d-q
a
e
b
e
c
e
Reference ...
paper is described in Fig. 3 where the part generating current
references is marked by the break-line frame. For the purpose
of comparison, a typical Vector Control scheme for
synchronous motors...
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Tài liệu Electric Motor - động cơ điện ppt
Ngày tải lên :
26/01/2014, 08:20
... s
Figure 4.5 Speed-torque curve of
2-phase motor showing harmonic
torque.
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill ... inner bars, or all over the cross section of a deep bar, owing
to their lower resistance.
4.1.5 Analysis of induction motors
Induction motors are analyzed by three methods: (1) circle diagram; ... (2)
equivalent circuit; (3) coupled-circuit, generalized machine. The first
Figure 4.6 Alternating forms of squirrel-cage rotor bars.
Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright...
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- 3
Chapter 13 induction motor drives
Ngày tải lên :
16/02/2014, 18:54
... rotor current vectors, as expressed
in the synchronous reference frame, are perpendicular. Furthermore, if they are perpen-
dicular in the synchronous reference frame, they are perpendicular in ...
λ
ω
r s M
r
s rr r
I L
r
L r
=
′
′
+
′
2 2 2
(13.3-7)
ROBUST DIRECT FIELD-ORIENTED CONTROL 527
Figure 13.6-3. Robust direct rotor field oriented control.
Figure 13.6-4. Start-up performance of robust ... slew rate, this would have required a larger starting current and therefore a
larger and more costly inverter. There are several other compensations techniques set
forth in the literature [1,...
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Chapter 14 permanent magnet AC motor drives
Ngày tải lên :
16/02/2014, 18:54
... ms
150
-150
150
-150
150
-150
5
-5
5
-5
5
-5
2
-2
v
as
,V
i
as
,A
v
qs
,V
r
v
ds
,V
r
i
qs
,A
i
ds
,A
r
r
T
e
, Nm
CURRENT-REGULATED INVERTER DRIVES 567
14.8. CURRENT-REGULATED INVERTER DRIVES
Sections 14.1–14.7 explored the performance of drives in which ... stator currents. The hardware confi guration for current-regulated inverter
drives is identical to that of voltage-source inverter drives, as illustrated in Figure 14.2-
1 . The only difference ... CASE STUDY: CURRENT-REGULATED INVERTER-BASED
SPEED CONTROLLER
The control of current-regulated inverter drives is considerably simpler than for their
voltage-source-based counterparts, due to...
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power electronics and motor drives - advances and trends
Ngày tải lên :
05/03/2014, 09:32
... stator current
i
dr
d
e
axis rotor current (referred to stator)
i
qr
q
e
axis rotor current (referred to stator)
i
qs
q
e
axis stator current
J Rotor moment of inertia (kg-m
2
)
X
r
Rotor reactance ... load current
I
m
rms magnetizing current
I
P
rms active current
I
Q
rms reactive current
I
r
Machine rotor rms current (referred to stator)
I
s
rms stator current
i
dr
s
d
s
axis rotor current
i
ds
s
d
s ... 1930 – New York subway installs grid-controlled mercury-arc rectifie
r
(3 MW) for dc drive
• 1931 – German railways introduce mercury-arc cycloconverters for
universal motor traction drive
• 1933...
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Institutional Investment in Hedge Funds: Evolving Investor Portfolio Construction Drives Product Convergence pdf
Ngày tải lên :
07/03/2014, 13:20
... Evolving Investor Portfolio Construction Drives Product Convergence
that focus on resource-based offerings rather than corporate
restructurings, although more hedge fund managers are also
beginning ... strategies that are either fully in the
private markets or that bridge the private and public markets
and base their return stream around real assets, or what some
investors refer to as hard assets. ... offer
investors ownership stakes in emerging markets or frontier
region projects such as toll roads or power plants.
Risk-Aligned Portfolios Reposition Hedge Funds
From Satellite to Core Holdings...
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Practical Electric motor handbook pptx
Ngày tải lên :
09/03/2014, 17:20
...
The electrlc motor as an energy converter
At the very outset, we should concern ourselves with what electric motors
do. A popular but erroneous notion is that electric motors create or produce ... when working with electric motors. Included in their
company are electrical engineers for the simple reason that their training
probably focused more on software, programming and computer logic ... energy accumulates in order to
obtain power. We are charged for our use of electrical
energy.
