SU1553929A1 - Method of detecting turn-to-turn short circuits in electric coils - Google Patents

Abstract

This invention relates to instrumentation technology. The purpose of the invention is to increase the sensitivity by detecting a small number of short-circuited coils-achieved by additionally measuring the EMF E of the coil during coupling of a sinusoidally changing magnetic flux, measuring its resistance R to direct current and finding the number of short-circuited coils W _to according to the formula: W _to = F _to ^. R / E, where F _to - the measured value of the magnetomotive force of the coil. 1 il.

Description

This invention relates to instrumentation technology.

The purpose of the invention is to increase the sensitivity by detecting a small number of short-circuited turns.

The drawing shows a diagram of the device that implements the method.

The device contains a source of 1 sinusoidally varying magnetic flux, a source of 2 direct current and a complex of 3 measuring devices, functionally connected with the diagnosed coil 4 and sources 1 and 2. A reference coil with a known number of turns wo can be used as a source of sinusoidal magnetic flux , connected under a sinusoidal voltage, for example, a generator of signals of the type GSS and located on the same magnet duct as the diagnosed coil 4. The bottom is to monitor and maintain constant The amplitude of the magnetic flux can be used special measuring coil. By maintaining a constant voltage Uc at the terminals of this coil, it is possible to ensure the amplitude stability by a sinusoidally varying magnetic flux. In order to exclude the roughing effect of the reactive component of the current consumed by the reference coil during the measurement of the magnetomotive force, parallel to the latter it is advisable to turn on the variable capacitor tuned to the resonance with the reactive conductivity of the reference coil.

Determining the number of short-closed turns w., In the diagnosed

(

The coil is implemented as follows.

Diagnosed coil 4 is placed on a common with the reference coil, the source 1 of a sinusoidal magnetic flux, the magnetic core. Measure (I

with

ate

with

WITH

to

with

The magnetomotive force of the coil is calculated as the product of the number of turns of the supporting coil and the difference of the active component currents 410 consumed by this coil from the source of electrical energy and corresponding to the cases when the diagnosed Katutac is not placed near the reference one:

I kw

w0- / ii0,

Further, under the same conditions, the electromotive force E w E is measured at the terminals of the monitored coil, and after connecting it under the voltage of the source DC current, the active resistance is measured

R U / I R6 w,

as the ratio of the voltage source U to the current created by it I

Then, the number of short-circuited turns is determined by the formula:

wk FKR / E.

Indeed, R B R / w, E0 therefore the ratio E / R E6w / Rftw from here

FKR / E Fk / IK - WK,

five

0

five

where R is the DC resistance of the coil; R. - resistance of one turn

coils; Ev-electromotive force of one

coil turn;

w is the total number of turns of the coil.

Claims (1)

Invention Formula The method of detecting the short circuits of electric coils, according to which the magnetomotive force of the controlled coil is measured, characterized in that, in order to increase the sensitivity, a sinusoidally varying magnetic flux is used, the electromotive force of the coil and its resistance to direct current are also measured, and the number short-circuited turns are judged by the product of the magnetomotive force of the coil by its resistance to direct current to the electromotive force of the coil.