SU1164633A1 - Transducer for detecting short-circuit turns in stator windings of electric machines - Google Patents

Abstract

SENSOR FOR DETECTING SHORT-CLOSE ROLLS IN THE WINDINGS OF ELECTRIC MACHINE STATORS, containing located in two planes, perpendicular to the axis of the sensor. electromagnets with magnetic conductors and windings, the first terminals of which are connected to the corresponding sensor terminals, characterized in that, in order to expand technological capabilities and increase productivity, a magnetic screen is inserted into it, which is located between the electromagnets in the plane perpendicular to the sensor axis, and the mag ; the nitropower is made in the form of a multipole rotor with the number of poles equal to the number of poles of the tested stator, and at each pole there are: one winding, the second terminals of which are connected between themselves. (L

Description

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This invention relates to electrical engineering, in particular to test measuring devices.

A device for controlling packages of magnetic circuits of multi-pole electric machines is known, made in the form of a symmetric myogolar magnetic circuit whose poles contain magnetizing and measuring windings Cl J.

However, this device does not allow short-circuited turns to be detected in the stator windings.

A device is known for detecting short-circuited coils in the stators of electric machines, comprising a system of two electromagnets with U-shaped magnetic cores, which are located above a single groove in the stator of the electric machine L2.

This device allows to locate the defective winding with short-circuited coils, however, to check all the windings, it is necessary to rotate the stator with respect to the sensor.

Also known induction sensor for controlling short-circuited coils, containing inside

the stator is a system of electromagnets, the magnetic circuits of which are made in the form of rods and mounted along the stator diameter in planes of different height, and the number of electromagnets is chosen equal to the number of pairs of pole stator coils Z.

Such an embodiment of the sensor for monitoring short-circuited coils allows testing multi-pole stators by switching the corresponding sensor coils, i.e., without rotating the sensor with respect to the stator.

However, such a sensor is not possible for stators with an odd number of poles. In addition, the placement of rods in planes of different height of the sensor leads to an increase in the size of the sensor in height; as these sizes decrease, direct inductive coupling between electromagnets increases. This prevents the manufacture of sensors for testing small multipole stators with a small package thickness.

The aim of the invention is to expand the technological capabilities of the sensor and increase productivity, namely the provision of an automated check of the expanded nomenclature of the stators of micromotors.

The goal is achieved by the fact that electromagnets with magnetic conductors and windings, the first terminals of which are connected to the corresponding terminals of the sensor, are inserted into a sensor containing two electrodes in the two planes perpendicular to the sensor axis, which is located between the electromagnets in the plane of the sensor perpendicular axis, and the magnetic circuit is made in the form of a multi-pole rotor with the number of poles equal to the number of poles of the tested stator, with one winding placed at each pole, the second terminals of which interconnected.

FIG. 1 shows schematically the proposed sensor; in fig. 2 - drawings explaining his work.

The sensor contains a system of two electromagnets, placed inside the tested stator 1, made in the form of multi-pole rotors 2 and 3 installed along the diameter of the tested stator 1 along the edges of its package.

 The number of poles of rotors 2 and 3 is equal to the number of poles of the tested stator 1 and one winding 4 is located at each pole of rotor 2 and 3. The windings 4 of each rotor 2 and 3 are soldered to the sensor terminals 5 and can be connected, for example, with a star by zero. To eliminate the direct connection between the electromagnets there is a magnetic screen 6..

The assembled sensor is poured with epoxy compound, and its working diameter is adjusted to a value that provides a running fit for the stator 1 on the sensor.

The terminals of the windings of the rotors 2 and 3 for-. A switch (not shown) is alternately connected to alternating voltage generator 7 and to indicator 8..

The sensor operates as follows. The tested stator 1 is mounted on the sensor in such a way that its loops are located opposite the pole of the sensor rotors, after which the switch is started.

When alternating voltage is applied from generator 7 to the winding of pole 9 of exciting rotor 2, magnetic flux is excited in its magnetic core and adjacent part of stator 1, part of which passes in a plane perpendicular to the stator axis and closes through adjacent poles of the sensor and stator, and the other part of the flow passes along the axis of the stator and closes through the magnetic screen 6. In FIG. Figure 2 shows the magnetic flux passing in a plane perpendicular to the axis of the stator without taking into account the reaction of short-circuited turns to the exciting electromagnet. When there are short-circuited turns in the winding of the stator pole 10, some current is induced in them, creating a magnetic flux along the entire length of the stator pole 10. A part of this flux, closed through the magnetic core 3 of the indicator electromagnet, induces some electromotive voltage E in the winding of the sensor pole 11, and the electromotive force of E / 2 in the windings of the adjacent poles 12 and 13, since the magnetic flux of these poles is two times smaller. When applying the alternating voltage E from the generator 7 to the winding of the pole 14 of the exciting rotor 2 magnetic

t the flux at the stator pole 1Q doubles (Fig. 26), the current e doubles in short-circuited coils, (к.э.в),. Therefore, the emf in IJ of the indicator rotor 3 will be 2E, and on cages 12 and 13 - E. Thus, the input of the indicator 8 at the first step of the switch is supplied with a voltage E / 2, and at the second step. switch, i.e. in the presence of a short-circuit, the voltage at the indicator input will melt 4 times. In the absence of a kzv There is almost no connection between the sensor electromagnets. The magnetic screen mounted along the sensor diameter, eliminating the direct connection between the electromagnets, allows them to be scaled at a small distance from each other, and the electromagnets made in the form of multi-pole rotors have a small thickness. All this provides the possibility of automated control of a wide nomenclature of stators, micromotors, in particular stators with a small thickness of a packet, with a fourth and an odd number of poles.

Claims (1)

SENSOR FOR DETECTING SHORT-CLOSED CIRCUITS IN THE WINDING OF STATORS OF ELECTRIC MACHINES, comprising electromagnets with magnetic conductors and windings located in two planes perpendicular to the axis of the sensor, the first leads of which are connected to the corresponding sensor terminals, characterized in that, in order to increase technological capabilities and to enhance technological capabilities and a magnetic screen is inserted into it, which is located between the electromagnets in a plane perpendicular to the axis of the sensor, and the magnetic circuit is made in the form of multi- lumbar rotor with the number of poles equal to the number of poles of the tested stator, and at each pole there is one winding, the second conclusions of which are interconnected. $ and. „1164633> 1164633 2