Motors

Concept

Both three-phase synchronous motors and three-phase asynchronous motors can be driven with the servo drives from the AX5000 series. Due to this flexibility, it is possible to implement inexpensive drive solutions with asynchronous motors in addition to demanding positioning tasks in the shortest possible time. The operation of asynchronous motors with the AX5000 is useful if, in the configuration of the drive system, a channel is still freely available and more asynchronous motors are used that are to be operated with open-loop control. In the case of the use of asynchronous motors intended for closed-loop operation, the AX5000 series is a good alternative regardless of the configuration of the drive system.

Motor data set

A motor data set contains the motor data required by the AX5000 to operate the motor. Motor data sets are saved in a so-called motor database. Beckhoff is continually expanding the pool of available motor data sets and makes the latest motor database available automatically when the TwinCAT Drive Manager is updated.
If you create motor data sets yourself, you create a separate structure and remain independent of the motor database. This means that your motor data sets are retained even if the motor database is expanded by Beckhoff.

TwinCAT Drive Manager

The selection of motors or the input of the parameters for new motors takes place via the TwinCAT Drive Manager (TCDM). The screen masks required for the parameterisation will be explained at this point. If you need basic information about the TCDM, please read the complete documentation, which is available on our website for download.

Start the TCDM and click the entry (2) under the relevant channel (1) in the tree; the motor/feedback configuration appears in the TCDM working area. Click on the field (3) in order to open the ‘Motor selection window’. In the ‘Motor selection window’ you can display all of the available motors or enter your own motors including motor parameters (asynchronous motors only).

Synchronous motors

In the case of synchronous motors, you can only select an existing motor; it is not possible to register your own motors. If your motor is not listed, please contact our support department.

Asynchronous motors

With the AX5000 you have the possibility to implement a good positioning drive with an inexpensive standard motor in combination with a low-cost incremental encoder.

Linear

Linear asynchronous motors are not supported at present.

Rotational

General

In the following diagram you will find various curves related to the speed range of an asynchronous motor driven by a converter.

1. Motor selection

You can either choose an existing motor (1) or generate parameters for a new motor (2). After selection, click ‘OK’ (3) to move to the next menu.

2. Identifying motor data

Identifying motor data are entered or selected in the next menu. Expert mode (9) is not currently supported. Parameters (4) and (5) are preset; you do not need to change them. You can enter a new motor manufacturer or select an existing motor manufacturer in parameter (6). A new group is generated in parameter (7) to suit the motor. If you wish to conform to the structure of the motor database, name the group according to the nominal speed of the motor. Enter the exact type of designation of the motor in parameter (8). Check your entries and then click ‘Next’ (10) to move to the next menu.

3. Basic motor data

The basic data are subdivided into three categories: ‘Basic’ (1); ‘Temperature:’ (2) and ‘Brake’ (3).

Basic (1):

a) Type of connection: Star or delta connection. If you wire and operate the motor in a star or delta configuration, please note that the rated motor current changes along with the rated motor voltage and that the AX5000 can supply a maximum rated voltage of 480 V. Please refer to the motor documentation or name plate for the permissible motor voltages and currents for star and delta connection.

b) The derating is dependent upon your application. Derating is the difference between the effective rated channel current and the rated motor current in %.  Example: rated motor current = 4 A; effective rated channel current = 3 A -> derating = 25 %.

c) The ratio of Ip to In (overload factor) is set to 1.5 as standard and must be checked against the motor documentation or name plate.

d) The rated current must be adjusted in accordance with the type of connection and checked against the motor documentation or name plate.

e) The maximum motor speed is dependent upon the mechanical properties and the maximum rotary field frequency of the AX5000. Please observe the M / f curve and the field weakening according to the motor documentation.

f) The rated voltage must be adjusted in accordance with the type of connection and checked against the motor documentation or name plate.

g) The nominal speed is dependent upon the number of pole pairs and the nominal frequency and must be checked against the motor documentation or name plate.

h) The nominal frequency is set to 50 Hz as standard and must be checked against the motor documentation or name plate.

i) The power factor (cos y) is set to 0.8 as standard and must be checked against the motor documentation or name plate.

Temperature (2):

k) The type of motor temperature monitoring used and the AX5000 input used must be selected:

• 0 = switch to X14 or X24
• 1 = KTY 83-110 to X14 or X24
• 2 = switch to X12 or X22
• 3 = KTY84-130 to X14 or X24

If the combination you have used is not included in the list, please contact our support department.

m) The temperature at which a warning is given is set to 80 °C. This parameter is effective only for KTY sensors.

n) The temperature at which the motor is switched off is set to 140 °C and must be checked against the motor documentation or name plate. This parameter is effective only for KTY sensors.

