UNIT 15
Three-Phase Salient Pole
Synchronous Generator
Three-phase power (source) is required while operating this system.
The System Transformer EM-3340-3B must be included if three-phase
220V is not available.
EM-3320-1A (Magnetic Powder Brake Unit) is replaced by EM-3320-1C
(Magnetic Powder Brake Unit), and EM-3310-1B (Three-phase Power
Supply Module) is replaced by EM-3310-1E (Three-phase Power
Supply Module). It is not acceptable to mix and match the old version
with the new version.
In other words, EM-3320-1C (Magnetic Powder Brake Unit) +
EM-3310-1E (Three-phase Power Supply Module) must be grouped
together; EM-3320-1A (Magnetic Powder Brake Unit) + EM-3310-1B
(Three-phase Power Supply Module) is the right match.
15-1
EXERCISE 15-1
Armature Resistance Measurement
OBJECTIVE
After completing this exercise, you should able to measure the armature resistance of a
three-phase synchronous generator.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
Three-phase Salient Pole Synchronous Machine
EM-3330-3A
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1E
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
1
Digital DCA Meter
EM-3310-3A
1
Digital DCV Meter
EM-3310-3B
1
Laboratory Table
EM-3380-1A
1
Experimental Frame
EM-3380-2B
or Experimental Frame
EM-3380-2A
1
Connecting Leads Holder
EM-3390-1A
1
Connecting Leads Set
EM-3390-3A
1
Safety Bridging Plugs Set
EM-3390-4A
15-2
Fig. 15-1-1
Circuit diagram for armature resistance measurement
15-3
Fig. 15-1-2
Connection diagram for armature resistance measurement
15-4
PROCEDURE
CAUTION: High voltages are present in this laboratory exercise! Do not make
or modify any connections with the power on unless otherwise specified! If any
danger occurs, immediately press the red EMERGENCY OFF button on the
Three-phase Power Supply Module.
1.
Place the Three-phase Salient Pole Synchronous Machine on the Laboratory Table.
Install the required Modules in the Experimental Frame. Construct the circuit in
accordance with the circuit diagram in Fig. 15-1-1 and the connection diagram in Fig.
15-1-2. Have the instructor check your completed circuit.
The synchronous
generator operates in wye.
2.
On the DC Power Supply Module, set the V.adj knob to the min. position (fully CCW).
3.
Sequentially turn on the 3-P Current Limit Protection Switch, Three-phase Power
Supply, and DC Power Supply Modules.
4.
Press the START button on DC Power Supply Module. Slowly turn the V.adj knob
and set the voltage E to 8 V. Record the current I displayed by the Digital DCA Meter
in Table 15-1-1. Calculate the armature resistance Ra using the equation Ra = E / 2I.
5.
Repeat step 4 for other E settings in Table 15-1-1.
6.
Sequentially turn off the DC Power Supply, Three-phase Power Supply, and 3-P
Current Limit Protection Switch Modules.
Table 15-1-1
E (V)
8V
10V
14V
Measured I and calculated Ra values
I (A)
15-5
Calculated Ra ()
Experimental Results
Table 15-1-1
E (V)
8V
10V
14V
Measured I and calculated R values
I (A)
0.14
0.18
0.25
15-6
(50-Hz power)
Calculated Ra ()
28.57
27.77
28
Experimental Results
Table 15-1-1
E (V)
8V
10V
14V
Measured I and calculated R values
I (A)
0.16
0.2
0.29
15-7
(60-Hz power)
Calculated Ra ()
25
25
24
EXERCISE 15-2
No-Load Saturation Characteristic
OBJECTIVE
After completing this exercise, you should able to demonstrate the operating characteristic
of a three-phase salient pole synchronous generator under no-load saturation condition.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
DC Permanent-magnet Machine
EM-3330-1A
1
Three-phase Salient Pole Synchronous Machine
EM-3330-3A
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1E
1
Synchronous Machine Exciter
EM-3310-1C
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
2
Digital DCA Meter
EM-3310-3A
2
Digital DCV Meter
EM-3310-3B
1
Digital RPM Meter
EM-3310-3G
or Magnetic Powder Brake Unit
EM-3320-1C
Brake Controller
1
EM-3320-1N
Digital Power Analysis Meter
EM-3310-3H
or Digital ACA Meter
EM-3310-3C
Digital ACV Meter
EM-3310-3D
1
Laboratory Table
EM-3380-1A
1
Experimental Frame
EM-3380-2B
or Experimental Frame
EM-3380-2A
1
Connecting Leads Holder
EM-3390-1A
2
Coupling
EM-3390-2A
2
Coupling Guard
EM-3390-2B
1
Shaft End Guard
EM-3390-2C
1
Connecting Leads Set
EM-3390-3A
1
Safety Bridging Plugs Set
EM-3390-4A
15-8
Fig. 15-2-1
Circuit diagram for no-load saturation test
15-9
Fig. 15-2-2
Connection diagram for no-load saturation test
15-10
PROCEDURE
CAUTION: High voltages are present in this laboratory exercise! Do not make
or modify any connections with the power on unless otherwise specified! If any
danger occurs, immediately press the red EMERGENCY OFF button on the
Three-phase Power Supply Module.
