Lecture 2 basics of electric machines

Lectures on Electrical
and Instrument
Engineering
Lecture-2
Basics of Electric Machines

Stator Windings Partially Completed

Rotor Lamination
~ti!~
~.%......._ .. __.,.
·- -- -% ~
~!It~

EodRi09
cutawa'f View ot Rotor

Partially Assembled Motor
Air Gap
Stator

Cutaway View of Motor
End Bracket
(Bearing Housing)
Frame (Yoke)
Bearing
End Bracket
(Bearing Housing)

Magnetic Lines of Flux
Magnet
Iron Filings on Paper

Lecture 2 basics of electric machines

Electron Flow TowardsYou
Causes Clockwise Magnetic Flux
(8)Electron Flow Away From You
Causes CounterclockwiseMagnetic Flux
(G)

Air Core
j;..
. .
Yy
<l.
• :J
.. •:. .:. . . . ~ ... '•
....
. .. .
DC Voltage

10 Tums5Tums
...~~.: --:::.. /:·:·.:~~---.
. : .
DC Voltage .f~ ~ Y Yy
4. ·. ·._·_._. ·:_.:::.J:./. . . . ....

Time 3
·• ':..1 -;i' .:
-~- :.:7·
···>···
s
Ammeter
Time 2
''..l .••• ' ·>.... -:i·
.... ·1>- ...
;7' ·"'Ghlrl"*>r..µ- :.I
... -:f •:.l
N
o~

Ammeter
Time 1
Ammeter

To Phase A
To Phase A
Phase A Phase B Phase C

A
I I I
1+--60°~ I
I I I
I I I
B
I I I
1' ~ '1
1E
I
360°~:
Start 2 3 4 5 6
c
Al Al Al A1
::9:: :8): ::9: ::9::A2 B2~AIC2 ~ 828!;'.1cz i'Ble") S" A2
C1 Bl C1 S .. ·:: 81 I C1 //:: 81
I
A2 A2 I A2
I____ ,

2 3600
4 1800
6 1200
8 900
10 720
No. of Poles Synchronous Speed
Synchronous speed decreases as the number of poles
increases. The following table shows the synchronous speed at
60 Hz for several different pole numbers.
Ns = 120F c::;> Ns = 120 x 60 c::;> Ns = 3600 RPM
p 2

% Slip= 1.4%
% Slip= 1800- 1775 x 100
1800
For example, a four-pole motor operated at 60 Hz has a
synchronous speed (Ns) of 1800 RPM. If its rotor speed (NR)
at full load is 1775 RPM, then its full load slip is 1.4°/o.

/
SIEMENS '
0 0
NEMA PREMIUM EFFICIENT
ORD.NO. 1 LE2321-2CB21-2AA3 ~o.l
TYPE 80100 FRAME 286T
H.P. 30.00 ~f~¥1§',1' 1.15 I 3 PH
AMPS 35.0 VOLTS 460
R.P.M. 1775 HERTZ 60
"'DUTY CONT 400CAMB. I cc;~ I
.,
CLASS
F I "'"" I B I K.V.A. G I~'.~;. I 93.6
~
INSl.ll oi::SIGN OOOE ....
SH. END
50BC03JPP3 OPP (NO I 50VC03JPP3
r;-
BAG.
~..... LO
0 Made in Mexico by SIEMENS @ c'il~s ( E @ 0

1S0°= 1S0°= 1so0- 1so0-
=}15°
1S0°- 160°- 160°=
==}10°
160°=
140•= 140•= 140•= 140•=
120°= 120°= ~}10° 120•= 120•=
100°- =}s• 100°- 100°- 105° 100°- 125°
so·= so· so·= so- so·= so·=
so·= so·= so·- 60°-
40°= 40°= 40•= 40•=
20°- 20°- 20·= 20·=
o•= o·= o•= o•=
Class A Class B Class F Class H
60° CRise so- c Rise 105° C Rise 125° CRise
5° CHot Spot 10° C Hot Spot 1o- c Hot Spot 15° CHot Spot

% Synchronous Speed
0
0 10 20 30 40 50 60 70 80 90 100
/
......-
-,
/ '

225
., 200
::>
e- 175~
-0
"' 1500_,
..L
:; 125u,
'if.
100
75
50
25

% Synchronous Speed
0
0 10 20 30 40 50 60 70 80 90 100
Constant Torque Load 2 / r: r'.
v 'I

, Constant Torque Load 1
/ <>'),. vZI
/
/ fk <foo'/ '.rYo.-S ~010."9IC
).0 . !()9 v.,.,.,_ ?i-.;p, la1'a
~ZI J .+ .~
250
225
"'
200
;:>
ET
175{<
"P
"' 1500_,
':; 125u.
~0
100
75
50
25

2;g = 3.8 V/Hz ~g = 3.8 V/Hz
30 60060
460 230
6Q = 7.67 V/Hz
30
= 7.67V/Hz
30
Frequency
0
ss 230
g
460

60

5040

30
Frequency- Hz
o~~~~~~~~~~~~~~~
0 10 20 30 40 50 60 70 80 90 100
% Synchronous Speed

202 10
225
200 ·.,•.
175 '
"'=>
150
.';.
B" .-... . ' .,i!2
125"O
"'0
,CJ
100..!.
:;
LL
75
~0
50
25

L1 L2 L3
I I s I
T
1 3
Tm;:u
01
r
Resistivetorque
1 3 5 • N
a a N1Nn
KM1 ·-·-· .....
2 4 6
..,.,
1 3 5
F2
lf(Tr)
2 4 6
,,
u v. w N
N1 Nn
M
3-

Star-deltastarting
2 4 6
KM1
2
S
4
1 3 5
KM3 S
2 4
1 3 5
u

TST2 T7
Part winding starting
T1
L1 L2 L3
J J J
KM 1 _ _ _ _ _ _ ___

Breaking
Principleofcountercurrsntbtaldng
M
wv
M
w
L3L2
u
l1L3
Operation
L2
vu
l1

PtJnclpleofcountercvrr61UbtaJdngIn art
asynch/Onousslip rlng machine
Breaking
0
wvu
L3L2L1
Opefation
''•'''
wv
wv
L3L2
u
u
L1

I lft&M Principleof direct currMt btal<JngIn an
asyrtehmnous machine
M
30
wvu
L3 ILI

Prlnclp/o ofasynchrt:>tlOUsmolot
"'"""'Ing
M
3121
wv
L3L2
u
L1
1•;111.1

....
' ' "
Current step 1
with resistance
Nn
N
Current step 2
-- ............ .... ....
--
Direct current
0
1
4
Id/In
6

Resistance stator starting
Nn
N
Tr
Torque step 2
Torque step 1
__......
-- '// '/
Direct torque/ /
/
0.5
1
1.5
T
Torque

Nn
N
' '
Autotransformer starting
1
----
,.,,,,,
Direct torque , »" Step 2
,. ------,.1.5
~
------Step 1
T
10050
N0
......
......
--------------------~
--
......
' Current step 2
' ''
Torque
step 1
---- -
---- - .._
I direct
4
Id/In
6

Slip ring motor starting
KM1
F.2
L1 L2 l3
R3 AIB/C
1 3 5
:~ - ., 3
J ~2 4 6
KM13 I
R2 AIB/C 2 4 6
1 3 5 -
J
2 4 6
- .~J 3 J ~I 3 5
KM12 II I I
R1NB/C 2 4 6
2 4 6
-
u I<
-v
{(3~
L
J ~
- - - 1 3
- - Km11 I
w M
2 4 6
-
QI

Multiple motor starting with a soft
M2
3 ""'
- " "'
0
- " "'
N ~ ..
t 17i . ;
Mall!tlr 1
M1
3 "'
5 ; i
• K.M2t '>---,,..-'- KM22 '>--""'<--'
N ~ ..
-03
(1)
-0
I><ALrr
~
-1 Ml "'l
~A' ~All
KAT If KAl.lT.,
1

N • e
~~ z
"' e, I
';' ~ - g
!
:; ~ .. I0 Q
- M
"' (2)
-Tl ..
' ~ 2 I 2
N
• .. ,
( ) -1 2
~
'" I
''
'--- " -··......-...
--
~~ ~
M I
M ~
I ~ ~ g
..........
' ·:::~
- M
"' - " "' -J "J "' - " "' - M
"'' ' ' '

