-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
1/74
Course"EEM 41 Three-phase asynchronous machines"
Photo: ABB Group
SH5007-1E Version 1.0
Author: M.Germeroth
Lucas-Nülle GmbH · Siemensstraße 2 · D-50170 Kerpen (Sindorf)
Tel.: +49 2273 567-0
www.lucas-nuelle.de
Copyright © 2006 LUCAS-NÜLLE GmbH.
All rights reserved.
LUCAS-NÜLLE Lehr- und Messgeräte GmbHSiemensstraße 2 D-50170 Kerpen
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
2/74
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
3/74
EEM41 Drehstromasynchronmaschinen
Training objectives 1Equipment: 300W Classic Series 2
Safety 3Asynchronous motor 5Connection and starting 7Rotation reversal 17Load characteristics 23Dynamic load experiments (Classic series) 31Reactive compensation 41
Asynchronous motor, Steinmetz circuit 53Connection and starting 55Load characteristic 61
Copyright 67
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
4/74
EEM41 Drehstromasynchronmaschinen
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
5/74
EEM41 DrehstromasynchronmaschinenTraining objectives
This course is designed to convey practical know-how on the topic of three-phaseasynchronous machines.Experiment-based investigations of the asynchronous motor are the focus and coverthe functioning of the machine, its response and how it operates.
Training contents
Motor operation Nominal data, rating plate Star cnnection, delta connnection Star/delta switches Steinmetz circuit (300W series) Reactive power compensation Measurement of phase-to-phase and line-to-line values Reversal of rotation Measurement of power output with and without oad
Prerequisites
Basic knowledge of electrical machines Basic knowledge of electrical engineering Knowledge of using measuring instruments
Welcome to the Three-phase Asynchronous Machine course. The
team from LUCAS-NÜLLE wishes you lots of fun and success whileworking through the course topics and performing the experiments. Thefollowing pages provide you with an overview of the course content andthe required materials.
1
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
6/74
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
7/74
EEM41 DrehstromasynchronmaschinenSafety
Basic safety instructions
In all experiments using mains voltages high, life-threatening voltages arise. For thatreason use only safety measurement leads and make sure that there are no short-circuits.
It is imperative that all of the devices which are provided with an earthing or whereearthing is possible must be earthed. This is particularly the case for the frequencyconverter being used!
Always be very careful to check the wiring of the application modules and onlyswitch on the mains voltage after a check has been completed. Whenever possibleuse a robust current monitoring instrument in the circuit.
Always use shaft-end guards and coupling guards as protection against contactwith rotating motor parts
All locally applicable stipulations and standards governing how electrical equipmentis handled mustbe complied with.
3
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
8/74
EEM41 DrehstromasynchronmaschinenSafety
General instructions on handling the equipment
Check that the knurled screws at the base of the motor and the couplingsleves (power grip) on the motor shaft are all securely fastened. Use shaft and coupling guards. Any prolonged running of the machines when operating under high loads
can subject the machines to excessive heating. The extreme case of the machine being prevented from rotating entirely
may only arise briefly. All of the machines are equipped with a thermal circuit-breaker, which
triggers when the maximum permissible operating temperature isexceeded. These switching contacts are accessible on the terminalboard and must always be connected to the corresponding connection
sockets of the mains supply and control unit. All measurements have been recorded using conventional measuring
instruments (primarily class 1.5) at the standard mains voltage(230/400V +5% -10% 50Hz) using standard production machines.Experience suggests that measurements will lie within the tolerancerange of +/-15% with respect to the specified measurement. For moreinformation on this please refer to VDE0530.
4
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
9/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Asynchronous motors
Connection and starting Rotation reversal Load characteristics Dynamic load experiments (Classic series only ) Reactive power compensation
On the subsequent pages you will be performing the following exerciseson the "asynchronous motor":
5
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
10/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
6
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
11/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Enter the nominal data for the asynchronous machine
What is the maximum permissible voltage of the motor winding (phase voltage)?