1.
Place the DC Permanent-magnet Machine, Three-phase Salient Pole Synchronous
Machine, and Digital RPM Meter on the Laboratory Table. Mechanically couple the
DC Permanent-Magnet (PM) Machine to the Three-phase Salient Pole Synchronous
Machine and the Digital RPM Meter using Couplings. Securely lock the Machine
Bases together using the delta screws. Install the Coupling Guards and the Shaft
End Guard.
2.
Install the required Modules in the Experimental Frame. Construct the circuit in
accordance with the circuit diagram in Fig. 15-2-1 and the connection diagram in Fig.
15-2-2. Have the instructor check your completed circuit.
The synchronous
generator operates in delta.
Complete this laboratory exercise as quickly as possible to avoid the rise in
temperature under load condition.
3.
Set the V.adj knob on DC Power Supply Module to the min. position. Set the voltage
control knob on the Synchronous Machine Exciter Module to the 0 position.
4.
Sequentially turn on the 3-P Current Limit Protection Switch, Three-phase Power
Supply, and DC Power Supply Modules.
5.
On the DC Power Supply Module, press the START button and slowly turn the V.adj
knob to increase the motor voltage until the generator rotates at its rated speed.
Maintain the speed through this exercise. Note: The rated speed of the generator
(Three-phase Salient Pole Synchronous Machine) is 1,800 rpm for 60-Hz power (1,500
rpm for 50-Hz power).
6.
Turn on the Synchronous Machine Exciter.
15-11
7.
On the Synchronous Machine Exciter Module, slowly turn the voltage control knob so
that the field current If (obtained from the Digital DCA Meter) is 0 A. Record the
generator output voltage Eo (obtained from the Digital Power Analysis Meter) and the
speed N (obtained from the Digital RPM Meter) values in Table 15-2-1.
8.
Repeat step 7 for other If settings listed in Table 15-2-1.
9.
Sequentially turn off the DC Power Supply, Synchronous Machine Exciter,
Three-phase Power Supply, and 3-P Current Limit Protection Switch Modules.
10. Using the results of Table 15-2-1, plot the Eo vs If curve on the graph of Fig. 15-2-3.
Table 15-2-1
If (A)
0
Eo (V)
N (rpm)
If (A)
0.16
Eo (V)
N (rpm)
Measured values of If, Eo, and N
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.18
0.2
0.22
0.24
0.26
0.28
0.3
0.1
0.15
250
Eo (V)
200
150
100
50
0.05
0.2
0.25
If (A)
Fig. 15-2-3
The Eo vs If curve
15-12
0.3
0.35
Experimental Results
Table 15-2-1
Measured values of If, Eo, and N
(50-Hz power, generator speed=1500 rpm)
0
0
1500
0.16
158.4
1500
0.02
24.3
1500
0.18
171.9
1500
0.04
40.9
1500
0.2
184.3
1500
0.06
62.5
1500
0.22
194.7
1500
0.08
84.7
1500
0.24
203.2
1500
0.1
108.1
1500
0.26
212.3
1500
Eo(V)
If (A)
Eo (V)
N (rpm)
If (A)
Eo (V)
N (rpm)
Fig. 15-2-3
The Eo vs If curve
15-13
0.12
126.9
1500
0.28
217.6
1500
0.14
141.1
1500
0.3
221.6
1500
Experimental Results
Table 15-2-1
Measured values of If, Eo, and N
(60-Hz power, generator speed=1800 rpm)
If (A)
0
Eo (V)
0
N (rpm) 1800
If (A)
0.16
Eo (V)
170
N (rpm) 1800
0.02
19.3
1800
0.18
184.7
1800
0.04
40.2
1800
0.2
198.3
1800
0.06
67.3
1800
0.22
207.7
1800
0.08
90
1800
0.24
216.5
1800
0.15
0.2
0.1
110.5
1800
0.26
225
1800
0.12
131
1800
0.28
229.7
1800
0.14
153
1800
0.3
234.5
1800
250
Eo (V)
200
150
100
50
0.05
0.1
0.25
If (A)
Fig. 15-2-3
The Eo vs If curve
15-14
0.3
0.35
EXERCISE 15-3
Short-Circuit Characteristic