Working diagram of a frequency
converter
u
v
w
Filter
t .Fig. 8
()I
Rectifier

Single-phasemotor with auxiliary
phase
L1 L2
u vK
Main winding
L
Quadratic
winding
t Fi~. 10
optional
centrifugal
clutch

Single-phase motor with starting
capacitor
L1 L2
v
Main winding
f rsr:': • •
.rig. '1 J
L u
Starting
capacitor
K
optional
centrifugal
clutch
Quadratic
winding

Rings
magnetic field
Winding
magnetic field
Stator
Shaded pole winding motort F. i»1.f[. .J -
L2L1
vu

Principle of countercurrent braking
Breaking
M
wv
I I
llI
L3L2
I II I
lI
u
L1
Operation
w
L3
M
v
L2
u
L1

Breaking
v
Principle of countercurrent braking in an
asynchronous slip ring machine
w
v
uw
w
L3L2L1
uw
L3
Operation
v
v
L2L1
'''''d
u
u

Principle of directcurrent brakingin an
asynchronous machine
M
30
v w
L3L2
u
L1

M
30
Principleof asynchronous motor
reversing
wv
L3L2
u
L1

2-wire
control
-51
:;
-QF1
-v230V
3-wire
control
-QF1
<
-$2
-S1
"'230V

Equivalent diagram of an asynchronous
motor
•••QI
Magnetic Iron Active
flux losses, power
inductance I
I
lof
I
I
I
I
Energy
losses
Leakage
inductance
Stator Rotor
......

Losses in a AC motor
Rotor
Stator
iron
losses

rso-c125°KCategoryH
iss-c1os°KCategoryF
izs-cao°KCategory B

Windings are the motor parts most
vulnerable to electrical faults and
operating incidents
t Fi'g.37
Stator
win

Lifetime of motor depending on
operating
t Pig. 39
1, 15xln Current
T+30° Temperature
0%+-~~~~~~~~~~~~~~---i
In
T
1, txtn
T+20°
1,05xln
T+10°
~75%··t-~-"<::--~~~~~~~~~~~--;
E
~50%t-~~~--'""'"~~~~~~~~~---J
_J

Example of a voltage surget Fig. 40
T
v

3 phase unbalanced voltagest Fig. 42
v

Motor derating according to unbalanced
voltage in its power supply
5%4%2% 3%1 %
0,7 +---~---~--~---~----+--
0 %
' Voltage
; unbalance
1 r·.::..:.:·. ·:..:.:.·..:.:.:·.·.:.:.·.·::..:·........ .......... . ............... . ·.
''
'
'
''
Derating
factor
0,8
0,9

Example of a voltage drop and a short voltage
break
1.Fig. 45
------..__ ----
~ _,_,_
-,
t
- --~-·--- - ------ -·-
v

Starting time based on the ratio of starting
current to rated current
15 s107543
1
1
t
5
0
9
<,
Q
....r-,
7
......
-,
6
<,
5 I'-.....
..... ....
4
r.... ~
....
',
'3
Id/In
20

Summary of possible faults in a motor with their causes and effects
•u•ac•
Faults Causes Effects
Effects on
the motor
Short circuit • Phase-to-phase, • Current surge • Windings destroyed
phase-to-ground . • Electrodynamic
winding to winding stress on conductors
Voltage surge ·Lightning - Dielectric breakdown • Windings destroyed by
• Electrostatic in windings loss of insulation
discharge
• Disconnection of a load
Unbalanced voltage • Phase opening • Decrease of the ·Overheating(•)
• Single·phase load available torque
unstream of motor ·Increased losses
Voltage drop • Instability in mains • Decrease of • Overheating(•)
and dip voltage the available torque
• Connection of ·Increased losses
high loads
Harmonics • Mains supply pollution • Decrease ot • Overheating(•)
by non linear loads the available torque
• lncreased losses
Starting too long • Too high a resistant • Increase in • Overheating(•)
torque starting time
• vcrtaoe drop
Lockina • Mechanical oroblem • Overcurrent • Overheatina(•l
Overload • Increase in resistant • Higher current ·Overheating (•)
torque consumption
• vouace drap
("') And in the short or long run, depending on the seriousness and/or frequency of the fault,
the windings short-circuit and are destroyed.

Overload relay tripping curves
7.2 Ir
I/Ir
1.051r 1.51r
1.2 Ir
Class 30
11@}1
10
20
30
t (s)

Thermalmagnetic circuit breaker operating
zones
lcs lcuIm linstIr!
1.ocl 1ri 1.2 Ir
t(s)
t Flg. 6.

Wound
Rotor
Squirrel
Cage
ShuntSeries Compound
Stepper Reluctance Induction
AsynchronousSynchronousBrushed Brushless
DC motors AC motors
Motors

R.otating
Fan
Shell
'=--""'Commutator
=MDtor Brush

Terminals
Stator tease)
'"mdmg1'
Rotor
TypicaJ Brushed Motor in Cross-section

LOADvT ,_
--
a) Separately Excited DCmotor:

ARMATURE
INPUT
VOLTAGE
SERIES
FIELD'
DC Series Illotor

ARMATURE
SHUNT
FIELD
INPUT
VOLTAGE
DC Shunt 01otor

A Rl'Vll£T URE
SHUNT
FIE• o
LONG
SERIES
FIELDJNPIJ"T
VOLTAO#
Colllpound Motor

CUMULATIVE
t
-
'SUPPLY
VOLTAGE
J

DIFFERENTIAL
-
SUPPLY
VOLTAGE
l
+

T...ICompound Connect.ed DC Mot.or
ShunL
Field
Series
It Field
r.
+
1--11...~
v- Constant
T
1.-- ... -
It - Constant
...
Series Connect.ed DC Motor
T
+
!t
V =Constant.
T
It ...
!t co
V- Constant
T ...
Tt
Shunt Connected DC Motor
+
vf
+

Tlmiri Ring
Brus he
0
0
Stack
IArmature

de motors
Feed uack sye""t:em
arid gearl:;Jox
Pot
Control ci rcultry
RC servos

position
sensor
/command
error/
servo motor loadstepper motor lo ad
command

LG ...____.¢>-+--t-r....-.0-----~--t-_._YJ--1~~
l..2.--t,J;ap--..~.!,h~~~~----Jl.-.---6.~
1L1 _,
U3
W3
I
2

r-1 .
.. -·.
.: -,.
:n1
.:1 - n
""f" ~
n_t
,-
~~
I I v
..; .
#6. ,. '.
·~ -, ...
.. - .f - ..,.... - - '
,,
'
...,
~ .. - -
L3 ---i
L2 ---!
l1 --ii

LU-:
CONTACTOA
.
-~~--c:o-~~-1o~
: l._oiikJ-~
••.
-~~~~:--~~__. ......
: L--.k:l--~
lrivru510A
STACK

Motor
+
Inverter
Circuit
Fixed
DC
Voltage
Rectifier
Circuit
Input
Power

LI~ o---------__i
ex I l::H NAL
RESISTORS
Lll'E

• Input Power
• Single Phase
- Watts= Volts X Amps X p.f.
• Three Phase
- Watts= Avg Volts X Avg Amps X p.f. X 1.74
Watt's Law

• Is a 1 Hp l-phase motor driving a fan overloaded?
- Voltage = 123 volts
- Current = 9 amps
- p.f. = 78%
• Watts= Volts X Amps X p.f.
Watts= 123 volts X 9 amps X 0.78 = 863.5 Watts
864 Watts I 746 Watts/Hp= 1.16 Hp
• Is the motor overloaded?
Example

• We measured Input
• Motors are rated as Output
• Difference?
- Efficiency
• If the motor is 75%
efficient, is it overloaded?
• Eff = Output I Input
• Output = Eff X Input
0.75 X 1.16 Hp= 0.87 Hp
• The motor is NOT
overloaded
Electrical = Input

• Is this 10 Hp, 3-phase motor overloaded?
- Voltages= 455, 458, and 461 volts
- Currents= 14.1, 14.0 and 13.9 amps
- P.f. = 82%
• Watts= Voltsavg X Ampsavg X p.f. X 1.74
Watts= 458v X 14a X 0.82 X 1.74 = 9148.6 Watts
9148.6 Watts I 746 Watts/Hp= 12.26Hp
• Is the motor overloaded?
Example #2