For example,
one hundred kilowatt-hours (kWh) of electrical energy could result from
100-hours...
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BUSINESS CYCLE ACCOUNTING BY V. V. CHARI, PATRICK J. KEHOE, AND ELLEN R. MCGRATTAN pdf
Ngày tải lên :
15/03/2014, 22:20
... entrepreneurs. Here we solve for optimal debt-like contracts that
arbitrarily rule out such risk sharing, but even so, our first-order conditions
differ from those of Bernanke, Gertler, and Gilchrist. ... on borrowing by firms in sector i.Iffirmsin
sector 1 are more financially constrained than those in sector 2, then R
1t
> ;R
2t
.
Let R
it
= R
t
(1+τ
it
),whereR
t
is the rate consumers earn within ... Gilchrist. (One reason for this dif-
ference is that our break-even constraint for the financial intermediary and our
law of motion for entrepreneurial net worth differ from theirs. See equations
(35)and(37)below.)
824...
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Database Design by Ryan K. Stephens Ronald R. Plew pdf
Ngày tải lên :
30/03/2014, 22:20
... organizations are integrating the concept of the
N-Tier architecture. The N-Tier architecture is a concept similar to a middle tier or three tier
computer architecture. In a three tier architecture, there ... EDITOR
Charlotte Clapp
PROJECT EDITOR
Carol Bowers
COPY EDITORS
Rhonda Tinch-Mize
Bart Reed
Mary Ellen Stephenson
INDEXER
Bill Meyers
PROOFREADER
Katherin Bidwell
TECHNICAL EDITORS
James Drover
Beth ... application
for the client/server computing environment, which might require a more powerful
server with more memory, depending on the number of concurrent users. However,
the benefits of using Designer...
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- 2
Electric motor controls tutorial
Ngày tải lên :
13/05/2014, 11:23
... Curve
Motor Damage
Allowable Operation Area
Amperage
Time
Motor Current Draw
Motor Running Current
Starting In-Rush Current
Overload Protection
Overload protection is installed in the motor circuit ... Code requires that
motors and their conductors be protected
from both overcurrent and overload
conditions.
Overcurrent Protection
Overcurrent protection interrupts the electrical circuit to the motor ... de-energize the circuit to the motor along with additional motor
overload protection equipment.
C Magnetic starters are used with larger motors (required above 10 horsepower) or where
greater motor...
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báo cáo hóa học: " Measuring adolescents'''' HRQoL via self reports and parent proxy reports: an evaluation of the psychometric properties of both versions of the KINDL-R instrument" pdf
Ngày tải lên :
18/06/2014, 19:20
... D-13353 Berlin, Germany
Email: Michael Erhart - m.erhart@uke.de; Ute Ellert - ellertu@rki.de; Bärbel-Maria Kurth - kurthb@rki.de;
Ulrike Ravens-Sieberer* - ravens-sieberer@uke.de
* Corresponding ... for the self-report version, these corre-
lations were 0.36 and 0.52, respectively. For the parent-
report version, these correlations were 0.63 and 0.78
respectively. The correlations were transformed ... factor load-
ings and factor correlation across age groups for either the
self reports or the parent reports (results not shown).
Self-proxy agreement
Detailed information on the self-proxy agreement...
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ENGINEERING ACOUSTICS EE 363NINDEX (p,q,r) modes pdf
Ngày tải lên :
27/06/2014, 17:20
... total
reflection with the waveform inverted.
1,0RT
≈−≈
21
21
r
i
Prr
R
Prr
−
==
+
2
21
21
I
rr
R
rr
−
=
+
2
21
2
t
i
P r
T
Prr
==
+
( )
21
2
21
4
I
rr
T
rr
=
+
P
i
, P
r
, P
t
... power level:
rev
SPL610log
w
LR
=+− [dB]
Energy density (reverberant):
rev
rev
44
WW
AcRc
==
E
[J/m
3
]
SPL
rev
= sound power level in the reverberant field [m]
r = distance from the source ... definition
{
2
area of a
spherical
surface
4
rI
Π=π for spherical dispersion
{
2
hemi-
spherical
surface
2
rI
Π=π for hemispherical dispersion
S = surface surrounding the sound source, or at least...
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