Brake (3)

o) The type of motor brake used must be selected and checked against the motor documentation or name plate.

Double-check all entries and click ‘Next’ (4) to move to the next menu.

4. Summary

The motor data entered, and the data calculated from them are displayed in this window. Please check ALL parameters once more for plausibility and click ‘OK’ (5) to move to the next menu.

5a. Default storage folder for self-generated motor data sets

The default storage folder for self-generated motor data sets is called ‘CustomerGenerated’ (1) and the suggested file name (2) corresponds to the type of motor entered above (see 2. ‘Identifying motor data’, above). This storage folder has the advantage that you can find your self-generated motor data sets briefly; however, they are not included in the above list above under 1. ‘Motor selection’ but are only visible if you click the ‘Load’ button at the bottom right under 1. ‘Motor selection’. The suggested name designates only the XML file of the motor data set. For the purposes of displaying in the lists, the XML file is read and the corresponding identifying motor data (‘Vendor’, ‘Motor group’ and ‘Motor type’) are listed as a selection.
To save your data, click on ‘Save’ (4), which then takes you to the last menu.

If your self-generated motor data sets are to be listed directly in the above list under 1. ‘Motor selection’, click on the symbol (3) to open the 'MotorPool’ folder.

5b. Default storage folder for the motor data sets from the Beckhoff motor database

The default storage folder for the motor data sets provided is called ‘MotorPool’ (4). All motor data sets from the Beckhoff motor database are located here in the form of XML files. We recommend that you assign a unique file name to your self-generated motor data set, so that you can identify it (5):
Customer = name of your company
Mototec = The name (Vendor) assigned by you under 2. ‘Identifying motor data’
3000 = The motor group assigned by you under 2. ‘Identifying motor data’
17K456FGH = The motor type assigned by you under 2. ‘Identifying motor data’

Of course, you can also assign an arbitrary file name. The assigned name designates only the XML file of the motor data set. For the purposes of displaying in the lists, the XML file is read and the corresponding identifying motor data (‘Vendor’, ‘Motor group’ and ‘Motor type’) are listed as a selection.

You create one XML file for each motor data set; the motors from the same motor group of a manufacturer (Vendor) are always summarized in the XML files for Beckhoff motor data sets.

To save your data, click on ‘Save’ (6), which then takes you to the last menu.

6. Mains voltage and further settings

This window also appears when you select an existing motor data set (synchronous motor or asynchronous motor). You can adapt the following entries at any time.

a) You can select one of the pre-defined mains voltage variants or you can specify one of your own.

b) Enter the mains voltage (only possible if no voltage was selected in a)).

c) Enter the upper tolerance of the mains voltage (only possible if no voltage was selected in a)).

d) Enter the lower tolerance of the mains voltage (only possible if no voltage was selected in a)).

e) & f) Phase monitoring is only useful for a 3-phase mains supply. Switch phase monitoring on or off (only possible if no voltage was selected in a)).

g) Use this setting to enable automatic transfer of the resolution of the encoder and the scaling factor from the AX5000 to the NC. (Only required if the motor was integrated via an NC axis).

h) The cycle time of the current controller is 125 μs.

i) Selection of the type of ASM connection. If you have generated the motor data set, you can only select the type of connection entered under 3. ‘Basic motor data –a)’. If Beckhoff has generated the motor data set, you can choose between star connection and delta connection.

k) Selection of the ASM control mode. If you select ‘U/f control’, only open-loop operation of the motor is possible; the AX5000 then acts like a frequency converter. If you select ‘i-control with feedback’, closed-loop operation of the motor is possible, but the motor must be equipped with a feedback system. Click on ‘OK’ (1) to complete the procedure.

Open-loop

If open-loop operation of the motor is desired, you can influence the operating behavior with the following parameters.

Interdependence between the type of connection of the motor, the speed, and the rated output current of the AX5000

Example motor:

Asynchronous motor with rated voltage 230 V and rated current 6 A at 50 Hz for delta connection or rated voltage 400 V, rated current 3.5 A at 50 Hz for star connection

If your application requires speeds above the nominal speed (1), this requirement can be realised without having to use a bigger motor:
The AX5000 can provide 400 V of channel output power and thus operate the asynchronous motor in delta connection at up to 87 Hz (2) without field weakening occurring, i.e. with the nominal torque. You only need to note that a rated current of 6 A is required.

