SU205941A1 - METHOD FOR DETECTING THREADED ENCLOSURES AND ENCLOSURES ON THE HOUSING WINDINGS ANCHORING COLLECTOR ELECTRIC MACHINES WITH EQUALIZED CONNECTIONS - Google Patents

Description

The known methods for detecting short circuits and short circuits on the windings casing of collector electric machines with equalizing connections consist in that a pulse voltage is applied to the collector and the magnetic fluxes are measured with a date-scale.

In order to increase the accuracy of measurements and the shortening of time for detecting defects, it was proposed to measure the magnetic fluxes of sections connected by equalizers, and to compare them, revealed a defective section on the deviation of the magnetic flux.

FIG. 1 is a schematic diagram of a test voltage supply; in fig. 2 - electric. a circuit for measuring the magnetic flux; in fig. 3 shows the dependence of the magnetic flux on the section number when closing between turns.

When finding defects in the windings of Korea, a pulse voltage from the generator J of pulse voltages is fed to the collector 2 of the core 3 relative to the housing.

The magnetic flux of the section is measured by means of an inductive sensor connected to a measuring circuit, which is a pulse amplifier assembled according to a circuit with an open source, an emitter, the sensor takes a fixed position, and the measles rotate.

When determining a section with a coil circuit, or a circuit between the coils of adjacent sections, as well as the location of an open circuit of the winding core or a closed coil section that occurred when the sections were incorrectly installed, the induction sensor is fixed over those parts of the core sections that are located outside the groove of the core, and the sensor is installed above the section with the maximum magnetic flux. The position of the sensor is predetermined on a defect-free cortex when moving it over sections and with a stationary cortex. The gap between the sensor and the sections is 2-3 mm.

The sensors set the air gap along the turns of the section.

When finding the location of the closure to the housing, the method of applying the pulse voltage to the collector and the measuring device with the induction sensor is the same as when searching for the winding closure. An induction sensor is installed over the section on which the pulse voltage is applied to the middle turn. The sensor air gap is placed along the middle inlet of this section.

In order to find short circuits between the turns or on the case, as well as the places of incorrect connection of the turns of the sections, leading to the formation of a short-circuited turn, or embrace the magnetic fluxes of the defective section and sections connected to it by equalizers.

The circuit of the pulse amplifier of the ribs works as follows. If there is no negative polarity induced induction in the sensor L, the transistor G is locked. Capacitor C is not charged, the And indicator line is at zero. When a negative polarity pulse appears in sensor L, the indicator needle deflects by a certain number of scale divisions in accordance with the change in charge current of capacitor C, which is determined by the duration of the pulse at the amplifier output.

In the absence of a defect in the winding, the indicator readings remain constant for any section passing the node by the sensor.

This is due to the fact that any section under the sensor is characterized by the same electrical state, in particular, a constant value of the magnetic flux.

If there is a short-circuit type fault in the winding, the indicator readings change. When the core rotates 360 ° according to the indications of the indicator, sections connected by equalizers are found for which the values of magnetic flux are minimal.

The nature of the change in the magnetic flux during the passage under the sensor of the defective section and the sections associated with it by equalizers depends on which turns of the defective section are closed.

With the passage of the defective section under the sensor, the change in the magnetic flux is more dramatic (see Fig. 3 - continuous curves), - a large difference between the minimum and

maximum readings - than when passing sections connected by equalizers (dashed curves).

When short-circuited to the case, the pattern of change in the magnetic flux is the same as when finding a locking closure. The difference is that the minima of the indicator readings are deeper here (down to zero indicator).

When finding winding closures or winding closures on the case, for example, B four-pole maschiny, there are two minimum indicator readings in accordance with the equalizer step on the collector.

The described method is also acceptable for Koreans with bandages. In this case, they first make sure that there is a defect in the insulation of the winding in the same way, arranging the sensor

over the groove of the core, and then remove the bandage and proceed to find the defect.

Subject invention

A method for detecting winding short circuits and short circuits on the case of windings of Korean electrical collectors with equalizing connections by applying a pulse voltage to the collector and measuring magnetic fluxes using a sensor, characterized in that, in order to increase accuracy and reduce the time for defect detection, The magnetic fluxes of the sections connected with the bridges are equalizing compounds, and by comparing them, they reveal the defective section but the deviation of the magnitude of the magnetic flux.

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