Method and device for the computer-assisted operation of an electric motor

Patent metadata

Field	Value
Publication number	US-10873286-B2
Application number	US-201716469022-A
Country	US
Kind code	B2
Filing date	Dec 6, 2017
Priority date	Dec 16, 2016
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

Provided is a method for the computer-assisted operation of an electric motor which is exposed to a thermal load as a result of the rotational motion of its rotor during operation. In this method, measured data is received during the operation of the electric motor. One or more temperature values are derived from the measured data. A number of temperature characteristics curves are then forecast with differing restart times for defining a cooling period for reducing the thermal load on the electric motor, wherein the approximated temperature value, which results from the approximated temperature value is used as the specific starting value for a restart in the temperature characteristics curve to be forecast.

First claim

The invention claimed is:

1. A method for the computer-assisted operation of an electric motor which is subjected, during an operation of the electric motor, to a thermal loading by a rotational motion of a rotor of the electric motor, the method comprising:
receiving measurement data measured during the operation of the electric motor, wherein the measurement data are electrical and/or kinetic physical variables of the electric motor;
determining at least one temperature value, approximated to a virtual real value, by means of a mathematical module, derived from a predefineable motor geometry, for physical variables of an overall state of the motor, and from the received measurement data as input data;
predicting a number of temperature profiles with different restart times, wherein the temperature profiles are each dependent on the overall state of the electric motor and/or on a configuration of the electric motor, in order to define a cooling time period for reducing the thermal loading on the electric motor, wherein the approximated temperature value, which results from the at least one virtual real value, is input as a respective starting value for a restart into the temperature profile which is to be predicted;
displaying a temperature profile which lies in the past, together with the number of predicted temperature profiles in a time/temperature diagram, wherein the number of predicted temperature profiles represents a possible restart of the electric motor at the respective restart time with the respectively determined starting value;
determining a respective quality measure for the number of predicted temperature profiles, wherein the quality measure is a measure of the efficiency of how good the restart time is with respect to the expected thermal loading and a minimum of the cooling time period; and
mapping the quality measures onto a color scale which is visually output at a user interface, wherein time information relating to the restart of the electric motor is output in response to a user interaction which is input via the user interface.

2. The method as claimed in claim 1 , wherein an expected temperature profile, a first temperature profile with an upper confidence limit and a second temperature profile with a lower confidence limit are determined for each predicted temperature profile.

3. The method as claimed in claim 2 , wherein, in the display of the predicted temperature profiles, the respective expected temperature profiles are displayed as long as no user interaction is or has been determined.

4. The method as claimed in claim 2 , wherein, when an interaction which comprises a selection of one of the predicted temperature profiles is detected, the expected temperature profile thereof, the first temperature profile thereof and the second temperature profile thereof are displayed in the display.

5. The method as claimed in claim 1 , wherein an upper temperature threshold, which represents a hardware limit of the electric motor, and a lower temperature threshold, which is a limit for an efficient operation of the electric motor are defined, wherein the respective quality measures for the number of predicted temperature profiles are determined as a function of the defined upper and lower temperature thresholds.

6. The method as claimed in claim 5 , wherein the upper and lower temperature thresholds are displayed in the display and can be changed in their absolute value by a user interaction.

7. The method as claimed in claim 1 , wherein the number of predicted temperature profiles is defined by a user interaction.

8. The method as claimed in claim 2 , wherein a prediction range for the temperature is determined for a respective predicted temperature profile in that the difference of a respective temperature maximum is determined for the first and second temperature profiles, which temperature maximum is reached when the assumed switching-off of the electric motor occurs.

9. The method as claimed in claim 8 , wherein the prediction range projects into one or more of the following ranges or lies in said ranges:
an upper range, which lies above the upper temperature threshold,
a middle range, which lies between the upper and the lower temperature thresholds,
a lower range, which lies below the lower temperature threshold, wherein the quality measure is determined from the respective portions of the overlapping of the prediction range with the upper range and/or the middle range and/or lower range.

10. The method as claimed in claim 9 , wherein the upper, middle and lower ranges are each assigned a color of a predefined color space, further wherein the respective colors are predefined, pure, colors of a central angle of the predefined color space.

11. The method as claimed in claim 10 , wherein the quality measure is a mixed color of the central angle of the predefined color space.

12. The method as claimed in claim 9 , wherein in the color scale the region between two adjacent quality measures is a color gradient which results from the colors of a shortest connection of the mixed colors of the quality measure which lie on the color angle of the predefined color space.

13. The method as claimed in claim 9 , wherein the time information relating to the restart of the electric motor is determined on the basis of the color saturation of the color of the middle range.

14. A computer program, comprising a computer readable hardware storage device having computer readable program code stored therein, said program code executable by a processor of a computer system to implement a method comprising:
receiving measurement data measured during the operation of the electric motor, wherein the measurement data are electrical and/or kinetic physical variables of the electric motor;
determining at least one temperature value, approximated to a virtual real value, by means of a mathematical module, derived from a predefineable motor geometry, for physical variables of an overall state of the motor, and from the received measurement data as input data;
predicting a number of temperature profiles with different restart times, wherein the temperature profiles are each dependent on the overall state of the electric motor and/or on a configuration of the electric motor, in order to define a cooling time period for reducing the thermal loading on the electric motor, wherein the approximated temperature value, which results from the at least one virtual real value, is input as a respective starting value for a restart into the temperature profile which is to be predicted;
displaying a temperature profile which lies in the past, together with the number of predicted temperature profiles in a time/temperature diagram, wherein the number of predicted temperature profiles represents a possible restart of the electric motor at the respective restart time with the respectively determined starting value;
determining a respective quality measure for the number of predicted temperature profiles, wherein the quality measure is a measure of the efficiency of how good the restart time is with respect to the expected thermal loading and a minimum of the cooling time period; and
mapping the quality measures onto a color scale which is visually output at a user interface, wherein time information relating to the restart of the electric motor is output in response to a user interaction which is input via the user interface.

15. A device for the computer-assisted operation of an electric motor which is subjected, during an operation of the electric motor, to a thermal loading by a rotational motion of a rotor of the electric motor, the d

Assignees

• Siemens Ag

Inventors

• Mittelstädt Sebastian
• Mlynek Jonas
• Weber Stefan Hagen

Classifications

• H02P1/029

  Restarting, e.g. after power failure · CPC title

• H02P29/60

  Controlling or determining the temperature of the motor or of the drive (H02P29/02 takes precedence) · CPC title

• H02P23/14

  Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage · CPC title

• H02P1/26

  for starting an individual polyphase induction motor · CPC title

• H02P1/16 Primary

  for starting dynamo-electric motors or dynamo-electric converters · CPC title