SU1332467A1 - Method of diagnostics of compaction condition of a laminated core of an electric machine - Google Patents

Abstract

The invention relates to electrical engineering and can be used in turbo and hydrogenerators. The aim of the invention is to improve the accuracy of diagnostics of the state of pressing of the laminated core of an electric machine. Strain gauges 1, for example, of the capacitive type, are mounted on pressure pins or elsewhere outside the core after assembly and crimping of the latter. The strain gauges are connected through the switching device 2 to the current generator 3 and the measuring device 4. The generator uses a power source of a reduced frequency, for example, 1-10 kHz, which exceeds the natural frequency of the core. During the diagnostic process, the current in the strain gauge circuit is measured, and the state of pressing of the core is determined by the nature of the change. A il "from 9 (L BBO from the olerator

Description

1332467

FIELD OF THE INVENTION

mechanical engineering and can be used in Turbo and hydrogenerators.

The purpose of the invention is to improve accuracy.

FIG. Figure 1 shows a diagram for diagnosing the state of pressing of a laminated core of an electric machine; in fig. 2 - dependence of the current flowing through the strain gauge on the time at various frequencies of the oscillation of the core; in fig. 3 - dependence of the amplitude of the alternating current of the strain gauge on the pressure of the compact; Fig 4 shows the dependence of the amplitude of the current of the strain gauge on the amplitude of oscillations of the outermost sheet of the core.

Strain gauges, for example, of the capacitive type, are installed on the pressure pins or elsewhere outside the core after assembling and crimping the latter, or during operation during repair.

The strain gauges 1 are connected via a switching device 2 to a current generator 3 and a measuring device 4 (voltmeter, ammeter). The operation of the circuit is controlled by the control device 5, which ensures the interrogation of strain gauges according to a predetermined program or at the command of the operator. The circuit also contains an information processing device 6, where the pressing pressure is determined and the values are stored, and the display device 7, in which information on the state of the core pressing is displayed in the main view.

As a generator, it is used to improve accuracy, strain gauge

the power source is at a frequency that is, for example, 1-10 kHz, which exceeds the frequency of natural mechanical oscillations of the outermost sheet of the core. In the diagnostic process, the current in the strain gauge circuit is measured, the pattern of change over time shown in FIG. 2

The change in the value of the pressing pressure is determined by the calibration curve of the amplitude versus pressure of the pressing (Fig. 3), the measurement of the amplitude value of the modulating current component (Fig. 4).

The use of a higher frequency alternating current power source as a generator makes it possible to increase the measurement accuracy.

The proposed method for diagnosing the state of pressing of the laminated core allows determining the change in pressure of the pressing in the most critical area of the core during operation, which makes it possible to fix the beginning of the process of stripping in the early stages and decommissioning electrical equipment that has violations that ultimately lead to emergency situation

The implementation of the diagnostics by the proposed method allows measurements to be carried out both on the new equipment and on the equipment in operation, after non-labor-intensive equipment with the planned

stops.

Claims (1)

Invention Formula A method for diagnosing the state of pressing of the laminated core of an electric machine during operation, including measuring the parameters of strain gauges, determining, by these values, their calibration depending on the degree of pressing of the core, characterized in that stirred outside the core, connected to an alternating current source with a frequency higher than the natural frequency of the core, register the amplitude value of the modulating current component in the strain gauge circuit and determine the state of the core compaction from its change. ig.2 t X Fy Compiled by A. Voinov Editor M. Blanan Tehred V. Kadar Proofreader A. Ilyin Order 3844/52 Circulation 659 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4