Training content: Connection and starting
Identify the terminal connections of the motor and operate themotor as a three-phase asynchronous motor on a three-phasemains network
Utilise the nominal data of the motor based on the rating plate Measure the phase voltage and phase current Put the motor into operation in star and delta configurations Identify the differences between star and delta connections Understand the function of adelta switch Put the motor into operation with the brake Subject the motor to load
Nominal power 370_W
UN star circuit connection 690_V
UN delta circuit connection 400_V
IN star circuit connection 0,55 AIN delta circuit connection 0,95 A
cos φ 0,84
Speed 2800rpm
Frequency 50__Hz
Correct
Uphase= 400_V Correct
7
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
12/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Assembly instructions: "Connection and starting"
More detailed information on the brake can be found in the corresponding onlinedocumentation
Circuit diagram "connection & starting" (star configuration)
Assemble the circuits as specified in the following circuit diagram andset-up instructions Switch on the brake too. This does not yet subject the motor to any load
8
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
13/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Connection & starting" (star configuration)
Putting the asynchronous motor into operation in star configuration
Required settings:
Brake mode: "Torque Control"
9
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
14/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Experiment procedure:
Put the motor into operation and observe its response Brake the motor down to its nominal speed At the same time measure the phase variables Uphase and Iphase
Make sure that the ammeter and voltmeters have been connected properly
What do you measure the phase variables Uphase and Iphase to be?
Uphase= 226_VIphase= 0,31 A
Correct
10
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
15/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Circuit diagram "Connection & starting" (delta connection)
11
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
16/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Connection & starting" (delta connection)
Putting the asynchronous motor into operation in delta configuration
Required settings:
Brake mode: "Torque Control"
Experiment procedure:
Put the motor into operation and observe its response Brake the motor down to its nominal speed At the same time measure the phase variables Uphase and Iphase
Make sure that the ammeter and voltmeters have been connected correctly
12
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
17/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
What do you measure the phase variables Uphase and Iphase to be?
Circuit diagram "Connection & starting" (star and delta switch)
Uphase= 392_V
Iphase= 0,55 ACorrect
13
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
18/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Connection and starting" (star and delta switch)
Putting the asynchronous motor into operation with a star/delta switch andrecording the load characteristics
Required setting:
Brake mode: "Torque mode"
Experiment procedure:
One load characteristic each is to be recorded for the star and delta circuits Subject the motor to the load torques as given in the table Enter the measured values (M, n, Uphase, Iphase) into the tables
14
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
19/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Table1 (star connection)
Table2 (delta connection)
M/Nm 0 0,1 0,3 0,5 0,7 0,9n/(1/min) 2940 2910 2830 2720 2570 2270
Ustr/V 225 225 225 225 225 225
Istr/A 0,16 0,19 0,27 0,38 0,52 0,75
0,0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 1,1 1,2M/Nm
0
200
400
600
800
1000
12001400
1600
1800
2000
2200
2400
2600
2800
3000
n / ( 1 / m i n )
0
50
100
150
200
250
U s t r
0,0
0,1
0,2
0,3
0,4
0,5
0,60,7
0,8
0,9
1,0
1,1
1,2
1,3
1,4
1,5 I s t r
M/Nm 0 0,5 1 1,5 2 2,5
n/(1/min) 2980 2920 2850 2770 2650 2460
Ustr/V 392 392 392 392 392 392
Istr/A 0,53 0,6 0,77 1,02 1,34 1,79
0,0 0,2 0,4 0,6 0,8 1,0 1,2 1,4 1,6 1,8 2,0 2,2 2,4 2,6 2,8 3,0
M/Nm
0
200
400
600
800
1000
1200
1400
1600
1800
2000
22002400
2600
2800
3000
n / ( 1 / m i n )
0
50
100
150
200
250
300
350
400
U s t r
0,0
0,3
0,6
0,9
1,2
1,5
1,8
2,1
2,4
2,7
3,0 I s t r
15
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
20/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Which of the statements below are true?
gfedc The maximum torque of the motor is identical forboth circuit types
gfedcb In star configuration the phase current is lower
gfedcb A delta connection offers the better speed/torqueratio as compared to a star circuit
gfedcb The starting current is generally lower for the starconnection than delta configuration
gfedc The star/delta switch has practically no significanceat all
gfedcb The star/delta switch permits the motor to start "moresmoothly"
gfedc In practice asynchronous motors are operated only instar configuration
Correct
16
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
21/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Definition of rotation directionIf you look at the drive shaft end of the asynchronous machine from the perspectiveof the working machine (in our case the brake), the rotating direction is positivewhen it is clockwise. If the motor has two workable shaft ends, then it is the shaft
end opposite the cooling vents, collector or slip-rings that is the shaft end whichdefines the rotation direction.
Note: in the "Classic series" (0.3 KW & 1.0 KW) the rotation direction isdetermined by the rotation direction of the brake, i.e. if the asynchronous machinerotates clockwise, i.e. in the positive direction, the control unit of the brake indicatesa negative rotation direction. Thus the rotation direction displayed is always that ofthe brake.