Hp
Output?
• We measured Input
• Motor is rated as Output
• Difference?
- Efficiency
• If the motor is 90%
efficient, is it overloaded?
• Eff = Output I Input
• Output = Eff X Input
0.90 X 12.26 Hp= 11.0 Hp
• The motor IS overloaded!
• How bad is the overload?
Example #2

SPEED (% OF SYNCHRONOUS SPEED)
1000
rDESIGN LETIER
'/
D
--- r---... -.... /I ~
.
<, I
<, / /(" ......
~ , / .....:'.'. ......~
- ,,,.
fr--..... A ,,..- /
~
I I
I

-
NEMA CLASSIFICATION
300
• 3 Phase Induction ~
w
Motors
:::>
0
a:
0
200
• NEMA Torque- I-
0
<(
Speed Design 0
...J
•...J
Types
...J
ir
LL 100
- A,B,C,D,E 0
cw
:::>
0
a:
0
r-
NEMA 3 Phase Motors

• Today's "Standard" 3-
Phase Motor
• Good Starting Torque
- In-rush amps 4-6 times
full load amps
- Good breakdown-
torque
- Medium Slip
Design Type B

• Higher in-rush current
(5-8 times full load
amps)
• Good breakdown
torque
• The "old" Standard
• Higher starting torque
than "B".
Design Type A

• CommonOEM
equipment on
reciprocating pumps,
compressors and other
"hard starting" loads.
• High starting torque
• Moderate starting
current (5-8 times
FLA)
• Moderate breakdown
torque
Design Type C

Design Type D
• Common on O/o
applications with RATED
significant loading TORQUE
D
changes as a machine 300
operates.
200
• Impact Loads
- Punch Presses, Metal 100
Shears, etc.
- Pump Jacks 0
0 20 40 60 80 10
0/oRATED SPEED

0 20 40 60 80 100
% RATED SPEED
0
100
"lo
RATED 200
TORQUE
JOO
I I Switching
- Stan Ing PJ'nl -
and Running --Windin~-j ... / I=-..
Runn'"2.,f
Windio
LINE
•••••• •• •• • •• •• •••••• CENTRIFUGAL
SWITCH
STARTING WINDING
RUNNING WINDING
• Starting winding in
parallel with Running
winding
• Switch operates at
70-80% of full speed.
• Centrifugal Switch
- Sticks Open
- Sticks Shut
Split Phase Motor

%RATED
TORQUE 100
200
LINE
......
/
v
_,... ...,,..,

---~
CAPACITOR WINDING
•••••• •• •• • •• •• ••••••
10020 40 60 80
O/o RATED SPEED
0
0
CAPACITOR
IWINDING
·.----·-· ···-·-·-·
• Capacitor in
"Capacitor Winding"
- Provides a "phase
shift" for starting.
- Optimizes running
characteristics.
• No centrifugal switch
PermanentSplit Capacitor(PSC)

10020 40 60 60
% RATED SPEED
0
0
100
%
RATED
TOROUE200
300
400
' I ,..,.,. Switching
Maln and
auxlUary/ ' ~Olnt -
wiidings
I
'Main ,/I .
Winding
,
RUNNING WINDING STARTING WINDING
c·ENTRIFUGA
SWITCH
I
LINE
• • •• •• ••••••
STARTING
CAPACITO~
• Very high starting
torque.
current.
• Common on
compressors and other
hard starting
equipment.
CapacitorStartMotor

10020 40 60 80
'l'o_RATED_SPEED
STARTING WINDING
0
0
100
% 200
RATED
TORQUE
300
Stanlng and I
-Running W1n~in1g
-"Switching'
Point
Running ...
Winding ,. .
RUNNIN!3 WINDING
•••••• •• •
• • •• •• ••••••
LINE
RUNNING
~CAPACITOR
STARTING
CAPACITOR"
CENTRIFUGAL
SWITCH
• Larger single phase
motors up to 10 Hp.
• Good starting torque
(less than cap start)
with lower starting
current.
• Higher cost than cap
start.
CapacitorStart-RunMotor

