Download UNIT 6 DC Compound Wound Motor

UNIT 6
DC Compound Wound Motor
6-1
EXERCISE
6-1 Connection and Direction Control of
DC Cumulative-Compound Wound Motor
OBJECTIVE
After completing this exercise, you should be able to demonstrate the connection of a
DC cumulative-compound wound motor and control the direction of rotation of the motor.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
DC Compound Wound Machine
EM-3330-1F
or DC Multifunction Machine
EM-3330-1B
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1B
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
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
NOTE: Though the Multifunction Machine can be used as a series, shunt, and compound
wound machine, it is inferior to individual machine in characteristics.
6-2
Fig. 6-1-1
Circuit diagram for motor direction control
6-3
Fig. 6-1-2
Connection diagram for motor direction control
6-4
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 DC Compound Wound Machine on the Laboratory Table and install the
required Modules in the Experimental Frame.
Construct the circuit in accordance with
the circuit diagram in Fig. 6-1-1 and the connection diagram in Fig. 6-1-2.
Have the
instructor check your completed circuit.
2.
Set the V.adj knob on the DC Power Supply Module to the min. position.
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 the DC Power Supply Module.
5.
On the DC Power Supply Module, slowly turn the V.adj knob to increase the motor
voltage E.
Note: The motor voltage E must not exceed the rated value of 220 Vdc.
Observe and record the direction of rotation of the motor.
The direction of rotation = _____________________
6.
Slowly return the V.adj knob on the DC Power Supply Module to the min. position.
7.
Sequentially turn off the DC Power Supply, Three-phase Power Supply, and 3-P
Current Limit Protection Switch Modules.
8.
Reverse the connecting leads to A1 and A2 terminals on the panel of the DC
Compound Wound Machine.
9.
Set the V.adj knob on the DC Power Supply Module to the min. position.
6-5
10. Sequentially turn on the 3-P Current Limit Protection Switch, Three-phase Power
Supply, and DC Power Supply Modules.
11. Press the START button on the DC Power Supply Module.
12. On the DC Power Supply Module, slowly turn the V.adj knob to increase the motor
voltage E.
Note: The motor voltage E must not exceed the rated value of 220 Vdc.
Observe and record the direction of rotation of the motor.
The direction of rotation = _____________________
13. Slowly return the V.adj knob on the DC Power Supply Module to the min. position.
14. Sequentially turn off the DC Power Supply, Three-phase Power Supply, and 3-P
Current Limit Protection Switch Modules.
6-6
EXERCISE 6-2
Torque-Speed Characteristic of
DC Cumulative-Compound Wound Motor
OBJECTIVE
After completing this exercise, you should be able to demonstrate the torque-speed
characteristic of a DC cumulative-compound wound motor.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
DC Compound Wound Machine
EM-3330-1F
or DC Multifunction Machine
EM-3330-1B
1
Magnetic Powder Brake Unit
EM-3320-1A
1
Brake Controller
EM-3320-1N
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1B
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
2
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
Coupling
EM-3390-2A
1
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
NOTE: Though the Multifunction Machine can be used as a series, shunt, and compound
wound machine, it is inferior to individual machine in characteristics.
6-7
Fig. 6-2-1
Circuit diagram for torque-speed characteristic test
6-8
Fig. 6-2-2
Connection diagram for torque-speed characteristic test
6-9
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 Compound Wound Machine, Magnetic Powder Brake Unit, and Brake
Controller on the Laboratory Table.
Mechanically couple the DC Compound Wound
Machine to the Magnetic Powder Brake Unit using a Coupling.
Machine Bases together using delta screws.
End Guard.
Securely lock the
Install the Coupling Guard and the Shaft
Electrically connect the Brake Controller to the Magnetic Powder Brake
Unit using the supplied cable.
Complete this laboratory exercise as quickly as possible to avoid the rise in
temperature under load condition.
2.
Turn the V.adj knob on the DC Power Supply Module to the min. position.
3.
Install the required Modules in the Experimental Frame.