Training content: "Rotation reversal"
Identify the difference between clockwise and anti-clockwiserotation
Put the motor into operation in both rotation directions
17
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
22/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Assembly instructions: "Rotation reversal"
More detailed information on the brake can be found in the corresponding onlinedocumentation
Circuit diagram "Rotation reversal" (star/delta switch)
Assemble the circuits as specified in the circuit diagrams and set-upinstructions below. Switch on the brake too. This does not yet subject the motor to any load.
18
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
23/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up for "rotation reversal" (star/delta switch)
Rotation reversal
Experiment procedure:
Switch on the motor and observe how it responds
What is the motor's direction of rotation?
nmlkji The motor rotates clockwise
nmlkj The motor rotates anti-clockwiseCorrect
19
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
24/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Switch the motor off and modify the circuit according to the following circuitdiagram
Turn the motor back on and observe its response again
Circuit diagram "Rotation Reversal" (star-delta switch)
20
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
25/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
What is the motor's direction of rotation
How can the rotation direction of the three-phase asynchronous machine bereversed?
nmlkj The motor rotates clockwise
nmlkji The motor rotates anti-clockwiseCorrect
nmlkji Interchanging any two phase lines
nmlkj Only by exchanging phase lines L2 & L3Correct
21
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
26/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
22
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
27/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Assembly instructions: "Load characteristics"
More detailed information on the brake and the software used can be found in theappropriate online documentation
Training contents: "Load characteristics"
Record the load characteristics of the motor Determine the nominal torque Determine the highest degree of efficiency Study how the motor responds to loads
Assemble the circuits as specified in the following circuit diagram andset-up instructions.
Switch the brake on too. This does not yet subject the motor to any load.
23
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
28/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Circuit diagram "Load characteristics" (star-delta switch)
24
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
29/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Load characteristics" (star-delta switch)
Recording the motor's load characteristics with the aid of the "ActiveDrive/ActiveASMA" software
Required settings:
Brake: Industrial series: "PC mode" Classic series: "Application mode" ( Note: when starting the
"ActiveASMA" software you will be prompted to select "Application
mode")
25
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
30/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Experiment procedure: Start the "ActiveDrive/ActiveASMA" software Select the operating mode "automatic speed control" Apply the brake to the motor in 20 discrete steps until the motor ceases
to turn ( Note: in the "ActiveDrive / ActiveASMA" software enter thecorresponding number of steps before this occurs under "Settings" ->"Presets" -> "Ramp")
The load characteristics of the asynchronous motor are to be recorded for bothstar as well as delta connection
Begin with a star connection For each operating mode two graphs are plotted Label and scale the graphs as shown in the place holders below The following parameters are to be recorded:
In the first graph: Torque M(n) Slip s(n) ( Note: in the "ActiveDrive / ActiveASMA" software
enter the corresponding number of steps before this occurs under"Settings" -> "Presets" -> "Machine")
In the second graph: Mechanical power P2(n)
Power factor cosφ(n) Efficiency η(n)
After completing the measurement, export the plotted graph and copy it inplace of the placeholder below
Determine the the highest possible efficiency η(n) for each operating modebased on the second graph
26
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
31/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Placeholder for the load graph (star connection); M(n); s(n)
Placeholder for load graph (star connection);
P2(n); cosφ(n) ;η(n) (η => "eta")
27
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
32/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Placeholder for load graph (delta connection); M(n); s(n)
Placeholder for load graph (delta connection);
P2(n);cos φ(n); η(n) (η => "eta")
28
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
33/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
What is the efficiency of the asynchronous machine in star configuration at
nominal speed?
What is the torque of the asynchronous machine at nominal speed in starconfiguration?
What is the efficiency of the asynchronous machine in delta configuration atnominal speed?
What is the torque of the asynchronous machine at nominal speed in deltaconfiguration?
η = 45__% Correct
MN = 0,4_Nm Correct
η = 63__% Correct
MN = 1,4_Nm Correct
29
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
34/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
30
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
35/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Assembly instructions: "Dynamic load experiments (Classicseries)"
More detailed information regarding the brake and the software being used canbe found in the corresponding online documentation
Training content: "Dynamic load experiments"
Simulate different dynamic loads (load machines) with the"DynAMA" software
Set the software parameters using the load specific default values(inertia and load torque, load constants, etc.)
Record and evaluate the various load characteristics Study how the motor responds to different loads
Assemble the circuits as specified in the following circuit diagram andset-up instruction.