OBJECTIVE
After completing this exercise, you should able to demonstrate the operating characteristic
of a three-phase salient pole synchronous generator under short-circuit condition.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
DC Permanent-magnet Machine
EM-3330-1A
1
Three-phase Salient Pole Synchronous Machine
EM-3330-3A
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1E
1
Synchronous Machine Exciter
EM-3310-1C
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
2
Digital DCA Meter
EM-3310-3A
2
Digital DCV Meter
EM-3310-3B
1
Digital RPM Meter
EM-3310-3G
or Magnetic Powder Brake Unit
EM-3320-1C
Brake Controller
1
EM-3320-1N
Digital Power Analysis Meter
EM-3310-3H
or Digital ACA Meter
EM-3310-3C
Digital ACV Meter
EM-3310-3D
1
Laboratory Table
EM-3380-1A
1
Experimental Frame
EM-3380-2B
or Experimental Frame
EM-3380-2A
1
Connecting Leads Holder
EM-3390-1A
2
Coupling
EM-3390-2A
2
Coupling Guard
EM-3390-2B
1
Shaft End Guard
EM-3390-2C
1
Connecting Leads Set
EM-3390-3A
1
Safety Bridging Plugs Set
EM-3390-4A
15-15
Fig. 15-3-1
Circuit diagram for short-circuit test
15-16
Fig. 15-3-2
Connection diagram for short-circuit test
15-17
PROCEDURE
CAUTION: High voltages are present in this laboratory exercise! Do not make
or modify any connections with the power on unless otherwise specified! If any
danger occurs, immediately press the red EMERGENCY OFF button on the
Three-phase Power Supply Module.
1.
Place the DC Permanent-magnet Machine, Three-phase Salient Pole Synchronous
Machine, and Digital RPM Meter on the Laboratory Table. Mechanically couple the
DC Permanent-Magnet (PM) Machine to the Three-phase Salient Pole Synchronous
Machine and the Digital RPM Meter using Couplings. Securely lock the Machine
Bases together using the delta screws. Install the Coupling Guards and the Shaft
End Guard.
2.
Install the required Modules in the Experimental Frame. Construct the circuit in
accordance with the circuit diagram in Fig. 15-3-1 and the connection diagram in Fig.
15-3-2. Have the instructor check your completed circuit.
The synchronous
generator operates in delta.
3.
Set the V.adj knob on the DC Power Supply Module to the min. position. Set the
voltage control knob on the Synchronous Machine Exciter to the 0 position.
4.
Sequentially turn on the 3-P Current Limit Protection Switch, Three-phase Power
Supply, and DC Power Supply Modules.
5.
On the DC Power Supply Module, press the START button and slowly turn the V.adj
knob to increase the motor voltage until the generator rotates at the its rated speed.
Maintain the speed through this exercise. Note: The rated speed of the generator
(Three-phase Salient Pole Synchronous Machine) is 1,800 rpm for 60-Hz power (1,500
rpm for 50-Hz power).
6.
Turn on the Synchronous Machine Exciter.
15-18
7.
Slowly turn the voltage control knob on the Synchronous Machine Exciter Module and
set the field current If (obtained from the Digital DCA Meter) to 0 A. Record the
generator output current Io (obtained from the Digital Power Analysis Meter) and the
generator speed N (obtained from the Digital RPM Meter) value in Table 15-3-1.
8.
Repeat step 7 for other field current If settings listed in Table 15-3-1.
9.
Sequentially turn off the DC Power Supply, Synchronous Machine Exciter,
Three-phase Power Supply, and 3-P Current Limit Protection Switch Modules.