Construct the circuit in
accordance with the circuit diagram in Fig. 6-2-1 and the connection diagram in Fig.
6-2-2.
Have the instructor check your circuit.
Note: The thermal switches of DC
Compound Wound Machine and Magnetic Powder Brake Unit must be connected
together.
Make yourself familiar with the operation of Brake Controller by referring to the
EM-3320 Operation Manual.
Before using the Brake Controller and Magnetic Powder Brake Unit, you must first
calibrate the torque display of the Brake Controller to 0 kg-m by adjusting the zero adj
knob located on the rear panel of Magnetic Powder Brake Unit with the power on.
4.
Sequentially turn on the Brake Controller, Magnetic Powder Brake Unit, 3-P Current
Limit Protection Switch, Three-phase Power Supply, and DC Power Supply Modules.
Press the START button on the DC Power Supply Module.
6-10
5.
On the DC Power Supply Module, slowly turn the V.adj knob to increase the motor
voltage E up to the rated value of 220 Vdc.
Note: The motor speed must not exceed
2,800 rpm.
6.
Manipulate the Brake Controller to operate in Mode\Closed Loop\Constant Torque
mode and set the output torque to 0 kg-m.
reboot it by pressing the RESET button.
If the Controller doesn’t operate normally,
If the rotor is locked by a heavy brake torque,
release the braking by pressing the ESC or BACK button.
7.
Record the speed N (obtained from the Brake Controller), motor current I (obtained
from the Digital DCA Meter), armature current Ia (obtained from the Digital DCA Meter),
and motor voltage E (obtained from the Digital DCV Meter) values in Table 6-2-1.
8.
Manipulate the Brake Controller to release the braking. That is to say, release the
braking by pressing the ESC or BACK button on the Brake Controller.
9.
Repeat steps 6 through 8 for other torque settings listed in Table 6-2-1.
Note: The
motor current I must not exceed 130% of the rated current, 1.65A x 1.3 = 2.145 A.
10. Slowly return the V.adj knob on the DC Power Supply Module to the min. position.
11. Sequentially turn off the DC Power Supply, Three-phase Power Supply, 3-P
Current Limit Protection Switch Modules, Magnetic Powder Brake Unit and Brake
Controller.
12. Using the results of Table 6-2-1, plot the N vs T curve on the graph of Fig. 6-2-3.
13. Using the results of Table 6-2-1, plot the I vs T curve on the graph of Fig. 6-2-4.
14. Using the results of Table 6-2-1, plot the Ia vs T curve on the graph of Fig. 6-2-5.
6-11
Table 6-2-1
Measured values of I, Ia, E, and N
T (kg-m)
I (A)
Ia (A)
E (V)
N (rpm)
0
0.05
0.1
0.15
0.2
2000
1500
1000
500
0
0
0.05
0.1
0.15
0.2
0.25
0.2
0.25
T (kg-m)
Fig. 6-2-3
The N vs T curve
2
1.5
1
0.5
0
0
0.05
0.1
0.15
T (kg-m)
Fig. 6-2-4
The I vs T curve
6-12
2
1.5
1
0.5
0
0
0.05
0.1
0.15
T (kg-m)
Fig. 6-2-5
The Ia vs T curve
6-13
0.2
0.25
EXERCISE 6-3
Speed Control of
DC Cumulative-Compound Wound Motor
OBJECTIVE
After completing this exercise, you should be able to control the speed of DC
cumulative-compound wound motor.
EQUIPMENT REQUIRED
Qty
Description
Cat. No.
1
DC Compound Wound Machine
EM-3330-1F
or DC Multifunction Machine
EM-3330-1B
1
Magnetic Powder Brake Unit
EM-3320-1A
1
Brake Controller
EM-3320-1N
1
DC Power Supply Module
EM-3310-1A
1
Three-phase Power Supply Module
EM-3310-1B
1
Three-pole Current Limit Protection Switch Module
EM-3310-2A
1
DC Motor Field Regulator
EM-3310-4B
2
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
Coupling
EM-3390-2A
1
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
NOTE: Though the Multifunction Machine can be used as a series, shunt, and compound
wound machine, it is inferior to individual machine in characteristics.