Switch the brake on. This does not yet subject the motor to any load.
31
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
36/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Circuit diagram "Dynamic load experiments"
32
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
37/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Load characteristics" (star-delta switch)
33
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
38/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Generating different dynamic loads using the "DynAMA" software
Recording characteristics in star and delta starting with the "Flywheel" loadmachine
Required settings:
Brake: "Application mode" ( Note: when starting the "DynAMA" softwareyou will be prompted to select "Application mode")
The following settings are to made in "DynAMA": Load machine: "Flywheel" Moment of inertia: "10" Measurement time:"50" (seconds) Trigger: "Speed"
Level: "4" Delay: "4"
Experiment procedure:
Start the "DynAMA" software and make the required settings Label and scale the graphs as shown in the placeholders below The following parameters should be recorded during the measurement:
Speed n(t)
Torque M(t) Conductor current I(t) Start the motor first in star configuration and then, at a certain switchover
speed, the motor is switched to delta configuration A total of 3 start characteristics should be recorded for the following switchover
speeds: n1=500 rpm
n2=1000 rpm n3=1500 rpm
After completing the measurements the plotted graphs should be exportedand copied into the placeholders below
Note: during the measurement monitor the actual speed being displayed in"DynAMA" in order to perform switchover at the right point in time
Additional information on the "Flywheel" load machine and on the definition ofmoment of inertia can be found in the online documentation of the "DynAMA"software
34
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
39/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Placeholder for starting characteristic (n1=500 rpm)
Placeholder for starting characteristic (n2=1000 rpm)
35
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
40/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Placer for the starting characteristic (n3=1500 rpm)
Which of the following statements about the plotted graphs are correct?
gfedcb The magnitude of the surge in motor current isdependent on the respective switchover speed
gfedc The switchover from star to delta should always beperformed in this experiment when a max. of 15% ofthe nominal speed has been reached
gfedc The starting current drops as the moment of inertiaincreases
gfedcb When starting in star configuration, this considerablyreduces the motor's starting current
gfedc In practice there are no loads which correspond tothe speed/torque characteristic of a flywheel
Correct
36
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
41/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Recording characteristics during star-delta starting with the "Calender" loadmachine
Required settings:
Brake: "Application mode" ( Note: when starting the "DynAMA" softwareyou will be prompted to select "Application mode")
The following settings should be made in the "DynAMA" software: Load machine: "Calender" Load constant 1: "4" (1st measurement) Load constant 2: "6" (2nd measurement) Measurement time:"5" (seconds) Trigger: "Speed"
Level: "4" Delay: "4"
Experiment procedure:
Start the "DynAMA" software and make the required settings Label and scale the graphs as in the appropriate placeholders below The following parameters should be recorded during the measurement:
Speed n(t) Torque M(t)
Conductor current I(t) First start the motor in star configuration and then switch over to delta
configuration after 2 seconds A total of 2 starting characteristics should be recorded for 2 load constants:
L1= 4 L2= 6
After completing each of the measurements export the plotted graphs andcopy them into the placeholders below
Additional information regarding the load machine and on the definition of loadconstants can be found in the online documentation of the DynAMA software
37
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
42/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Placeholder for starting characteristic (L1=4)
Placeholder for starting characteristic (L2=6)
38
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
43/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Which of the following statements about the plotted graphs are correct?
gfedc There is severe delay before the increase in speed
gfedcb Only when the speed is no longer varying shouldswitchover from star to delta take place as otherwiseunnecessarily high motor currents can be producedwith this load machine
gfedc The switchover point from star to delta is arbitrarysince the load increases linearly with the speed
gfedcb After some time the speed no longer varies butremains constant
gfedc The smaller the load constant, the greater the motorcurrent at the moment of switchover
gfedcb The speed is lower in star configuration than in deltaconfiguration
Correct
39
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
44/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
40
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
45/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Assembly instructions: "Reactive power compensation"
More detailed information regarding the brake can be found in the correspondingonline documentation
Training content: "Reactive power compensation"
Understand the purpose of reactive power compensation Recognise the influence of the connection configuration ( Y- or ∆
configuration) and the effect of the capacitance on reactivepower compensation
Assemble the circuits as specified in the following circuit diagrams andset-up instructions.
Switch on the brake too. This does not yet subject the motor to any load.