10. Using the results of Table 15-3-1, plot the Io vs If curve on the graph of Fig.15-3-3.
Table 15-3-1
Measured values of If, Io, and N
If (A)
Io (A)
N (rpm)
If (A)
Io (A)
N (rpm)
0
0.12
0.02
0.14
0.04
0.16
0.06
0.18
0.08
0.2
0.1
0.22
1.2
Io (A)
0.8
0.6
0.4
0.2
0.05
0.1
0.15
0.2
If (A)
Fig.15-3-3
The Io vs If curve
15-19
0.25
0.3
0.24
Experimental Results
Table 15-3-1
Measured values of If, Io, and N
(50-Hz power, generator speed =1500 rpm)
If (A)
Io (A)
N (rpm)
If (A)
Io (A)
N (rpm)
0
0
1500
0.12
0.44
1500
0.02
0.088
1500
0.14
0.523
1500
0.04
0.06
0.08
0.158
0.22
0.29
1500
1500
1500
0.16
0.18
0.2
0.22
0.583
0.663
0.745
0.824
1500
1500
1500
1500
1.2
Io (V)
0.8
0.6
0.4
0.2
0.05
0.1
0.15
0.2
If (A)
Fig.15-3-3
The Io vs If curve
15-20
0.25
0.3
0.1
0.392
1500
0.24
0.896
1500
Experimental Results
Table 15-3-1
Measured values of If, Io, and N
(60-Hz power, generator speed =1800 rpm)
If (A)
Io (A)
N (rpm)
If (A)
Io (A)
N (rpm)
0
0
1800
0.12
0.5
1800
0.02
0.11
1800
0.14
0.59
1800
0.04
0.06
0.18
0.26
1800
1800
0.16
0.18
0.2
0.67
0.77
0.84
1800
1800
1800
0.08
0.34
1800
0.22
0.92
1800
1.2
Io (A)
0.8
0.6
0.4
0.2
0.05
0.1
0.15
0.2
If (A)
Fig.15-3-3
The Io vs If curve
15-21
0.25
0.3
0.1
0.43
1800
0.24
1
1800
EXERCISE 15-4
Load Characteristic
OBJECTIVE
After completing this exercise, you should able to demonstrate the operating characteristic
of a three-phase salient pole synchronous generator under load condition.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
DC Permanent-magnet Machine
EM-3330-1A
1
Three-phase Salient Pole Synchronous Machine
EM-3330-3A
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1E
1
Synchronous Machine Exciter
EM-3310-1C
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
1
Resistive Load Module
EM-3310-4R
1
Capacitive Load Module
EM-3310-4C
1
Inductive Load Module
EM-3310-4L
1
Four-pole Switch Module
EM-3310-2B
2
Digital DCA Meter
EM-3310-3A
2
Digital DCV Meter
EM-3310-3B
1
Digital RPM Meter
EM-3310-3G
or Magnetic Powder Brake Unit
EM-3320-1C
Brake Controller
1
1
EM-3320-1N
Digital Power Analysis Meter
EM-3310-3H
or Digital ACA Meter
EM-3310-3C
Digital ACV Meter
EM-3310-3D
Digital Three-phase Watt Meter
EM-3310-3E
Digital Power Factor Meter
EM-3310-3F
Laboratory Table
EM-3380-1A
15-22
1
Experimental Frame
EM-3380-2B
or Experimental Frame
EM-3380-2A
1
Connecting Leads Holder
EM-3390-1A
2
Coupling
EM-3390-2A
2
Coupling Guard
EM-3390-2B
1
Shaft End Guard
EM-3390-2C
1
Connecting Leads Set
EM-3390-3A
1
Safety Bridging Plugs Set
EM-3390-4A
15-23
Fig. 15-4-1
Circuit diagram for load characteristic test
15-24
Fig. 15-4-2
Connection diagram for load characteristic test
15-25
PROCEDURE
CAUTION: High voltages are present in this laboratory exercise! Do not make
or modify any connections with the power on unless otherwise specified! If any
danger occurs, immediately press the red EMERGENCY OFF button on the
Three-phase Power Supply Module.
1.
Place the DC Permanent-magnet Machine, Three-phase Salient Pole Synchronous
Machine, and Digital RPM Meter on the Laboratory Table. Mechanically couple the
DC Permanent-Magnet (PM) Machine to the Three-phase Salient Pole Synchronous
Machine and the Digital RPM Meter using Couplings. Securely lock Machine Bases
together using delta screws. Install the Coupling Guards and the Shaft End Guard.
2.
Construct the circuit in accordance with the circuit diagram in Fig. 15-4-1 and the
connection diagram in Fig. 15-4-2. Have the instructor check your completed circuit.
The synchronous generator operates in delta.
