SU1597801A1 - Method of testing the winding wires - Google Patents

Abstract

The invention relates to instrumentation engineering and can be used to test winding wires under actual operating conditions. The purpose of the invention — to increase the reliability of testing — is achieved by creating conditions close to the conditions of operation. A sample made in the form of a pair of conductors twisted with no more than one twist with a step equal to the active length of the sample is simultaneously affected by a mechanical tensile force, an electric gas discharge fixed by the test voltage. In addition, the sample is subjected to mechanical stretching, as well as to heating and the effects of electrodynamic forces, which is achieved by current flowing through the sample wires in phase. The test voltage on the sample is supplied as a superposition of a sinusoidal voltage with an amplitude below the ionization threshold and a pulse switching voltage. The time from the moment of application of the loads to the breakdown of the insulation of the sample, the moment of which is recorded, is then measured. The invention improves the reliability of testing winding wires and allows their reliability characteristics to be determined, without resorting to the manufacture of the windings themselves or their layouts. 1 il.

Description

The invention relates to measurement instrumentation and can be used in testing winding wires under specified operating conditions.

The purpose of the invention is to increase the reliability of the test by creating test conditions close to the conditions of the exploitation.

The method consists in that a sample made in the form of a pair of conductors with no more than one twist with a step equal to the active length of the sample is simultaneously affected by an electric gas discharge fixed by the test voltage and the time to breakdown is measured. In addition, the sample is subjected to mechanical stretching, heating by current, and the action of electrodynamic forces. The heating and excitation of electrodynamic forces are produced by the current flowing through the wires shaped like synphia. The sample is supplied with a test voltage in the form of a superposition of sinusoidal voltage with an amplitude below the ionization threshold and a switching pulse, and is also affected by a mechanical tensile force.

In the drawing, a diagram of the device that realizes the method is shown.

Sample 1 in a single twisted pair of segments of the test wire, is fastened with the ends released from the insulation in the mechanical stretching device 2. Each wire () BRYa-M1a 1 is connected to sources 3 and 4 of the current. and also to the SOURCE 5 ispg, tat (, chno-1 ate

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prine The sample is placed near the electrode 6, to which a source of ionizing voltage 7 is connected with respect to one of the wires of sample 1. 8 sample indicator is also connected to sample 1 wires.

The method of testing winding wires is carried out as follows.

The mechanical stretch device 2 creates a tensile sample 1 load, for example, equal to the tension of the wire during the manufacture of the winding. The required heating of the wires is established by adjusting the current from sources 3 and 4. The heating temperature is controlled by any known method, for example, by the method of optical pyrometry. From test voltage source 5, sample 1 is supplied with a test voltage in the form of a superposition of a sinusoidal voltage of industrial frequency and a switching voltage acting between adjacent winding turns. The voltage on the electrode 6 is set by adjusting the source 7 such that, under actual operating conditions, the windings cause ionization of the gas space around sample 1 and partial discharges, for example, corresponding to switching overvoltage at the ends of the winding. All external loads (external actions) after preliminary adjustment are simultaneously applied to the sample and the time from the moment of application of the load to the sample insulation is measured, the sample time being fixed by indicator 8. The adequacy of the proposed method to failure of inter-turn insulation under operating conditions is determined by the conditions and its mechanism of testing. - The isolation of a pair of wires of sample 1, brought into close contact, is acted upon by a test voltage in the form of a superposition of a sinusoidal voltage of industrial frequency and a switching voltage, the magnitude of which is equal to the corresponding voltages between the adjacent windings of the real winding. Isolation of wires is subjected to the activating effect of direct current heating, mechanics;

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Compiled by E. Berezov

Tehred A. KravchukKorrektor L. Patay

Circulation 561 Subscription

VNIIPI Gosulshkh-tiennogo committee on inventions and discoveries miri 1 K.I 1 (ALL

 113035. Moscow, Zh-35, Raushsk nab., 4 / o Proizvodstvinoino.pudatelskiy combine "Patent, Uzhgorod, st. Gagarin. 1 (11

Editor. Patruigeva Order .3052

0

s 25 30 35,

and electrodynamic forces, gas discharge plasma. Isolation breakdown occurs in the following sequence. at the moment of the application of external effects on the sample between the electrode 6 and one of the wires of the sample 1, an electric gas discharge occurs along its entire active length. After some time, the discharge is localized between two points: on the external electrode b and the corresponding sample wire. Then breakdown of the insulation occurs between the sample wires in the place developed by the gas discharge of the insulation defect. For a given external test, the time from the start of the test to the breakdown determines the actual life of the test wire under simulated operating conditions.

The invention improves the reliability of testing winding wires and makes it possible to determine the reliability characteristics without having made the manufacture of the windings themselves or their layouts.

Claims (1)

Invention Formula The method of testing winding wires, which consists in the fact that a sample made in the form of a twisted pair of wires is subjected to an electric gas discharge, while applying a test voltage between the specified wires and measuring the time until the insulation of the specified wires is broken, topics that, in order to increase the reliability of the test, a mechanical twist force is applied to an o6j sample made with no more than one twist with a step equal to the active length of the sample, an in-phase current is passed through the sample wires, the test voltage is applied to superposition of a sinusoidal voltage of industrial frequency and a switching voltage, and the impact on the sample of an electric gas discharge is provided by applying an appropriate test voltage between one of the sample wire and external electrode.