6-14
Fig. 6-3-1
Circuit diagram for speed control
6-15
Fig. 6-3-2
Connection diagram for speed control
6-16
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 Compound Wound Machine, Magnetic Powder Brake Unit, and Brake
Controller on the Laboratory Table.
Mechanically couple the DC Compound Wound
Machine to the Magnetic Powder Brake Unit using a Coupling.
Guard and the Shaft End Guard.
Install the Coupling
Electrically connect the Brake Controller to the
Magnetic Powder Brake Unit using the supplied cable.
Complete this laboratory exercise as quickly as possible to avoid the rise in
temperature under load condition.
2.
Install the required Modules in the Experimental Frame.
Construct the circuit in
accordance with the circuit diagram in Fig. 6-3-1 and the connection diagram in Fig.
6-3-2.
Have the instructor check your completed circuit.
Note: The thermal
switches of DC Compound Wound Machine and Magnetic Powder Brake Unit must be
connected together.
Make yourself familiar with the operation of Brake Controller by referring to the
EM-3320 Operation Manual.
Before using the Brake Controller and Magnetic Powder Brake Unit, you must first
calibrate the torque display of the Brake Controller to 0 kg-m by adjusting the zero adj
knob located on the rear panel of Magnetic Powder Brake Unit with the power on.
3.
On the DC Power Supply Module, set the V.adj knob to the min. position. On the DC
Motor Field Regulator, set the
4.
knob to the 0
position.
Sequentially turn on the Brake Controller, Magnetic Powder Brake Unit, 3-P Current
Limit Protection Switch, Three-phase Power Supply, and DC Power Supply Modules.
6-17
5.
Press the START button on the DC Power Supply Module.
6.
Slowly turn the V.adj knob on the DC Power Supply Module to increase the motor
voltage E up to the rated value of the motor, 220 Vdc.
Note: The motor speed
(obtained from the Brake Controller) must not exceed 2,800 rpm.
7.
Manipulate the Brake Controller to operate in Mode\Closed Loop\Constant Torque
mode and set the output torque T to 0.1 kg-m. If the Controller doesn’t operate
normally, reboot it by pressing the RESET button. If the rotor is locked by a heavy
brake torque, release the braking by pressing the ESC or BACK button.
8.
Record the motor current I (obtained from the Digital DCA Meter), the field current If
(obtained from the Digital DCA Meter), the motor voltage E (obtained from the Digital
DCV Meter), and the speed N (obtained from the Brake Controller) in Table 6-3-1.
Note: The motor current must not exceed 130% of the rated value, 1.65A x 1.3 =
2.145A.
9.
Repeat step 8 for other field resistances listed in Table 6-3-1.
10. Slowly return the V.adj knob on DC Power Supply Module to the min. position.
11. Manipulate the Brake Controller to release the braking. That is to say, release the
braking by pressing the ESC or BACK button on the Brake Controller. Turn the
knob on the DC Motor Field Regulator to the 0
position.
12. Sequentially turn off the DC Power Supply, Three-phase Power Supply, 3-P Current
Limit Protection Switch Modules, Magnetic Powder Brake Unit and Brake Controller.
13. Using the results of Tables 6-3-1, plot the N vs R curves on the graph of Fig. 6-3-3.
14. Using the results of Tables 6-3-1, plot the If vs R curves on the graph of Fig. 6-3-4.
6-18
Table 6-3-1
knob
Measured values of I, If, E, and N (T=0.1 kg-m)
0
200
400
600
800 1000 1300 1500 1800 2000 2200
220
220
220
220
220
I (A)
If (A)
E (V)
220
220
220
220
220
N (rpm)
2500
2000
1500
1000
500
0
0
500
1000
1500
2000
R( )
Fig. 6-3-3
The N vs R curves
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
0
500
1000
1500
R( )
Fig. 6-3-4
The If vs R curves
6-19
2000
220