0
0 20 40 60 90 100
~~~~~~~~~~~~~~~~~~~·%RATEDSPEEO.~~~· ,
%
RATED ISO
TORQUE
I I / '
_............... I
.._ =·' -
SM1chir19
I,.' Point
• " lJ'/ ' ,
Running..
W1nd~g
'100
ROTOR SHAPE
• Special design for
"constant speed" at
rated horsepower and
below.
• Used where
maintaining speed is
critical when the load
changes.
Synchronous Motor

0
0 20 40 60 80 100
% RATED SPEED
100
%
RATED 200
TORQUE
JOO
400
' .
r-, ' I
-, ,.,. DC -<,
" ~ -,
60 Hz AC r-, -,
-.......... <,
~
LINE
torque.
• Higher torque on DC
than AC (battery
operated tools)
• The higher the rpm,
the lower the torque.
STATOR POLE r==~=t::
Universal Motor

Nn·~-----------
Currentstep 2
Cl~fllfl&p I
wtttt"''151J:nc•
M
3-
ldllk1 Dint~ curte1l1
6 -- --
--u
2 4 6
F2
5
6
KM11
4
35
2 4
KM1
1 3
01
L1 L2 L3
1 3 I s

M
3-
u
w
V3
U3
KM3
KM2 u~·-iii··w
F2
L1 L2 L3

Insulation resistance temperaturet Fig. 38
Temperature
so •c60 -c40 •c20 -c
0,1+-.._..._..._..._-+-_.__.__.__.._-t-_..__.__.__._-+-_.__.__._~-1
o•c

Armature
1-phase
supply
Main field
winding Compensating
winding

Fig. 2. Series motor with inductively compensated winding
Armature
Compensation
winding
I-phase
supply
Main field
winding

Fig. (3-a). Schematic diagram of conductively coupled ac series motor.
Annaturei.z,
ac supply Compensation
winding
1-
I,zse
I. z, Interpole
Series field

Fig.(3-b). Phasor diagram
uz;
i»,
uz; laRa
laXc
laZt laRe
laX1
laR1

Fig.(l)four phase 4/2 VR stepper motor

N5 =stator poles (teeth)Where
a = step angle
ni, = number of stator phases or stacks
N; = number of rotor teeth (or rotor poles)
The step angle is also expressed as
Where
360
The magnitude of step angle for any YR and PM stepper motor
is given by

Fig. (2): four- phase, 8/6 VR stepper motor.
(0)
."'-
~
I
I
(a)

Fig .5 2-phase 4/2-pole PM stepper motor
(d)
. ' s
•a
.,.
la) •,,

(b)Phaa« dJ~ram
...
Sqwret
cege rotor
(a) SchemaUe repre.MntatJon
I
v

(b) ~allent pole wtth ahldlng band
,____ Salient
pole
--Shading
bn
Squirrel
cageroa
(1)4 ·pole ah~ pole constNctlon
--
Stator
wind'"Q. __
~~--- .......- Shad.n;
bet.t

:: X1M=•
==80%
i----&ns---1
HIGH
--t Sai:a1.i--
llGH o:; Xt••ll
Time Slgnal
Duty _ In High State X
1
OO
Cycle - Period of Cycle
~o.s.-i
• Pulse Width Modulation

H-BRIDGE DC
PROCESSOR
CIRCUIT MOTOR
i
ENCODER

OUTPUT= INPUT X GAIN
GAIN PLANTINPUT .. .
Open loop control system

OUTPUT = (INPUT - OUTPUT) X GAIN
1----------+t PLANTGAIN
Closed loop control system

PROCESSOR
H-BRIDGE DC
CIRCUIT MOTOR
!
ENCODER
Motor control diagram

OUTPUT = (INPUT - OUTPUT) X (P GAIN + I GAIN + D GAIN)
SUM~ PLANT
'------FEEDBACK------'
D GAIN
I GAIN
P GAIN
SUM~
PID control system diagram

1 43
TIme
20 6
0.4 ··-·······-····-···------·-·--· -· ·---11t
- Command
0.2 • • • pGlln:: 2. IG.aln = 0.1
••• pGaln = 2. IG.aln = O.OS
- pGlln = 2, IG.aln = 0.02
o -···-·-···.:·---·------- ... • pG.in = 1, tGaln = 0.02
,
•
, i i
I 4 -- ··-----·-- ...., - r·-
1 ' •
I t i i
1 .--"""""i'!!'~-~ .-..~-~--.,--"'!lIt A • • '
• ,- I
0.8 - . , # -r-········--~----··->-·--·1 ···-··-+ ..
, i .,
•
1.2
• Set point
• Rise time
• Overshoot
• Settling time
• Peak time
• Overdamped
• Underdamped
Sample PID output chart

FIGURE 1.3. A linear DC motor.
R
fr
I
l ® ® ® ® e e ®
® ® ® ® ® -. F
vs + l magnetic
e e ® ® ® e
'e ® ® ® e
l
e @......__
A
y~-®
e ® e ® e e B=-Bi
xA x
z
(out of page)

FIGlJRE 1.2. Only the component B.l. of the magnetic field which is perpendic-
ular to the wire produces a force on the current.
(b)(a)
N
-f_
8
~..__-
~-----s ~
~--
~--
.l

~ ~
BJ.~ ~--
_e e :<J--
B ~ ~,_____-
~..__- ~>----
-....J .....____ - ---- .___
B

FIGURE 1.2. Only the component BJ. of the magnetic field which is perpendic-
ular to the wire produces a force on the current.
(b)(a)
B
-e
l

<I <I
<I
<I
s N
<I
<I
<I
or, in scalar terms, Fmaguetic = iPBsin(O) = i£BJ_. Again, BJ.. 6
Bsin(O) is
...
the component of B perpendicular to the wire.1
__, - __,
Fmagnetic = if. X B

FIGURE 1.4. Soft iron cylindrical core placed inside a hollowed out permanent
magnet to produce a radial magnetic field in the air gap.
air gap
s
B=-Br B=Br
N

FIGURE 1.27. A multiloop armature for a DC rnotor.

A VOLTAGE IS INDUCED IN THE STATIONARYCONDUCTOR
WHEN THE MAGNETIC FIELD MOVES ACROSS IT. REVERSING
THE DIRECTIONOF MOVEMENT OF THE MAGNETIC FIELD
WILL CAUSETHE DIRECTION OF THE INDUCED VOLTAGEAND
RESULTING CURRENT FLOWTO REVERSE.
FlXED--
COHDUCTOR
DIRECTIOll
OF
MOTION
s
THE PHYSICS OF GENERATOR ACTION

AC output
11
excitction
Ffeld
Stator field
THE BASIC GENERATOR

Slotor
lie1d (slotk>nory)
Brush
. ' .
' '
' ''' ..' ''' .'..'
'.'' '.'.'''.'.';',''
Exciter
Oe!d
rhcoslal
• •
.'''.'I,
'''
Field
excHolion
Jn,

Phase 1
Q)
g' +
.....
0
> 0 l-'---t---t-+---'t--1-1-'r---+-.....,_i-+-_-+-+
-:J
c,
~
::i
0 -
Phase 2

0 VOLTS
DEGREES Of
ROTATIOH
MAXIMUM
VOLTS0 VOLJS
+
MAXIMUM
/OLIS
D'

0 e CY(:One Cycle
I
N
4
~ ' 6
-5 • . ~
6/ /'z £ T / 3
5~
,, J 1:1 1
"
7~ I/ ~ . ""j "' I ll
1t
I1 2:
- t-
~I'
1
'I I/
,~ I v1: 2•
a'.../ / 8 Q I! I/ 21 I 21 11. I/
9
_,. - 1;:..
t
<; 10 _/ 10
s .
- len

-1.0 .__ _,
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
KILOWATTS PER UNIT
1 ~E~~-:.._____ ARMATU~E CORE
-0.8 111 END IRON
HEATING llMfTATION
-
:--------·c
THRESHOLD
LIMIT
ARMATURE
VlNOING
HEATING
LIMITATION
+0.4
oi------
+0.2 ,__ _
o
z +0.6
0
C)
~
FIELD 'lllNOING I
l---H_EA_,r.,.u~•A_IT_A_r1_o_N__ RATEO PF
+0.8 LAGGING ---i
/
+1.0 --------------
a:
LU
~t:
a.z
LU :::>
>a:
i= IJJ
oa.
<LU
a::

2) eo 7!!1 100 ·~ 1~0 ·~ zoo 22' aso m
'IELO AMnAES
0
0.
0
Q.2
0..
0
6t00w1.
·"'
I
I
/
VNOLOAD SATURATION
2 ()
) /
(('-~
•I
~"I
0 '
. "'1
UN¥/ o/ I/
Got.S GAP i: I
j
' ,,~/ ~1 IJI
I ti. I
I,
• !4
.1
IM"WANC / O ) p;
J ~ , IO>• ~~/jo
.!> I C)
I / :/It 0
I
O.!I PV ~
ht in~92.u.tl"tltES Vl!;ltO ,., ILAGl. ' TUltATlONA~-
I ,I
I I I RATE:O AAM.
AAT(.() fTf ti.A. CURR""" 0
I I' v SATUMTIOHA~
AAT£0.t.RMATUft
I/ curitur I I J
1.3

(o) BRUSf-. ...ESS 1Nl '-'O'J1 PLOT EXCITER
VT,..,..,,....
Power and
Ve toge
Sensln~
Main Ce"erotor
. - ·=
, '.. - . .
' -· ...
e,c.
-
Exelli:• }11.<Je
Pfole
•

(b) 8RUSHLESS I.' TH p· _QT EXCITER
Power
Voltage ~~v
Sensing
Only
Moln GE:neroto.
!>iooe
~lote
,..::::J::==JI~ 11----1

Stvtsh g
Only
(o) . CONVENllONAl
..
... ~~-;:~:..~·-.....A , "I !
. . .
d.c.
Exe tor
EXCITERS

St 1!lny
«1d Powcir
(b) STATIC
~ k:J~--------'L J
I
I
,------,I AV~
I
Cen£rctor

s,e,!O.,. g
one Po·•er
{c) l:lRUSHLESS

kVAr
kW
Cos Phi Power Factor
kVA

Both equations are multiplied by .../3 (1.732) for a 3 phase
machine.
Volts x AmpereskVA = _..;....__
1000
kVA (kilo Volt Amperes), are calculated by the formula:-
Volts x Amperes x Power Factor
kW=
1000
Kilowatts are calculated by the formula: -

The formula for calculating the Power Factor is:-
kilowatts
pf=
kVA
The Power Factor (pf), is a measure of wasted current, which is a
product of inductive loads such as motors, transformers,
(magnetic circuits), and some forms of lighting.
Power Factor

Main Rotor Windings
(disconnected from
rectifier Assembly)
Multimeter
measuring
DC Volts--
Multimeter on
10 Amp DC scale
6V
DC

Multimeter
Set to Ohms
(analogue)
or semiconductor
(digital)
+
Fig B
Fig A 1 _
Multimeter ~
-
Set to Ohms
:;-
Diode
(analogue)
under
•or semiconductor
test
(digital)
.. + [:@ +
Diode
under
test ~

20 -40 Watt/-
1 (Automobile)
Light bulb
~
+ Diode
-- 12VDC under l'.
- Battery test •
- § +
-

Insulation Tester
i- Earth (Ground)
v
Stationary I
Phase/Neutral
Output Terminals

A= Earth (ground) or chassis of Generator
B = Insulation between conductors & earth
C = Copper conductors, (windings)
P = Path of Leakage current through Insulation

1 Minute reading
P.I. = 10 Minute reading
The P.I. index is obtained by the formulae:-
Readings are taken (in Megohms) following a 1 minute and 10
minute time interval: -
A special motorised insulation tester is required, which can
maintain a test voltage of 1 - 2.5kV, (medium voltages), or 5kV,
(high voltage), for a period of 10 minutes.
The P.I. test is used as a guide to the dryness, cleanliness and
safety of the winding insulation system.
Polarisation Index Test (P.I.)

The resultant ratio is called the P.I. index, and should be a
minimum of 2 at 20°C.
A P.I. index below 1.5 suggests the windings are wet, dirty or
faulty, and should be cleaned, dried, and refurbished as
necessary.
1 Minute reading
P.I. =
10 Minute reading
The P.I. index is obtained by the formulae:-
Readings are taken (in Megohms) following a 1 minute and 10
minute time interval: -
A special motorised insulation tester is required, which can
maintain a test voltage of 1 - 2.5kV, (medium voltages), or 5kV,
(high voltage), for a period of 10 minutes.
The P.I. test is used as a guide to the dryness, cleanliness and
safety of the winding insulation system.
Polarisation Index Test (P.I.)

XX-
(F2)2VDC
ATTERY
+
Exciter
Stator
Windings
X+
(F1)

xx -
(F2)2VDC
ATTERY
+
Exciter
Stator
Windings
X+
(F1)

xx -
(F2)
X+
(F1)
Exciter
Stator
Winding
s
24 Volt
ATTERY
•
+
80ohm1A
Potentiometer

Rectifier
Diodes
Main Rotor
(4 Pole)
l
Exciter
Rotor
l

Generator
Shaft
N.D.E
Cover Stator Rotor
Housing Dowel
Stator Bolt pin

U~,.._~ .....--•---....,_~~~~
v~+-+-+-___..---.........~-..~~
w~+-+-+-----·---....1---.-4-.....~
LAMPS ROTATE BRIGHT/DIM
U~~------..~~-
v--~------.~_..-
w....+-----·---..~-+-~
U~~------..~~-
v--~------.~--~w~..........---..~......i~
LAMPS BRIGHTLAMPS DIM

P1
P1
........___.......,._ - .. -·· ... - -·-·-·-·-·-·- -·- -·
0
'C' Core
Laminated core
P2
Primary
co7uctor
P2
- - .... -·-·-·-·- ,.--'--- ......
Secondary Wincf.Jgs
s
1
52
TYPICAL DROOP
Quadrature droop equipment

Main Terminals
ws
TYPICAL DROOP C/T ON A 12 WIRE MACHINE
p

Secondary Substation
...
24/12kV
~~~~~~~~--'
CDable grid - Compact Substation -
Overhead line Polemount Transformer
Distribution Transformers
Power Plant
Typically 24 kV
Step-down
Power Transformer
420 kV
Power Transformers
' I
~~
Step-up Q :,..I-...:CJ~~

