SU1597651A1 - Method of vibration testing of electric motor stator winding - Google Patents

Abstract

This invention relates to a vibration test technique for electrical machines. The purpose of the invention is to increase test performance. During the tests, oscillations of the frontal parts of the electric machine winding are excited by electrodynamic forces, which are created by passing an industrial frequency alternating current through the winding. In this case, the winding is heated to a temperature at which the lower natural frequency of the frontal parts is equal to the excitation frequency. The maintenance during testing of the temperature at which the resonant mode of oscillation of the frontal parts is ensured leads to an increase in the test performance. 2 Il.

Description

The invention relates to a testing technique, in particular to vibration tests of windings of electrical machines.

The purpose of the invention is to improve the performance of tests

Fig 1 shows the scheme of the tests according to the proposed method; FIG. 2 shows a graph of the dependence of the resonant frequency of the winding frontal parts on its temperatureJ

During vibration tests, the windings of an electric machine excite oscillations of the frontal winding parts by electrodynamic forces, which are created by passing an alternating current through the industrial winding from the industrial network. At the same time, they provide a resonant mode by varying the rigidity of the frontal parts by heating the winding to a temperature at which the natural frequency parts equal to the frequency of excitation.

PRI m e RO Conducted testing of an asynchronous motor with a power of 11 kW at 3000 rpm, having a single-layer concentric stator winding and a short-circuited rotor. Thermocouples 2 were laid in the frontal parts of the motor windings to measure the temperature recorded with a potentiometer 1 {3. Connect the motor windings to the mains: - of the current, the oscillations of the frontal parts were excited 1 The vibration control was performed using vibration sensors 4 and a spectrum analyzer 5

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Brksh and. At the same time, the engine was heated by increasing the stator current of the Tphi with a single phase break. At different temperatures of the frontal parts, we determined the values of their natural frequency f. The coincidence of the first natural frequency with the frequency of electrodynamic forces equal to twice the frequency of the industrial current was recorded at a temperature of 116 ° C. At the same time, the total vibration level increased to 85 dB (temperature 42 C corresponded to the vibration level 45. dB).

Maintaining, when testing, the temperature of the winding at which a resonant mode of oscillation is provided

Claims (1)

parts, causes an increase in productivity tests The method of vibration testing of the stator winding of an electric machine, by which oscillations of the frontal parts of the electric machine winding are induced by electrodynamic forces that create an industrial frequency by passing an alternating current winding, characterized in that, in order to increase the test performance, the winding is heated to a temperature at which the lowest proper the frequency of the frontal parts is equal to the frequency of excitation, and when tested, test this temperature 400 200 FIG. one Editor Eopapp . Compiled by D, Danilov Tehred-L. Oliynyk Proofreader With Cherni Order 3045. Circulation 440 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, .ZH-35, Raushsk nab. 4/5 5U FIG. 2 100 i.c Subscription