METHOD FOR MEASURING A STATOR CORE OF AN ELECTRIC MACHINE AND MEASURING DEVICE

• US 20160370324A1
• Filed: 06/13/2016
• Published: 12/22/2016
• Est. Priority Date: 06/19/2015
• Status: Active Grant

• Current Assignee: General Electric Technology GmbH (GE Vernova, Inc.)
• Original Assignee: Alstom Technology Ltd. (Alstom SA)
• Inventors: HOBELSBERGER, Maximilian
• Granted Patent: US 10,458,949 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 27/82 for investigating the presence of flaws
• CPC Class Codes: G01R 31/34 Testing dynamo-electric machines
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: H02K 11/25 Devices for sensing temperature, or actuated thereby

Abstract

A method for measuring a stator core of an electrical machine includes the steps of winding at least one excitation coil around the stator core, applying a discontinuous voltage to the excitation coil(s) to magnetically excite the stator core, and measuring a quantity of the magnetically excited stator core. Further, a corresponding measuring device is disclosed.

Claims

1. A method for measuring a stator core of an electrical machine comprising:

winding at least one excitation coil around the stator core;

applying a discontinuous voltage to the at least one excitation coil to magnetically excite the stator core; and

measuring a quantity of the magnetically excited stator core.

2. The method according to claim 1, wherein the waveform of the excitation voltage is rectangular, burst, triangular, or sinusoidal.

3. The method according to claim 2, wherein the excitation voltage has pulses of a time duration between 2 ms and 5 ms with a rate between 50 pulses and 100 pulses per second.

4. The method according to claim 3, wherein an excitation device creating the discontinuous excitation voltage provides the voltage with a frequency of 50 Hz or 60 Hz.

5. The method according to claim 4, wherein the excitation device provides the discontinuous excitation voltage to generate a magnetic flux density B of the stator core of approximately 1.5 Tesla.

6. The method according to claim 5, wherein the excitation device comprises at least a capacitor to provide the discontinuous excitation voltage by discharging.

7. The method according to claim 6, wherein the at least a capacitor is fed by two power supplies coupled together.

8. The method according to claim 7, wherein measuring the quantity of the magnetically excited stator core is carried out by a detecting device, the detecting device comprising an acoustic device which measures the vibrations of the stator core caused by the magnetic excitation, and wherein the detecting device or a calculation unit is configured to determine a stability of the stator core on basis of the measurements.

9. The method according to claim 8, wherein the acoustic device comprises at least a microphone.

10. The method according to claim 7, wherein measuring the quantity of the magnetically excited stator core is carried out by a detecting device, the detecting device comprising an optical device which measures temperature differences at the stator core caused by the magnetic excitation, and wherein the detecting device or a calculation unit is configured to determine interlaminar laminate shorts on basis of the measurements.

11. The method according to claim 10, wherein the excitation voltage has pulses of a time duration between 5 ms and 20 ms.

12. The method according to claim 10, wherein the excitation voltage has pulses of a time duration between 2 ms and 10 ms.

13. A measuring device for measuring a laminated stator core of an electrical machine comprising:

an excitation device for magnetically exciting the stator core which comprises at least an excitation coil wound around the stator core,

wherein the excitation device is configured to generate a discontinuous voltage applicable to the excitation coil to magnetically excite the stator core;

at least one detection device configured to measure a quantity of the magnetically excited stator core; and

a calculation unit configured to determine properties of the stator core on basis of the measurements of the at least one detection device.

14. The measuring device according to claim 13, wherein the at least one detection device comprises an acoustic device which measures the vibrations of the stator core caused by the magnetic excitation and the calculation unit determines the stability of the stator core.

15. The measuring device according to claim 13, wherein the at least one detection device comprises an optical device which measures temperature differences at the stator core caused by the magnetic excitation and the calculation unit determines laminated shorts of the stator core.

16. The measuring device according to claim 13, wherein the at least one detection device comprises a first detection device and a second detection device, the first detection device comprises an acoustic device which measures the vibrations of the stator core caused by the magnetic excitation and the calculation unit determines the stability of the stator core, and the second detection device comprises an optical device which measures temperature differences at the stator core caused by the magnetic excitation and the calculation unit determines laminated shorts of the stator core.