Recommended tiahtenina toraue/Nm
Bolt size Property Class
Bolt 8.8 Nut 8
MS 3,0
M6 5,5
M8 15,0
M10 30,0
M12 60,0
M16 120,0
Tightening torque

z
I I -
I I ' ' ~
I I 'It 12
I ~~
I
Zo I u,. u, ZL
i
I
I
I
'~ ,- -
. ! -
A simple equivalent diagram for the transformer can be drawn based on two measurements on the
transformer, one in no load and one in short-circuited condition.
EQUIVALENT DIAGRAM

2
1,5
1
,;
ii 0,5
M
0
-0,5
-1
t(ms)
Figure 6-13

10010
X/R
1
---i..-~
v
~
~
,,
,.,,...,
3,0
2,8
2,6
2,4
~ 2,2
.¥
2,0
1,8
1,6
1,4

Figure 10·1
2U
0
2N
0
2V
0
IUJV
00
2W
0
JW
0
Three phase transformer
1 U, 1 V, 1W, 1 N for the high voltage side and 2U, 2V, 2W, 2N for the low voltage side.
Example of a Dyn connected lransformer:

9952IAADEbyABB
Serial number Prod. year
- Phase Distribution Transformer
Rated Power kVA Cooling
Conn. Temp. Class
Frequency
Hz
lnsul Level % Total Mass kg
Impedance l'tpe of Oil 17
Pos. HV HV LV
v A v A v A
All

Av
Kva Cooling
Hz Environment Cl.
Climate Cl.
Kv Are Cl.
% lnsul. Sys. Temp "C
Kg Max. Wind. Temp •c
HV LV
v A v
Rated power (Onan)
Frequency
Connection Symbol
Insulation levels
Impedance
Total Mass
- phase
Prod. year
- Dry - Type Transformer I
Serial numb.
lndu=z.
All

Figure 6 - Separating wallsbetween transformers
Minimum fire resistance 60 min for the separating wall (El 60)
!EC 2267102
H ~ Ht (with H1 > H2)
L z 82 (with 82 > 81)

0
O row 1hrough b ush1119 (Oil flood I ype)

Conditions Protection Philosophy
Internal
Winding Phase-Phase, Differential 187T), overcurrent 151. 51N)
Phase-Ground faults Restricted ground fault protection
{87RGF)
Winding inter-turn Differential {87T), Buchholz relay,
faults
Core insulation failure. Differential {87T), Buchholz relay.
shorted laminations suddenpressure relay
Tank faults Differential {87T), Buchholz relay and
tank-ground protection
Overfluxing Volts/Hz 124)
External
Overloads Thermal {49)
Overvoltage Overvoltage 159)
Overfluxing Volts/Hz 124}
Externo I system short Time overcurrent 151, 51G).
circuits Instantaneous overcurrent 150. 50Gl

o 10 ~ ~ ~ m w ~moo m
Distance of fault from neutral
!percentage of winding)
Ground faultcurrent forimpedoncegrounded neutral transformer forfaults ot different
% of the winding.
IF
IOC
90
E-
sc" e
E e- ~
" " 700 v
E::
"' "?~ 6C
ti..,
"'c0. " SC"'0
.. ~
~ "'- .. 4()0"'
"'0
"'..c0 a.
3C~
'c ....-
" "'~ c 20"'·-
ml-a.. "'
-

Functions Typicol Product Order Code
Typical Functions 745-W2-P5-G5-Hl-T
T35-NOO-HCH-F8N-H6P-MXX-PXX-UXX-WXX
+ Harsh Environment Option 745-W2-P5-G5-Hl-T-H
T35-NOO-ACH-F8N-H6P-MXX-PXX-UXX-WXX
T60-NOO-ACH-F8N-H6P-MXX-PXX-UXX-WXX
+ Voltage and Power metering 745-W2-P5-G5-Hl-T
T35-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WXX
T60-NOO-HCH-F8l-H6P-M8N-PXX-UXX-WXX
+Directional overcurrent T60-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WXX
lockout
Stondalone HEA61-A-RU-220-X2
Integrated T35-NOO-HPH-F8N-H6P-MXX-P4l-UXX-WXX
T60-NOO-HPH-F8N-H6P-MXX-P4l-UXX-WXX
Directional overcurrent
Voltageand Power metering
67
v.s
87T Differential
86 Lockout ouxiliory
50/51 OVercurrentand short circuit
SOG Ground fault
Additional FunctionsTypical Functions
T
3Y
52
1
-•
MV.
M,V,
52
~
' '
'
JV
Transformers 750kVA and above, MV Windings

Functions Typical Product Order Code
Typical Functions 745-W3-PS-GS-Hl-T
+ Harsh Environment Option 745-W3-PS-GS-Hl-T-H
T35-NOO-ACH-F8L-H6P-MBN-PXX-UXX-WXX
T60-NOO-ACH-F8L-H6P-M8N-PXX-UXX-WXX
+Voltage and Power metering 745-W3-PS-GS-Hl-T
+Directional avercurrent T60-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WXX
Lockout
Standalone HEA61-A-RU-220-X2
Integrated T35-NOO-HPH-FBL-H6P-MBN -P4l-UXX-WXX
T60-NOO-HPH-F8L-H6P-MBN-P4L-UXX-WXX
Directional avercurrent
Voltage and Power metering
67
V.S
Additional Functions
Differential
Lockout auxiliary
Overcurrent and short circuit
(three windingsl
Neutral9round fault
(three windings!
87T
86
50/51
SON
3Y
52
3Y
52
r-1.v. 1
H.V.
or
M.V•.""--------
52
3Y
Typical FunctionsPower Transformers, Dual MV Secondary Windings

Typical Functions T60-NOO-HCH-F8N-H6P-MXX-PXX-UXX-WXX
TI5-NOO-HCH-F8N-H6P-MXX-PXX-UXX-WXX
745-WZ-PS-GS-Hl-T
+ Voltage and Power metering T60-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WXX
TI5-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WXX
745-WZ-P5-G5-Hl-T
+ Additional Functions T60-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WXX
(87G, 67. 24. 59)
745-WZ-PS-GS-Hl-R-T
lockout
Standalone HEA61-A-RU-220-XZ
Integrated T35-NOO-HPH-F8N-H6P-MXX-P4L-UXX-WXX
T60-NOO-HPH-F8N-H6P-MXX-P4L-UXX-WXX
50G
Restricted Ground Fault
Volts per Hertz
Overvoltoge
87RGF
67
24
59
V.S
Differential
lockout auxiliary
(both windings!
Ground fault
87T
86
50/51
52 -•
H,V,,.., _
or
M.11.
H.V.
52
lY
.t----------, T
Power Transformers, HV Windings

