MOTOR DRIVE ADAPTATION

• US 20200136544A1
• Filed: 07/27/2017
• Published: 04/30/2020
• Est. Priority Date: 07/27/2017
• Status: Active Grant

• Current Assignee: Danfoss Drives OY
• Original Assignee: Vacon Oy (Danfoss A/S)
• Inventors: Hakli, Simo Hakli, Sodo, Nicklas
• Granted Patent: US 12,034,388 B2
• Time in Patent Office: Days
• CPC Class Codes: G01H 13/00 Measuring resonant frequency
• CPC Class Codes: G05B 13/02 electric
• CPC Class Codes: H02M 1/126 using passive filters
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H02P 23/00 Arrangements or methods for the control of AC motors characterised by a control method other than vector control
• CPC Class Codes: H02P 23/0004 Control strategies in general, e.g. linear type, e.g. P, PI, PID, using robust control
• CPC Class Codes: H02P 23/14 Estimation or adaptation of motor parameters, e.g. rotor time constant, flux, speed, current or voltage
• CPC Class Codes: H02P 27/06 using dc to ac converters or inverters H02P27/05 takes precedence

Abstract

A method and apparatus for the adaptation of a motor drive system is described. The method includes applying a small signal frequency sweep to a motor drive system wherein the motor drive system includes an inverter, an output filter (e.g. a sine filter) and a motor, acquiring frequency response data in response to said frequency sweep and setting parameters of the motor drive system depending on the acquired frequency response data.

Claims

1. A method comprising:

applying a small signal frequency sweep to a motor drive system wherein the motor drive system includes an inverter, an output filter and a motor;

acquiring frequency response data in response to said frequency sweep in order to determine resonances in the motor drive system; and

setting parameters of the motor drive system depending on the acquired frequency response data.

2. The method as claimed in claim 1, wherein applying a small signal frequency sweep comprises applying a low voltage magnitude signal to the motor over a frequency range.

3. The method as claimed in claim 1, wherein said acquired frequency response data comprises current data as a function of frequency resulting from the applied frequency sweep.

4. The method as claimed in claim 1, wherein:

applying the small signal frequency sweep comprises applying multiple small signal frequency sweeps at different DC offset levels; and

acquiring frequency response data comprises acquiring frequency response data for each of said multiple small signal frequency sweeps.

5. The method as claimed in claim 1, further comprising:

applying a DC magnetising pulse and repeating said frequency sweep applying and frequency response data acquiring steps.

6. The method as claimed in claim 1, further comprising repeating said frequency sweep applying and frequency response data acquiring steps periodically.

7. The method as claimed in claim 6, further comprising determining whether a change in said frequency response data is indicative of a significant performance change.

8. The method as claimed in claim 1, wherein said parameters include one or more of a minimum, an optimum and a maximum switching frequency of said inverter.

9. The method as claimed in claim 1, wherein said output filter is a sine filter.

16. The method as claimed in claim 2, wherein said acquired frequency response data comprises current data as a function of frequency resulting from the applied frequency sweep.

17. The method as claimed in claim 2, wherein:

applying the small signal frequency sweep comprises applying multiple small signal frequency sweeps at different DC offset levels; and

acquiring frequency response data comprises acquiring frequency response data for each of said multiple small signal frequency sweeps.

18. The method as claimed in claim 3, wherein:

applying the small signal frequency sweep comprises applying multiple small signal frequency sweeps at different DC offset levels; and

acquiring frequency response data comprises acquiring frequency response data for each of said multiple small signal frequency sweeps.

19. The method as claimed in claim 2, further comprising:

applying a DC magnetising pulse and repeating said frequency sweep applying and frequency response data acquiring steps.

20. The method as claimed in claim 3, further comprising:

applying a DC magnetising pulse and repeating said frequency sweep applying and frequency response data acquiring steps.

10. A motor drive system comprising an inverter stage, a control module and an output filter, wherein the control module is configured to set parameters of the motor drive system depending on a measured frequency performance of the motor drive system, wherein the frequency performance is measured in response to applying a small signal frequency sweep to the motor drive system.

11. The motor drive system as claimed in claim 10, wherein the small signal frequency sweep is applied under the control of said control module.

12. The motor drive system as claimed in claim 10, further comprising a cable connecting an output of the inverter stage to a motor.

13. The motor drive system as claimed in claim 10, wherein said parameters include one or more of a minimum, an optimum and a maximum switching frequency of said inverter stage.

14. The motor drive system as claimed in claim 10, wherein said output filter is a sine filter.

15. A computer program product comprising:

means for applying a small signal frequency sweep to a motor drive system;

means for acquiring frequency response data in response to said frequency sweep in order to determine resonances in the motor drive system; and

means for setting parameters of the motor drive system depending on the acquired frequency response data.