Complete this laboratory exercise as quickly as possible to avoid the rise in
temperature under load condition.
3.
Set the V.adj knob on the DC Power Supply Module to the min. position. Set the
voltage control knob on the Synchronous Machine Exciter Module to the 0 position.
Set the on-off switch on the Four-Pole Switch module to the OFF position. On the
Resistive Load module, set the switches S0 through S4 to ON position.
4.
Sequentially turn on the 3-P Current Limit Protection Switch, Three-phase Power
Supply, and DC Power Supply Modules.
5.
On the DC Power Supply Module, press the START button and slowly turn the V.adj
knob to increase the motor voltage until the motor rotates at its rated speed N=1,800
rpm for 60-Hz power (or 1,500 rpm for 50-Hz power). Maintain this speed through this
exercise.
6.
Turn on the Synchronous Machine Exciter.
15-26
7.
Slowly turn the voltage control knob on the Synchronous Machine Exciter to set the
generator output voltage EO to 220 V. Record the field current If in the S0-S4=ON
field of Table 15-4-1. Note: The If value must be maintained in this laboratory
exercise.
8.
In the laboratory excise, if the rotor of generator is locked by a load, turn off the
power immediately. Note: The motor (prime mover) current must not exceed
130% of the rated current. The generator current must not exceed 130% of the
rated current, 0.8A x 1.3 = 1.04A.
9.
Maintain the speed (N=1,800 rpm) and the field current I f obtained in Step 7. On the
Resistive Load module, set the switches for each of the listed positions in Table 15-4-1.
Record the generator output current Io, generator output voltage Eo, generator output
power Po, and power factor cos θ (obtained from the Digital Power Analysis Meter),
and the generator speed N (obtained from the Digital RPM Meter) values in Table
15-4-1. The “shorted” position is that the rotor windings are short-circuited by setting
the on-off switch on the Four-Pole Switch module to ON position.
10. Sequentially turn off the Capacitive Load, Inductive Load, Resistive Load, DC Power
Supply, Synchronous Machine Exciter, Three-phase Power Supply, and 3-P Current
Limit Protection Switch Modules.
11. Repeat Steps 3 through 10 for resistive and inductive loads. On the Resistive Load
and Inductive Load modules, set the switches for each of the listed positions in Table
15-4-2. Record the generator output current Io, generator output voltage Eo,
generator output power Po, and power factor cos θ (obtained from the Digital Power
Analysis Meter), and the generator speed N (obtained from the Digital RPM Meter)
values in Table 15-4-2.
The “shorted” position is that the rotor windings are
short-circuited by setting the on-off switch on the Four-Pole Switch module to ON
position.
12. Repeat Steps 3 through 10 for resistive and capacitive loads. On the Resistive Load
and the Capacitive Load modules, set the switches for each of the listed positions in
Table 15-4-3. Record the generator output current Io, generator output voltage Eo,
generator output power Po, and power factor cos θ (obtained from the Digital Power
15-27
Analysis Meter), and the generator speed N (obtained from the Digital RPM Meter)
values in Table 15-4-3.
The “shorted” position is that the rotor windings are
short-circuited by setting the on-off switch on the Four-Pole Switch module to ON
position.
13. Using the results of Tables 15-4-1 through 15-4-3, plot the Eo vs Io curves on the graph
of Fig. 15-4-3.
