Method for the non-destructive testing of a stator winding insulation

Patent metadata

Field	Value
Publication number	US-12523604-B2
Application number	US-202118020931-A
Country	US
Kind code	B2
Filing date	Jul 23, 2021
Priority date	Aug 21, 2020
Publication date	Jan 13, 2026
Grant date	Jan 13, 2026

Abstract

A method and testing device for the non-destructive testing of at least partial regions of an insulation of a stator winding of an electric machine, in particular a generator of a high-voltage motor, wherein the non-destructive testing is carried out in situ at the installation site of the electric machine using terahertz measurement technology.

First claim

The invention claimed is:

1 . A method for a non-destructive testing of at least partial regions of an insulation of a stator winding of an electric machine, comprising:
carrying out the non-destructive testing of the stator winding while the stator winding is fully assembled in situ at an installation site of the electric machine using terahertz measurement technology.

2 . The method as claimed in claim 1 ,
wherein the non-destructive testing is carried out on those partial regions of the insulation which are accessible from outside.

3 . The method as claimed in claim 1 ,
wherein the non-destructive testing is carried out using a terahertz sensor, which is moved along surfaces of partial regions of the insulation that are to be tested and carries out measurements at different measurement positions.

4 . The method as claimed in claim 3 ,
wherein sensor signals emitted by the terahertz sensor are introduced at predetermined angles into the surfaces of partial regions of the insulation that are to be tested.

5 . The method as claimed in claim 4 ,
wherein signals received by the terahertz sensor in response to the emitted sensor signals are stored together with the respective position and orientation of the terahertz sensor at a time at which the sensor signals are emitted, based on a predetermined coordinate system.

6 . The method as claimed in claim 3 ,
wherein the terahertz sensor is used to scan the surfaces of partial regions of the insulation that are to be tested and individual two-dimensional sectional planes or sectional images through the insulation are generated by recording complete depth information relating to the insulation at individual measurement points in each case.

7 . The method as claimed in claim 6 ,
wherein quasi-3D images of the partial regions of the insulation that are to be tested are generated based on generated two-dimensional sectional planes or sectional images.

8 . The method as claimed in claim 3 ,
wherein the terahertz sensor is moved in an automated manner using an electromechanical displacement unit.

9 . The method as claimed in claim 8 ,
wherein the electromechanical displacement unit is arranged on a rotor of the electric machine and is moved on said rotor.

10 . The method as claimed in claim 8 ,
wherein the electromechanical displacement unit is attached to the stator of the electric machine at a first position and detached after a number of measurements have been carried out, and is attached to the stator of the electric machine at a second position, different from the first position, in order to carry out further measurements.

11 . A testing device designed for carrying out a method as claimed in claim 1 , comprising
an electromechanical displacement unit and a terahertz sensor arranged thereon.

12 . The testing device as claimed in claim 11 ,
wherein the electromechanical displacement unit is a buckling arm robot.

13 . The testing device as claimed in claim 11 ,
wherein the electromechanical displacement unit is designed to be arranged on a stator of an electric machine, and to be moved on said stator in a motor-driven manner.

14 . The testing device as claimed in claim 11 ,
wherein the electromechanical displacement unit is designed to be attached to a stator of an electric machine, at a first position and detached after a number of measurements have been carried out, and to be attached to the stator of the electric machine at a second position, different from the first position, in order to carry out further measurements.

15 . The testing device as claimed in claim 11 ,
wherein the terahertz sensor has at least one dielectric measurement tip, wherein the at least one dielectric measurement tip comprises a 90-degree bend at its free end, and wherein the free end is configured to fit between adjacent bars of the stator winding.

16 . The testing device as claimed in claim 11 ,
wherein the terahertz sensor has a quasi-optical free-beam system designed to direct terahertz radiation onto a measurement position.

17 . The method as claimed in claim 1 ,
wherein the electric machine comprises a generator or a high-voltage motor.

18 . The method as claimed in claim 2 ,
wherein the partial regions of the insulation comprise those which surround involutely curved sections of the stator winding that protrude outwardly from grooves in the stator.

19 . The method as claimed in claim 4 ,
wherein the predetermined angles are 90°.

20 . The method as claimed in claim 6 ,
wherein the depth information in the terahertz measurement is obtained by way of frequency-modulated continuous wave radar method.

21 . The method as claimed in claim 8 ,
wherein the electromechanical displacement unit comprises a buckling arm robot holding the terahertz sensor.

22 . The testing device as claimed in claim 13 ,
wherein the electric machine comprises a generator or a high-voltage motor.

23 . The testing device as claimed in claim 14 ,
wherein the electric machine comprises a generator or a high-voltage motor.

Assignees

• Siemens Energy Global Gmbh & Co Kg
• Fraunhofer Ges Forschung

Inventors

• Bauer Maris
• Friederich Fabian
• Hansmann Daniel
• Jonuscheit Joachim
• Krane Stefan
• Mashkin Andrey
• Pohlmann Friedhelm
• Rohr Claus

Classifications

• G01N21/9515 Primary

  Objects of complex shape, e.g. examined with use of a surface follower device (measuring contours and curvatures G01B11/24) · CPC title

• G01N2021/9518

  using a surface follower, e.g. robot · CPC title

• Y02E10/72

  Wind turbines with rotation axis in wind direction · CPC title

• G01N21/3581 Primary

  using far infrared light; using Terahertz radiation · CPC title