41
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
46/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Circuit diagram "Reactive power compensation" (star connection with compensation)
42
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
47/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Reactive power compensation" (star connection with compensation 0.5 µF)
43
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
48/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Reactive power compensation" (star connection with compensation 1.0 µF)
Recording a load characteristic for the motor in star configuration with
compensation (0.5/1.0 µF) using the "ActiveDrive/ActiveASMA" software
Required settings:
Industrial series: "PC mode" Classic series: "Application mode" ( Note: when starting the software
"ActiveASMA" you will be prompted to select "Application mode")
44
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
49/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Experiment procedure:
Start the "ActiveDrive/ActiveASMA" software Select "Automatic speed control" operating mode The brake should be applied to the motor in 20 steps until the motor can no
longer rotate ( Note: enter the corresponding number of steps in the"ActiveDrive/ActiveASMA" software under the "Settings" -> "Presets" ->"Ramp")
Record a load characteristic for the asynchronous motor in star configurationwith various reactive power compensation levels
Begin with a compensation of 0.5 µF A separate graph is to be plotted for each compensation Label the graphs as in the placeholders below The following parameters are to be recorded:
Apparent power S(n) Active power P1(n) Reactive power Q(n) Power factor cos φ(n)
After completing the measurements the graphs plotted should be exportedand copied into the appropriate placeholders below
Placeholder for load graph; compensation 0.5 µF
45
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
50/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Placeholder for load graph; compensation 1.0 µF
46
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
51/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Circuit diagram "Reactive power compensation" (delta connection with compensation)
47
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
52/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Reactive compensation" (Delta connection with compensation 0.5 µF)
48
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
53/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Set-up "Reactive power compensation" (delta connection with compensation 1.0 µF)
Recording a load characteristic for the motor in delta configuration withcompensation (0.5/1.0 µF) using the "ActiveDrive/ActiveASMA" software
Required settings:
Brake: Industrial series: "PC mode" Classic series: "Application mode" ( Note: when starting the
"ActiveASMA" software you will be prompted to select "Applicationmode")
49
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
54/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Experiment procedure:
Start the "ActiveDrive/ActiveASMA" software Select "Automatic speed control" operating mode The brake is to be applied to the motor in 20 discrete steps until the motor is
no longer able to rotate ( Note: enter the corresponding number of steps ittakes for this to occur into "ActiveDrive/ActiveASMA" under "Settings" ->"Presets" -> "Ramp")
Record a load characteristic for the asynchronous motor in delta configurationwith various reactive power compensation levels
Begin with a compensation level of 0.5 µF For each compensation level a separate graph is to be plotted Label the graphs as shown in the placeholders below The following parameters should be recorded:
Apparent power S(n) Active power P1(n) Reactive power Q(n) Power factor cos φ(n)
After completing the plots export the graphs and copy them into thecorresponding placeholders below
Placeholder for load graph; compensation 0.5 µF
50
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
55/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
Placeholder for load graphs; compensation 1.0 µF
For which connection type is a higher reactive power compensation achieved?
What effect does the capacitance of the capacitors have on the performance?
nmlkj Star connection
nmlkji Delta connectionCorrect
gfedc None
gfedcb When the capacitors are too large the capacitivereactive power is tapped from the mains
gfedc An oversized capacitor reduces the capacitive loadon the mains and for that reason tends to bedesirable
gfedcb In general the following holds true: the lower thecapacitance of the capacitors, the worse the reactivepower compensation
Correct
51
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
56/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor
52
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
57/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Asynchronous motor, Steinmetz circuit
Connection and starting Load characteristics
On the subsequent pages you will be performing the following exerciseson the asynchronous motor with a Steinmetz circuit:
53
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
58/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
54
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
59/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Assembly instructions: "Connection and starting"
More detailed information regarding the brake and the software can be found inthe appropriate online documentation
Training contents: "Connection and starting"
Identify the motor terminals and operate the three-phaseasynchronous motor using the Steinmetz circuit from a single-conductor mains (AC power mains)
Measure the phase voltage and the phase current Examine the attributes of the Steinmetz circuit with various
operating capacitors (capacitances) Put the motor into operation with the brake Subject the motor to loads
Assemble the circuits as specified in the following circuit diagrams andset-up instructions.
Switch on the brake too. This does not yet subject the motor to any load.