Table 15-4-1
Measured values of If, Io, Eo, Po, N, and cos θ
Switch Positions on Resistive Load Module
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
Shorted
220
Table 15-4-2
Measured values of If, Io, Eo, Po, N, and cos θ
Switch Positions on Resistive Load and Inductive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON Shorted
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
220
Table 15-4-3
Measured values of If, Io, Eo, Po, N, and cos θ
Switch Positions on Resistive Load and Capacitive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON Shorted
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
220
15-28
E o (V )
Fig. 15-4-3
The Eo vs Io curves
15-29
Experimental Results
Table 15-4-1
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
Measured values of If, Io, Eo, Po, N, and cos θ
( 50-Hz power )
Switch Positions on Resistive Load and Inductive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON shorted
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0.43
0
0.2
0.39
0.56
0.72
0.84
0.93
1.72
260
250
240
230
220
207
197
0
—
0
0.88
0.85
0.83
0.84
0.83
0.87
0
72
133.5
183.9
225.6
250
283.5
0
1800
1800
1800
1800
1800
1800
1800
1800
Table 15-4-3
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
( 50-Hz power )
Switch Positions on Resistive Load Module
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON shorted
0.31
0.31
0.31
0.31
0.31
0.31
0.31
0.31
0
0.13
0.27
0.41
0.54
0.67
0.78
1.24
240
233
230
224
220
210
203
0
—
0
1
1
1
1
1
1
0
57.7
114.1
164.1
213.3
248.6
281.7
0
1800
1800
1800
1800
1800
1800
1800
1800
Table 15-4-2
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
Measured values of If, Io, Eo, Po, N, and cos θ
Measured values of If, Io, Eo, Po, N, and cos θ
( 50-Hz power )
Switch Positions on Resistive Load and Capacitive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON shorted
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0.19
0
0.16
0.34
0.55
0.74
0.9
1.06
0.76
194
206
213
218
220
215
210
0
—
0
-0.64
-0.6
-0.54
-0.6
-0.6
-0.65
0
43.4
98.5
155.8
213.5
264.7
296
0
1800
1800
1800
1800
1800
1800
1800
1800
15-30
E o (V )
Fig. 15-4-3
The Eo vs Io curves
15-31
Experimental Results
Table 15-4-1
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
Measured values of If, Io, Eo, Po, N, and cos θ
( 60-Hz power )
Switch Positions on Resistive Load and Inductive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON shorted
0.52
0.52
0.52
0.52
0.52
0.52
0.52
0.52
0
0.248
0.474
0.664
0.837
0.966
1.086
1.9
257.9
244.4
233.5
221.7
212.3
197.7
186.8
0
0
0.697
0.692
0.7
0.709
0.713
0.718
0
0
73
132
178
215
235
253
0
1500
1500
1500
1500
1500
1500
1500
1500
Table 15-4-3
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
( 60-Hz power )
Switch Positions on Resistive Load Module
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON shorted
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0.36
0
0.147
0.288
0.423
0.55
0.669
0.778
1.334
235.5
232.3
228
225.4
220
213.1
206.6
0
0
0.999
0.999
0.999
0.999
1
1
1
0
59
113
166
210
247
278
0
1500
1500
1500
1500
1500
1500
1500
1500
Table 15-4-2
If (A)
Io(A)
Eo (V)
cos θ
Po (W)
N (rpm)
Measured values of If, Io, Eo, Po, N, and cos θ
Measured values of If, Io, Eo, Po, N, and cos θ
( 60-Hz power )
Switch Positions on Resistive Load and Capacitive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON shorted
0.23
0.23
0.23
0.23
0.23
0.23
0.23
0.23
0
0.167
0.34
0.536
0.713
0.888
1.025
0.874
211.1
209.8
213.6
219.6
220
219
212.6
0
0
-0.789
-0.788
-0.77
-0.77
-0.775
-0.781
0
0
47
99
158
209
262
294
0
1500
1500
1500
1500
1500
1500
1500
1500
15-32
E o(V )
Fig. 15-4-3
The Eo vs Io curves
15-33
EXERCISE 15-5
Excitation Characteristic
OBJECTIVE
After completing this exercise, you should be able to demonstrate the excitation
characteristic of a three-phase salient pole synchronous generator.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
DC Permanent-magnet Machine
EM-3330-1A
1
Three-phase Salient Pole Synchronous Machine
EM-3330-3A
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1E
1
Synchronous Machine Exciter
EM-3310-1C
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
1
Resistive Load Module
EM-3310-4R
1
Capacitive Load Module
EM-3310-4C
1
Inductive Load Module
EM-3310-4L
2
Digital DCA Meter
EM-3310-3A
2
Digital DCV Meter
EM-3310-3B
1
Digital RPM Meter
EM-3310-3G
or Magnetic Powder Brake Unit
EM-3320-1C
Brake Controller
1
EM-3320-1N
Digital Power Analysis Meter
EM-3310-3H
or Digital ACA Meter
EM-3310-3C
Digital ACV Meter
EM-3310-3D
Digital Three-phase Watt Meter
EM-3310-3E
Digital Power Factor Meter
EM-3310-3F
1
Laboratory Table
EM-3380-1A
1
Experimental Frame
EM-3380-2B
or Experimental Frame
EM-3380-2A
15-34
1
Connecting Leads Holder
EM-3390-1A
2
Coupling
EM-3390-2A
2
Coupling Guard
EM-3390-2B
1
Shaft End Guard
EM-3390-2C
1
Connecting Leads Set
EM-3390-3A
1
Safety Bridging Plugs Set
EM-3390-4A
15-35
Fig. 15-5-1
Circuit diagram for excitation characteristic test
15-36
Fig. 15-5-2
Connection diagram for excitation characteristic test
15-37
PROCEDURE
CAUTION: High voltages are present in this laboratory exercise! Do not make
or modify any connections with the power on unless otherwise specified! If any
danger occurs, immediately press the red EMERGENCY OFF button on the
Three-phase Power Supply Module.
