Unlock instant, AI-driven research and patent intelligence for your innovation.

Method for detection of interlaminar sheet short circuits in the stator sheet core of electromachines

A technology of stator laminations and gaps, applied in the direction of motor generator testing, etc., can solve problems such as additional costs

Active Publication Date: 2010-12-29
GENERAL ELECTRIC TECH GMBH
View PDF7 Cites 6 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage of this measuring method is that additional expenditure is required for the high-frequency generator for the excitation current
Furthermore, it is disadvantageous that it is necessary to work with precisely set and known or measured values ​​of the stator inductions, since the measured results are compared with absolute limit values ​​and then evaluated

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for detection of interlaminar sheet short circuits in the stator sheet core of electromachines
  • Method for detection of interlaminar sheet short circuits in the stator sheet core of electromachines
  • Method for detection of interlaminar sheet short circuits in the stator sheet core of electromachines

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0039] As already explained at the outset, and like the conventional ELCID method, the novel method operates with a low inductive excitation and a measuring coil for measuring the leakage magnetic field. However, it is particularly distinguished in that the stator is magnetized with a non-sinusoidal (or phase-shifted cosine-shaped) excitation voltage signal profile.

[0040] Typically, especially according to the invention, for example rectangular, trapezoidal, sawtooth-shaped or generally pulse-shaped excitation voltages are used. The period P of the excitation voltage can correspond to the period of the mains voltage, or can also be different therefrom, for example smaller. It is also possible to use aperiodic voltage forms, such as monopulses, for excitation.

[0041] Here generally the rectangular excitation voltage V (see also Figure 5 a) understood as a change curve, for the change curve:

[0042] V(t)=+x, 0≤t

[0043] V(t)=-x, p / 2≤t

[0044] Apply a trapez...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A method and a device are described for the detection of interlaminar sheet short circuits in the stator sheet core of electromachines, wherein the stator sheet core (4) is subjected to an excitation current (2) or excitation voltage (V) applied from the outside and the short circuit magnetic field (B short) induced by short circuit currents (5) is measured with the aid of a sensor coil (S1) arranged in the gap of the machine and sensing said gap. Improved recognition of sheet short circuits, in particular also of small sheet short circuits with low short circuit currents, is possible in that an excitation current (2) or an excitation voltage (V) is applied, which has a chronological sequence deviating substantially from a sinusoidal shape with particularly periodic character and substantially harmonic fractions in the high frequency range. A chronological sequence in the form of a rectangular curve is proposed by way of example.

Description

technical field [0001] The invention relates to a method for detecting laminar short circuits in a stator lamination stack of an electric machine, in particular a large generator. It relates in particular to the development of devices and methods in which the stator lamination stack is subjected to an excitation current or an excitation voltage applied from the outside and the induced short-circuit current is detected by means of a sensor coil which is arranged in the machine gap and detects this gap. short-circuit magnetic field. Background technique [0002] Large generators and electric motors are usually checked for short circuits at rest. There are different methods available for this. [0003] One of these methods consists in magnetizing the entire lamination at grid frequency by means of an auxiliary coil and measuring the leakage magnetic field on the inner surface of the stator bore. This magnetization occurs at a relatively low magnetic induction value, typicall...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G01R31/34
CPCG01R31/34
Inventor M·霍贝尔斯贝格尔
Owner GENERAL ELECTRIC TECH GMBH