55
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
60/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Circuit diagram "Connection and starting" (Steinmetz circuit)
56
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
61/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Set-up "Connection and starting" (Steinmetz circuit, C B = 6µF)
Putting the three-phase asynchronous motor into operation on the AC mainswith the aid of an operating capacitor (CB=6µF)
Required settings:
Brake mode: "Torque control"
Experiment procedure:
Put the motor into operation and observe how it responds Apply the brake to the motor until the motor reaches the nominal speed At the same time measure the phase winding voltage and
current variables Uphase, Iphase and the required braking torque MBrake
Make sure that the ammeter and voltmeter are connected correctly
57
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
62/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Enter your measurements
Set-up "Connection and starting" (Steinmetz circuit, C B = 3µF)
Uphase = 227_V
Iphase = 0,74 A
MBrake = 0,27Nm
Correct
Now reduce the capacitance of the operating capacitor by modifying the
set-up as shown below.
58
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
63/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Experiment procedure:
Put the motor back into operation and observe how it responds
How does the motor respond?
Which of the following statements are true?
nmlkj There is a severe delay before the motor startsto rotate
nmlkji The motor does not startCorrect
gfedcb Due to the lower capacitance of the operatingcapacitor, sufficient current cannot be induced and
for that reason the motor does not startgfedc The size of the operating capacitor is irrelevant to the
starting response of the motor
gfedcb The greater the capacitance the higher the startingtorque
gfedc Of course the size of the capacitor determines therotation direction of the asynchronous motor
gfedcb The torque of the three-phase motor connected to an AC mains is considerably lower than one connectedto a three-phase mains
Correct
59
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
64/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
60
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
65/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Assembly instructions: "Load characteristics"
More detailed information on the brake and the software can be found in theappropriate online documentation
Training contents: "Load characteristics"
Record the load characteristics of the motor Compute the nominal torque Determine the highest degree of efficiency Study how the motor responds to loads
Assemble the circuits according to the following circuit diagram and set-up instructions.
Switch on the brake too. This does not yet subject the motor to any load.
61
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
66/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Circuit diagram "Load characteristics" (Steinmetz circuit)
62
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
67/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Set-up "Load characteristics " (Steinmetz circuit, C B = 6µF)
63
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
68/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Required settings:
Brake: "PC mode" or "Application mode" ( Note: when starting the"ActiveASMA" software you will be prompted to select "Application mode")
Experiment procedure:
Start the "ActiveDrive/ActiveASMA" software Select "Automatic speed control" operating mode The brake is applied to the motor in 20 discrete steps until a speed of 1200
rpms is reached ( Note: enter the corresponding number of steps it takes toachieve this in the "ActiveDrive/ActiveASMA" software under "Settings" ->"Presets" -> "Ramp"!)
Record load characteristics for the asynchronous motor on an AC mains A total of two graphs are to be recorded Label and scale the graphs as in the appropriate placeholders shown below The following parameters are to be recorded:
In the first graph: Torque M(n) Degree of efficiency η(n)
In the second graph: Mechanical power P2(n) Apparent power S(n)
Active power P1(n) Reactive power Q(n) After completing the measurement export the plotted graphs and copy them
into the appropriate placeholders below
64
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
69/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Placeholder for load graph; M(n); η(n) (η => "eta")
Placeholder for load graph; P2(n); S(n); P1(n); Q(n)
65
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
70/74
EEM41 Drehstromasynchronmaschinen Asynchronous motor, Steinmetz circuit
Based on the first graph determine the efficiency for the nominal speed
η = 31__% Correct
66
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
71/74
EEM41 DrehstromasynchronmaschinenCopyright
Copyright © 2004-2006 LUCAS-NÜLLE GmbH.
This course "EEM 41 Three-phase asynchronous machines" is protected bycopyright. All rights pertaining thereto are reserved. Any reproduction of thedocument as a file or in written form be it photocopy, microfilm or any other methodor conversion into a machine-compatible language, in particular for data processingsystems, without the expressed written approval of the LUCAS-NÜLLE GmbH isstrictly forbidden.
The software as described above is made available on the basis of a generallicensing agreement or in the form of a single license. The use or reproduction of thesoftware is only permitted in strict compliance with the contractual terms stated
therein.
If changes have been performed in a manner which was not strictly authorised bythe LUCAS-NÜLLE GmbH, any product liability or warranty claims pertaining theretoare null and void.
Congratulations! This is the last page. You have completed the course "EEM41 Three-phase asynchronous machines".
67
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
72/74
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
73/74
-
8/9/2019 SH5007-1E Máquinas Trifásicas Asincronas Profesor Ingles.pdf
74/74
16
Lucas-Nülle Lehr- und Meßgeräte GmbH
Siemensstraße 2 · D-50170 Kerpen-Sindorf
Telefon +492273567-0 · Fax +49 2273567-30
www.lucas-nuelle.de