1.
Place the DC Permanent-magnet Machine, Three-phase Salient Pole Synchronous
Machine, and Digital RPM Meter on the Laboratory Table. Mechanically couple the
DC Permanent-Magnet (PM) Machine to the Three-phase Salient Pole Synchronous
Machine and the Digital RPM Meter using Couplings. Securely lock Machine Bases
using delta screws. Install the Coupling Guards and the Shaft End Guard.
2.
Install the required Modules in the Experimental Frame. Construct the circuit in
accordance with the circuit diagram in Fig. 15-5-1 and the connection diagram in Fig.
15-5-2. Have the instructor check your completed circuit.
The synchronous
generator operates in delta.
Complete this laboratory exercise as quickly as possible to avoid the rise in
temperature under load condition.
3.
Set the V.adj knob on the DC Power Supply Module to the min. position. Set the
voltage control knob on the Synchronous Machine Exciter to the 0 position.
4.
Sequentially turn on the 3-P Current Limit Protection Switch, Three-phase Power
Supply, and DC Power Supply Modules.
5.
On the DC Power Supply Module, press the START button and slowly turn the V.adj
knob and set the prime mover to rotate at its rated speed. Maintain the speed through
this exercise. Note: The rated speed of the prime mover (DC Permanent-magnet
Machine) is 1,800 rpm for 60-Hz power (1,500 rpm for 50-Hz power).
6.
Turn on the Synchronous Machine Exciter.
15-38
7.
Slowly turn the voltage control knob on the Synchronous Machine Exciter to increase
the output voltage up to 220 V. Maintain the output voltage through this exercise.
8.
In the laboratory excise, if the rotor of generator is locked by a load, turn off the
power immediately. Note: The motor (prime mover) current must not exceed
130% of the rated current. The generator current must not exceed 130% of the
rated current (0.8A x 1.3 = 1.04A) and the field current must not exceed 130% of
the rated current (0.3A x 1.3 = 0.39A).
9.
On the Resistive Load Module, set the switch positions listed in Table 15-5-1. Record
the generator field current If (obtained from the Digital DCA Meter), generator output
current Io, generator output voltage Eo, generator output power Po, power factor cos θ
(obtained from the Digital Power Analysis Meter), and generator speed N (obtained
from the Digital RPM Meter) values in Table 15-5-1.
10. On the Resistive Load and the Inductive Load Modules, set the switch positions listed
in Table 15-5-2. Record the generator field current If (obtained from the Digital DCA
Meter), generator output current Io, generator output voltage Eo, generator output
power Po, power factor cos θ (obtained from the Digital Power Analysis Meter), and
generator speed N (obtained from the Digital RPM Meter) values in Table 15-5-2.
11. On the Resistive Load and the Capacitive Load Modules, set the switch positions listed
in Table 15-5-3. Record the generator field current If (obtained from the Digital DCA
Meter), generator output current Io, generator output voltage Eo, generator output
power Po, power factor cos θ (obtained from the Digital Power Analysis Meter), and
generator speed N (obtained from the Digital RPM Meter) values in Table 15-5-3.
12. Sequentially turn off the Resistive Load, Inductive Load, Capacitive Load, DC Power
Supply, Synchronous Machine Exciter, Three-phase Power Supply, and 3-P Current
Limit Protection Switch Modules.
13. Using the results of Tables 15-5-1 through 15-5-3, plot the If vs Io curves on the graph
of Fig. 15-5-3.