Boost voltage

The operation of an asynchronous motor with a linear U/f characteristic curve (see illustration above) results in a weakening of the torque in the lower speed range due to the dominant resistive component. The standstill torque is zero without a boost voltage. Furthermore, the asynchronous motor requires a certain time after the current is applied in order to build up the magnetic field on the rotor and, hence, to generate the magnetic force or the torque. If your application can not tolerate this delay, there is a possibility to reduce this time delay via the so-called ‘boost voltage’, which ‘premagnetises’ the rotor. With ‘premagnetisation’ a magnetic field is created in the rotor even though the rotor is not moving. Torque is hence immediately available to rotate the rotor shaft if a target speed is specified. The interdependence between the boost voltage, speed and torque is illustrated in the graphic below on the basis of an example motor. The influence of the boost voltage on to the torque is clearly visible at low speeds.

Example motor:
Nominal speed: 1410 rpm
Rated torque: 10.2
Breakdown torque: 28.6
Starting torque: 25.5
Power factor: 0.78
Efficiency: 0.79

The boost voltage is parameterised in the IDN-P-0-0103. Most applications will be covered by the default setting of 10 V.

Settings for ramping up and down

In the open-loop operation of the asynchronous motor, the values you need to adjust for the ramps depend on the application.
The ramp-up is parameterised in the IDN S-0-0136 and the ramp-down in the IDN S-0-0137.

Closed-loop

If closed-loop operation of the asynchronous motor is desired, you must select the feedback system used in the motor in the TCDM.

Feedback

Start the TCDM and click the entry (2) under the relevant channel (1) in the tree; the motor/feedback configuration appears in the TCDM working area. Click on the ‘Feedback 1’ (3) field to open the ‘Feedback selection window’. You can view all available feedback systems in the ‘Feedback selection window’.

1a. Feedback selection – resolver

You can only select one existing feedback system. Either choose the feedback system of an existing manufacturer or choose a standard feedback system under ‘Unknown’ (1). If your motor is equipped with a resolver, determine the parameters of the resolver, and select the appropriate resolver type (2). Typical parameters for the classification of resolvers are the number of poles ‘p’ and the gear ratio ‘n’. Click on ‘OK’ (3) to complete the procedure.

1b. Feedback selection - 1Vpp encoder

You can only select one existing feedback system. Either choose the feedback system of an existing manufacturer or choose a standard feedback system under ‘Unknown’ (1). If your motor is equipped with a 1Vpp encoder, determine the parameters of the feedback system and select the appropriate encoder (2). Typical parameters for the classification of 1Vpp encoders are the number of lines ‘s’ and the supply voltage ‘5 V or 5 V fixed’. The difference between the two voltage variants is the use of a sense line (5 V). Click on ‘OK’ (3) to complete the procedure.

1c. Feedback selection - TTL encoder

You can only select one existing feedback system. Either choose the feedback system of an existing manufacturer or choose a standard feedback system under ‘Unknown’ (1). If your motor is equipped with a TTL encoder, determine the parameters of the feedback system and select the appropriate TTL encoder (2). Typical parameters for the classification of TTL encoders are the number of lines ‘s’ and the supply voltage ‘5 V or 5 V fixed’. The difference between the two voltage variants is the use of a sense line (5 V). Click on ‘OK’ (3) to complete the procedure.

Commutation

In asynchronous motors the rotor magnetic field is generated electrically by means of rotor windings, which are energized by the servo drive. For this reason, neither a part-absolute nor an absolute encoder system is required for commutation; wake+shake also does not need to be used.

X13 (A), X23 (B): Motor connection (AX5101 - AX5125 und AX520x)

X14 (A), X24 (B): Motor brake, thermal contact

Output current The specified output currents are maximum values. The actual values depend on your current configuration.

AM2000 with resolver

Via resolver cable.

AM2000 with EnDat

The thermal protection contact is implemented in the encoder cable to the AX5000 and must be bridged to the resolver connection via an adapter / Y cable.

AM2000 with BiSS

Not available.

AM3000 with resolver

Via resolver cable.

AM3000 with EnDat

Via motor cable.

AM3000 with BiSS

Via motor cable.

Linear motors AL2000

The thermal protection contact exits the motor via a separate cable.

1. If the pre-assembled Beckhoff motor and encoder cable is used, an additional thermal protection contact cable (ZK4540-0020-xxx) is required for connecting the thermal protection contact with the AX5000 resolver interface, where temperature evaluation takes place.
2. If the AL2250 connector box is used, the thermal protection contact is automatically bridged to the motor cable.

1. Temperature monitoring via PTC, Klixon or bimetal

Evaluation either on the resolver interface (X12 / X22) or the temperature contact (X14 / X24)

2. Analog temperature evaluation (e.g. KTY)

Evaluation only on the temperature contact (X14 / X24)