Typical Functions T60-NOO-HCH-F8l-H6P-M8N-PXX-UXX-WXX
+Voltage and Power metering T60-NOO-HCH-F8l-H6P-M8N-PXX-UXX-WXX
+Additional Functions T60-NOO-HCH-F8l-H6P-M8N-PXX-UXX-WXX
Lockout
Integrated T35-NOO-HPH-F8l-H6P-M8N-P4l-UXX-WXX
T60-NOO-HPH-F8l-H6P-M8N-P4l-UXX-WXX
Volts per Hertz
OVervoltoge
67
24
59
v.s
87RGF Restricted Ground Fault
.2Y_
52 52
_l.Y_
I I I I
~f---------.,I
I
I
H.V l a
• J
~,,,,,,
'87 ' I
2 ..'!_~..~~/-
H.V r • ,,-, ,,-, ,--,,,-, ,,-,
• ( v l s 67 86 l 59 )or I I
1/1.V.
,_,,,_,,,_,,, __,,__,
1
52 ·..:-•
-:!YI
-I
87T Differential
86 Lockout ouxirlory
50/51 Overcurrenlond short circuit
(two windings)
50G Gr-0und fault
Typical FunctionsPower Transformers, HV Windings, Dual-Breaker
Source

Typical Functions T60-NOO-HCH-F8N-H6P-MXX-PXX-UXX-WXX
lockout
Integrated T35-NOO-HPH-F8N-H6P-MXX-P4l-UXX-WXX
T60-NOO-HPH-F8N-H6P-MXX-P4l-UXX-WXX
Volts per Hertz
OVervoltoge
87RGF
67
24
59
V,S
Differential
Lockout auxiliary
(both sources)
Ground faultSOG
87T
86
50/51
>f3Y1
I
... II
I
- I
I
I
52
§.. II
' @xID9'- ,_, 'ai'' '
H,V.
',, 87T 51 250G
~~,:~)
r- ,-, ,-, ,-, ,-, ,-,, , , , ,
... ... ...... ( v l s 67 l 86 l 59 :
- - ' ,, ,, ,, ,, ,
-- -~ -- -- --,
H,V __...
•
52
>-
3Y >-
Typical FunctionsAuto-Transformer

Typical Functions T60-NOO-HCH-F8l-H6P-M8N-PXX-UXX-WXX
T3S-NOO-HCH-F8l-H6P-M8N-PXX-UXX-WXX
T3S-NOO-HCH-F8l-H6P-M8N-PXX-UXX-WXX
lockout
Integrated T3S-NOO-HPH-F8l-H6P-M8N-P4l-UXX-WXX
T60-NOO-HPH-F8l-H6P-M8N-P4l-UXX-WXX
Volts per Hertz
Overvoltoge
87RGF
67
24
59
V,S
87T Differential
86 Lockout auxiliary
50/51 Dvercurrent and short circuit
ltwo windings)
SOG Ground fault
3Y _3Y_
I '
52 52 I I
-3~--------------.., I
&' I
~,- ,_...... '87'' '
H,V
....... 2 '~~,l,~~,:
I ,,-, ,,-, ,,-, ,,-, ,,-,
• • • • l v s 67 86 l 59 ~
-- ,__,,__,,__,,_,,, __,
1
H.V.
·-·52 •
...
3Y ...
'
Typical FunctionsAuto-Transformer, Dual-Breaker Terminals

Typical Functions T35-NOO-HCH-F8l-H6P-M8N-PXX-U8N-W6P
+ Voltage and Power metering T35-NOO-HCH-F8l-H6P-M8N-PXX-UXX-W6P
lockout
Integrated T35-NOO-HPH-F8l-H6P-M8N-P4l-U8N-W6P
50/51 Overcurrent and short circuit
(three wir;idings)
SOG Ground fault
Voltage and Power meteringV.SDifferential
Lockout oUXiliory
87T
86
3Y ~r_
I I 52 52 I I
~
-3E-----------------1
@...,, :
HV
',,~
• • • •
I I r ,.,.-,,....-,3 ,,-,
- - l V S : I 86:
-- ,, ' ...,' ,__, '--"w •
HV
52
....-•
..
---
M.V
-3,Y I
52 52 I
31
-- --
Auto with Dual-Breaker on both sides and loaded
tertiary

Typical Functions T60-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WXX
Lockout
Integrated T60-NOO-HPH-F8L-H6P-M8N-P4L-UXX-WXX
Ground Faull
Volts per Hertz
Overvoltoqe
51G
24
59
V.5
Differential
Lockout auxiliary
OVercurrentand shortcircuit
(three windings)
87T
86
51
Oonorator
3'(
52
•
-52
3Y
Sy~tem
Generator Step Up Transformer

Ground fault
Top Oil Temperature, RTD or
Transducer
Winding hot-spot
temperature. loss-of-life
Thermal overload protection
Voltage and Power meteringV.S
49
SOG
rr/ro
Typical Functions T60-NOO-HCH-F8N-H6P-MXX-PXX-UXX-WSE
745-W2-PS-GS-Hl-L-T
+Voltage and Power metering T60-NOO-HCH-F8L-H6P-M8N-PXX-UXX-WSE
745-W2-PS-GS-Hl-L-T
+ Additional Functions T60-NOO-HCH-F8N-H6P-MXX-PXX-UXX-WSE
745-W2-PS-GS-Hl-L-R-T
lockout
lntegroted T60-NOO-HPH-F8N-H6P-MXX-P4l-UXX-WSE
-•
3Y
52
H.V.~---or
M.V.
86 lockout auxiliary
SO/SI Overcurrent and short circuit
(two windings}
.t--------. T
3Y
Oifferentiol
87RGF Restricted Ground Fault
Typical Functions
87T
Thermal Overload Protection

Typical Functions T35-NOO-HCH-F8N-H6P-M8N-PXX-U8N-WXX
Lockout
Integrated T35-NOO-HPH-F8N-H6P-M8N-P4L-U8N-WXX
Ground faultSOG
87T Differential
86 Lockout auxiliary
51 Overcurrent and short circuit
!two windings)
Typical Functions
1l
5252
'
)V )V
525252
"'
52 ~
6
Distribution Transformer with no load-side Circuit
Breaker

30 Motor
C1
-Transistor
L1
SCR-
L1--.
L2--1--
L3---t--11--
InverterDC LinkConverter

30 Motor
L1-----e
L2--i--
L3--<--1--
L1

L1
L2 C1 .!:?
0)
0
_J
gL3
s 30 Motor
u
L1

C1 650VDC
L1 -'--+--1-~-r--i
30, 480 VAC L2 -l,---,~1--f--tf--~
Supply
DC LinkConverter

30 Motor
u
·0i
.3
0
lo;
c
0
u
IGBT
<,
650VDC
Inverter
-f (+)

(+) 0
i i i
i A+ B+ C+
DC Voltage
MotorFrom
Converter
l J A- JB- Jc-
(-)0

. '
---:::-=--..., ·:· .. - .- --·· - -·:- - - r--~-::::'.""""-..., .+
+ :··· ....
1
....... 1· ~ :1 ·. ······:········:· .. ······1 .
0 . . . . . .
• ' • ' ' + •
. . . . . . '
: : •······~·······'.········ : : :
+ :-60°-: 1·······:········:·······1 : ~ :0 : : : : : : : :
. . . . . . .• ' ' ' • + •
. ' . ' . . ... .. . . . . ... . .. .. . ·, . . . . . . . ' . . · :
74 986532
Steps
1
A-B
Output
B
A

On
IGBTTurned '<, :/ IGBTTurned Off
~D DD I 11 I DOD~[Off
IGBTOn IGBTOn
Progressively Longer Progressively Shorter
Sine Wave Reference
Current Decreases
Current Increases

l650VDC
l
l650VDC
l
Longer "On" Duration. Higher Voltage
Shorter "On" Duration, LowerVoltage
- ...........................
~
<,
v
v r-,
/ -,
- - - - - -<,
/0-
'~ t>~
- .....