15-39
Table 15-5-1
Measured values of If, Io, Eo, Po, cos θ, and N
Switch Positions on Resistive Load Module
S0=OFF S0, S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
Io (A)
Eo (V)
cos θ
Po (W)
N (rpm)
220
Table 15-5-2
220
220
220
220
220
220
Measured values of If, Io, Eo, Po, cos θ, and N
Switch Positions on Resistive Load and Inductive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
Io (A)
Eo (V)
cos θ
Po (W)
N (rpm)
220
Table 15-5-3
220
220
220
220
220
220
Measured the values of If, Io, Eo, Po, cos θ, and N
Switch Positions on Resistive Load and Capacitive Load Modules
S0=OFF S0, S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
Io (A)
Eo (V)
cos θ
Po (W)
N (rpm)
220
220
220
220
15-40
220
220
220
0.6
0.5
0.4
If(A)
R
R-L
0.3
R-C
0.2
0.1
0.2
0.4
0.6
0.8
Io(A)
Fig. 15-5-3
The If vs Io curves
15-41
1.2
Experimental Results
Table 15-5-1
Measured values of If, Io, Eo, Po, cos θ, and N
( 50-Hz power )
Switch Positions on Resistive Load Module
S0=OFF S0, S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
0.29
0.30
0.32
0.33
0.36
0.39
0.41
Io (A)
0
0.14
0.277
0.414
0.556
0.689
0.829
Eo (V)
220
220
220
220
220
220
220
cos θ
0
1
1
1
1
1
1
Po (W)
0
53
105
157
213
262
315
N (rpm) 1500
1500
1500
1500
1500
1500
1500
Table 15-5-2
Measured values of If, Io, Eo, Po, cos θ, and N
( 50-Hz power )
Switch Positions on Resistive Load and Inductive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
0.29
0.36
0.44
0.52
Io (A)
0
0.221
0.445
0.658
Eo (V)
220
220
220
220
220
220
220
cos θ
0
0.706
0.7
0.7
Po (W)
0
60
117
176
N (rpm) 1500
1500
1500
1500
1500
1500
1500
Table 15-5-3
Measured values of If, Io, Eo, Po, cos θ, and N
( 50-Hz power )
Switch Positions on Resistive Load and Capacitive Load Modules
S0=OFF S0, S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
0.29
0.27
0.25
0.24
0.23
0.24
0.25
Io (A)
0
0.175
0.352
0.538
0.717
0.892
1.062
Eo (V)
220
220
220
220
220
220
220
cos θ
0
-0.789
-0.785
-0.78
-0.77
-0.776
-0.77
Po (W)
0
52
105
159
211
266
316
N (rpm) 1500
1500
1500
1500
1500
1500
1500
15-42
If (A)
Fig. 15-5-3
The If vs Io curves
15-43
Experimental Results
Table 15-5-1
Measured values of If, Io, Eo, Po, cos θ, and N
( 60-Hz power )
Switch Positions on Resistive Load Module
S0=OFF S0, S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
0.25
0.26
0.27
0.29
0.31
0.34
0.36
Io (A)
0
0.12
0.26
0.4
0.55
0.7
0.84
Eo (V)
220
220
220
220
220
220
220
cos θ
0
1
1
1
1
1
1
Po (W)
0
50.8
102.8
156.8
213.5
269.3
329
N (rpm) 1800
1800
1800
1800
1800
1800
1800
Table 15-5-2
Measured values of If, Io, Eo, Po, cos θ, and N
( 60-Hz power )
Switch Positions on Resistive Load and Inductive Load Modules
S0=OFF S0-S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
0.25
0.3
0.34
0.39
0.44
0.49
0.52
Io (A)
0
0.17
0.36
0.54
0.71
0.91
1.08
Eo (V)
220
220
220
220
220
220
220
cos θ
0
0.89
0.85
0.84
0.82
0.84
0.84
Po (W)
0
55.5
112
170.2
225.8
283.4
345
N (rpm) 1800
1800
1800
1800
1800
1800
1800
Table 15-5-3
Measured values of If, Io, Eo, Po, cos θ, and N
(60-Hz power )
Switch Positions on Resistive Load and Capacitive Load Modules
S0=OFF S0, S1=ON S0-S2=ON S0-S3=ON S0-S4=ON S0-S5=ON S0-S6=ON
If (A)
0.25
0.23
0.2
0.2
0.19
0.19
0.21
Io (A)
0
0.17
0.35
0.55
0.74
0.91
1.09
Eo (V)
220
220
220
220
220
220
220
cos θ
0
-0.65
-0.6
-0.6
-0.6
-0.6
-0.76
Po (W)
0
50.9
103
160.3
219
267.7
325.8
N (rpm) 1800
1800
1800
1800
1800
1800
1800
15-44
0.6
0.5
0.4
If(A)
R
0.3
R-L
R-C
0.2
0.1
0.2
0.4
0.6
0.8
Io(A)
Fig. 15-5-3
The If vs Io curves
15-45
1.2