With Smoothing
Decel
T2
RunAceel
T1
. . . . . . . . . . .. ,.--1 r--...:· '
Decel
T2
Without Smoothing
14 •1:1414--H•l;l,.4-----•I;
Fmax · · · · · · · · · · · • ., __ "" 1-- ..- · · · · · · · · · · · ··
Accel Run
T1

~ Commutator
~Carbon Brush
Field Winding

/Armature Conductors
::<;:::~)
Commutator

Armature Conductor
-""'Magnetic Field
Stator
...__...__
--...-............... _ ......__..._
- .......-........_ -........................ .............. ---
-- -- ..
------------------- ~
/Magnetic Field
Electromagnet or Permanent Magnet

--------~
t··---- .
--- ------
-...._.._.. -...
..-------..--...
...._......

sN
/
Resultant Armature Field
StatorN
Static
Magnetic Field

Permanent
DMogoot
DC Line
Voltage

A
DC Line
Voltage
Series Field
S2 S1u-~ ~~

Common SourceSeparately Excited
Fl Fl
"O "O
Ql
DC Line
.!!!
DC Line u::: u,
Voltage A +-'
Voltage A +-'
c c
:J :J
s: .s:
(/) (/)
F2 F2

F1
-c.::)
s:
(/)
F2
A
DC Line
Voltage
Series Field
~-=-S=-i2 L.:S::...:1'--~

%Torque
Compound
~
] ~~~~.~..~..~.~..=..~..~.~~':"~~~~Shunt
~ Point of/
~ Equilibrium

@
SIEMENS
@
HP 10 I RPM 1180 I VOLTS 500
ARM AMPS 17.0 WOUND SHUNT
FLO AMPS 1.4/2.8 FLO OHMS 25C 156
INSUL CLASS FI DUTY CONT I MAX AMBIENT 40° c
PWRSUP
c FLO VOLTS 300/150CODE
TYPE E I ENCL DP I INSTR
MOD SER
NP36A424835AP DIRECT CURRENT
@ MOTOR
@MADE IN U.S.A

Speed (RPM)
1200900600300
o"'-~~~~~~~~~~~~
0
375 Va - (laRa)
Speed(n)=
Kt(/)
...
g
250 oru , .................. ·····
0
CEMF
Speed (n)""
(I)
125
500 ....

Compound
F1
A
F2
ShuntSeries
A
S2
Permanent
Magnet

F4
F3
F2
F1
150VDC
2.8A
F4
F1
300VDC F2
1.4 A F3

180°-
1600-
140°=
120°=
100°=
80°=
60°=
40° =~-Ambient Temperature
20°=
oo=

Class H
125° C Rise
15° C Hot Spot
Class F
105°C Rise
10°C Hot Spot
Class B
80° C Rise
10° C Hot Spot
Class A
60°C Rise
5°C Hot Spot
180°- 180°- 180°- 180°-
=}15°
160°- 160°- 160°= 160°=
140°= 140°= 140°=
=:}10°
140°=
120°= 120°= ==}10° 120°= 120°=
100°= =}50 100·= 100°=
105°
100°= 125°
80°= 80°= 80° 80°= 80°=
60°= 60° 60°= 60°= 60°=
40°= 40°= 40°= 40°=
20°= 20·= 20°= 20°=
o·= oo= o·= oo=

Va
(
Ir
i32
<I)
Eaj
Li:- Vr
A -ec:: ~
l
:J
s:
VJ
0
Armature Circuit Field Circuit
>la

Where:
Va = Applied Armature Voltage
Kt = Motor Design Constants
 = Shunt Field Flux
n = Armature Speed
la= Armature Current
Ra = Armature Resistance
Va = (Ktn) + (laRa)

Speed (RPM)
10007505002500
0
375 Va- (laRa)
Speed (n) =
~ Kt<!)
g
250u or
0
Speed (n) "'
CEMF
(()
125
500

CEMF
<l>
Ktct>
M "' la<D
Speed (n) "'
or
Va - (la Ra)
Speed(n)=
I.- Constant Torque.-1- Constant Horsepower -1
tBase Speed

500 750 1000
Speed (RPM)
2500
0
500
375
Speed (n) =
Va - (la Ra)
Kt<PIf)
-g
250
or
u
0 CEMF
Speed (n) "'

125
M,. la<P

Field Current (If)
-,
Knee of Curve

...c.A...::n.:..:o:...:d:...:e_---'+-1[:>k+ Cathode
Gate

Gate
Zero Crossing
Gate Applied Here
~

_ ___.n~--
[C
Jl~-
Rectified DC
at Cathode
Gate Current
Applied
AC Sinewave
Applied to Anode

L1
3121, 460 VAC
Variable
Supply
DC Voltage
L2 L2
L1
L3
I I
L3
I
v I

Volts RMS a Cosine Formula voe
460 VAe 0 1.00 voe = 460 x 1.35 x 1 621
460 VAC 30 0.87 voe = 460 x 1.35 x o.87 538
460 VAe 60 0.50 voe= 460 x 1.35 x o.so 310.5
460 VAe 90 0.00 voe = 460 x 1.35 x o 0
460 VAC 120 -0.50 voe= 460 x 1.35 x <-0.50) -310.5
460 VAC 150 -0.87 voe = 460 x 1.35 x <-0.87) -538
460 VAC 180 -1.00 VDC= 460 x 1 .35 x (- 1 ) -621

Average DC Voltage
as a Function of a
OVDC
-a= so-
-£21 VDC
a= 180°
OVDC
a = go•
'''.. J /<I, I /' /• /• / I I I J 1
' v v ~ ~ ., ~ ~ x ~ ~ ~...._, .._ _ .; ~ _ ..
...,.,,. .....,., ...,,........f..... '<".."<." -;<."_";'..,_'X" ..~ ~ ..:'...- ..~~
,' ,' / / / / 1 1 I I I I )
'
'
621 VDC
a = 0°

iQ)
~
::i
-0 0
Q) (/)
u: u
+-' 0
c: Q)
::i +-'
.1= <ti
(/) ~
<ti
0.
Q)
(/)
l
A
1
·,)~:;;-,>::·;:,.:-,.,: :..;>(:•::(;;-.~:(;
' )
I I I I I I
' ' '
' 't' t I J r I
/' ' /I J I / I t I I , I
.> ';.., _>..,..> v.. - > <.. )' ..
................................................ ,.
I I
I I L3~~1~~~~-'------,+----t~-.
Ra

OLT
@
MOD
PWRSlJP C
INSUL CLASS F DUTY
FLDAMPS 1.4
ARM AMPS 17.0
HP 10 RPM
SIEME
@
c
ENCL DPTYPE E

+
L1
-
...,
c
Q)
(..)
lat
....460VAC
A
....0 :::iL2
> (.)
-0
Q)
u:
L3
COSa~
Ra

=
+
Va = laRa + CEMF
Va= 0 + 450
Va= 450VDC
OVDC
Va= 1.35 x VRMS x COSa
Va= 1.35 x 460VAC x 0.7246
Va= 450VDC
450VDC
460VAC
RaGating Angle 43.56°
COSa = 0.7246
-,

+
Va = laRa + CEMF
Va= 50 + 450
Va= 500VDC
Ala
Va= 1.35 x VRMS x COSa
Va = 1.35 x 460 VAC x 0.8052
Va= 500VDC
500VDC
460VAC
50VDC
RaGating Angle 36.37°
COSa = 0.8052 ""-

4 Quadrant- 12 SCRs1 Quadrant - 6 SCRs

(Car Moving Forward (Car Moving Forward
Brake Applied) N Accelerator Applied)
CW Rotation
()
M
Braking II M =Torque
-M M
Driving Ill IV Braking
N =Speed
l) (O)MM
CCW Rotation CCW Rotation
-N
(Car Moving in Reverse (Car Moving in Reverse
Accelerator Applied) Brake Applied)

Reverse Armature Polarity or Reverse Shunt Field Polarity
+ + c =c F1
= Fl + Fl
-0 -0 -0 -0
Qi Qi Qi <!)
u: u: u::: u:::
- - - A -c c c c
::J ::J ::J ::J
s: s: s: J:.
l/) l/) l/) l/)
=
F2
c F2 F2 F2
= c
n n n

Reverse Direction
(Quadrant Ill)
Forward Direction
(Quadrant I)
F F
+ +
F
F2
F
F2
R R
li 11R
l
R
MOV MOV
R
i
R
F Fl F Fl

Motoring Ra
50VDC
+
M
ll
-
=A(.)
c
<l)M 0
~
(!)~> :J
L2 0
(.)L!)
-0
<:!"
QiM
u::L3

Braking Ra
50VDC
+
M
~
-L1
ir~
u
M 0
>L2 0
Ros0
co
Cl)
u:::
M
L3

M =Torque
N =Speed
M
-N
CW Rotation CW Rotation
() ()
M M
Braking II Driving
Driving Ill IV Braking
{:) 0 M
M
CCW Rotation CCW Rotation
N

A
Ra............................................................
Regen
Bridge
Motoring
Bridge

Va = laRa + CEMF
Va= 50 + 450
Va= 500VDC
50VDC
Ra
Va= 1.35 xVRMS x COSet
Va= 1.35 x 460VAC x 0.8052
Va= 500VDC
Regen
Bridge
Driving
BridgeGating Angle 36.37°
COSet = 0.8052
"-l
L1 450VDC
CEMF ~
~
u
...,
c
460VAC 0 Q)
> ~
L2 A
~
0 la
:J
0 u
U') -0
Qi
u:
L3

Va = laRa + CEMF
Va= -50 + 450
Va= 400VOC
450VOC
CEMF
- A
u ....c
0 Q)
>
~
A
~
0 la
::>
0 u
~ -0
.<:!!
l.L
-50VOC
Ra
Va= 1.35 xVRMS x COSa
Va = 1.35 x 460 VAC x 0.643
Va= 400VOC
460VAC
L2~~~~~..;.-1-----<1~--l----t-~--..
Gating Angle 130°
COSo. = 0.643 ---t-+--+--1--?'
L1~~~~~-'-<.----1~--l---;---9
Regen
Bridge
Motoring
Bridge

Time~

',
-.-,
',___ Dynamic Braking
---- --------- ----------·
Base Speed
Regen or Dynamic Braking at 150% Current
Maximum Speed
i

A
Ra
............................... · : :
.............................................................. ,. .
Motoring
Bridge
Regen
Bridge

-1-Phase AC Input
Calculated CEMF (Ea) Feedback
Ea =Va - (laRa)
Firing
Circuit
Current
Controller
3-Phase AC Input
Current Feedback
Speed
Controller
Ramp
Function
Generator
Speed
Ref.

-1-Phase AC Input
Firing
Circuit
.__ Sp_e_e_d_F_e_e_d_ba_c_k@-·---
Current
Controller
3-Phase AC Input
Current Feedback
Speed
Controller
Ramp
Function
Generator
Speed
Ref.

._,...,
1-Phase AC Input
Firing
Circuit
Speed
Controller
,_ Sp_e_e_d_F_e_e_d_ba_c_k©-- ---
Current Feedback
3-Phase AC Input
Ramp
Function
Generator
Speed
Ref.

-1-Phase AC Input
Firing
Circuit
Current
Controller
3-Phase AC Input
Current FeedbackUpper
' Limit /
Torque Torque
Ref. Calculation
I Lower '
Limit

INew Speed
/Initial Overshoot
/ Oscillations
Initial Speed
-.

/Initial Overshoot
Initial Speed
New Speed
I
-.

10 20
._ __ ___. ___. _.._-i> Time in Seconds
50% . - . - .... . .. . .. . . . . . .· : - .. ·.
100% ·····-··-··-·-······---41--- ...······-··-··········
P303 Run P304
M------~: ,. ., : M------~
Speed

10 20
"""'-----'------------'----3'..~ Time in Seconds
50°/o · ·· · ·· · · ·' · · · · · · · · :- · · · · · · · · ·· ; · · · ·· · · · ·· · · · ·· · - · '
. /' R di .; oun 1ng :
100% -_;;.·' ""'! !-" .;..:' ' .......•. '
P303 Run P304
H114------•I:14 •I: !+-------fol
Speed

1
T =ConstantT""N T~N T"" N2
HP = Constant HP"' N HP"' N2 HP::. N3
HP T ,
------ I/
/ /,
HP/
/ T I
T I
/ I
/ / HP T 7
/ / ,.,,.,HP/ /, ,,.. /
N N N N
Winders Hoisting gear Calenders with Pumps
Facing lathes Belt conveyors viscous friction Fans
Rotary cutting Process machines Eddy-current Centrifuges
machines involving forming brakes
Rolling mills
Planers

Cateaorv Descriotion
The load is essentially the same throughout the
Constant Torque speed range. Hoisting gear and belt conveyors
are examples.
Variable Torque
The load increases as speed increases. Pumps
and fans are examples.
Constant The load decreases as speed increases. Winders
Horsepower and rotary cutting machines are examples.
Loads generally fall into one of three categories:

Photo 3, Arcing Caused by Loose Input Contacts

Photo 4, Arcing Caused by Loose Output Contacts

Photo 2, Corrosion on Board Traces Caused by Moisture

Photo 5, Foreign Object in Fan

(a)
acb phase sequenceabc phase. sequence

(b)
Switch S1
Load
.-,
Generator 2
Generator I

P = output power
fu1 =no-load frequency of the generator
(,ys= operating frequency of system
Sp = slo e of curve in kW/Hz or MW/Hz
Where
Since mechanical speed is related to the electrical frequency and electrical frequency is related with the
out ut ower, hence we will obtain the following uation:
P=s J, " )11/ - J j s._,,.....
Typical values of SD are 2% - 4%. Most governors have some type of set oint adjustment to allow the
no-load speed of the turbine to be varied. A typical speed vs. power plot is as shown below.
Where n01 is the no-load prime mover speed and ne is the full-load prime mover speed.
n -nSD= .,,, fl x'TOO%
nil
Whatever governor mechanism is present on a prime mover, it will always be adjusted to provide a slight
droo ing characteristic with increasing load. The s eed droo SD) of a rime mover is defined as:

Power.
kV(b)
0
~·--------------I
I
I
I
I
j
I
I
I
~~I.........=-~-~-~-~-~-=---=-::_:-:_-::_:-:_::-_:::-,,_,_,__
I
I
I
I
I
I
I
I
0 Pn Power.
(a) kW
,,,,

(b)(a)
Q.
kVAI<
supplied
-Q 0
Consumed
P.
kW
supplied
-P 0
Consumed
f,

ous generator operating
with an infinite bus
Infinite bus
)
Loads
) )
'

A synchron
Generator in parallel
(a)

The frequency-power diagram
(house diagram) for a synchronous
generator in arallel with an
infinite bus.
(b)
fu1

P,kW
PG<O
(consuming)
t..Hz
P,kW

P,kW
The effect of increasing the
governor's set oint on the
house diagram

The house diagram at the moment G2 is
paralleled with the system
(b)
l'c1
~GI

kW
The effect of increasing G2 's governor
set points on the operation of the system.
-- -1- ----- --
1 j I
I I I
I I
I I
I I
I I
I I
I I
Generator 2.r,Generator I
As a result, the power-frequency curve of G2 shifts upward as shown here:
What happens ifthe governor set points of G1 are increased?
The total power P101 (which is equal to P1oad) and reactive power respectively are given by:

(d)
Qlot
kVARkYAR
The effectof increasing G2' s field
current on the operating of the
system.
Generator I Generatur2
---r------1 I
I V.,-1 I
I I I
I I I
I I I
I I I
I t I
I I I

P. real power
Prime mover lirnilField Current limit
Or
Maximum Ea limit
Q, Reactive power
Stator Current limit

Figure 2-1: Relationship between current, magnetic field strength and flux
Magnetic
flux
out (8)
3
H co Current in

/1B
V,=-NsA-
1:!.t
•
Figure 2-2: Transformer schematic
*N.1
• Pe
• 'N,,•
I •• • • • • • • • • • • • •
• •'· .

Figure 2-4: 8-H Loop
I
Energy released by
collapsing field
Energy used to
esteblish field
•
Field strength, HField strength, H
co co
Ji. Ji.... ...c c'1) '1)
~ ~
x x
::i ::i
u.. u..

THANK YOU!
For Contact
Email: arslan_engineer61@yahoo.com
LinkedIn: https://pk.linkedin.com/pub/arslan-ahmed-amin-p-e-b-sc-ee-m-sc-ee-m-b-
a/24/853/68

Lecture 2 basics of electric machines

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Lecture 2 basics of electric machines