SU1492260A1 - Device for monitoring humidity of liquid dielectrics - Google Patents

Abstract

The invention relates to a measurement technique and can be used to control the quality of liquid dielectrics. The purpose of the invention is to improve the accuracy of control. The two-electrode sensor 1 is immersed in the test liquid dielectric. The electrodes 2 of the two-electrode sensor are connected to a test voltage source, which is measured at the time of the test with a voltmeter 3. The electrodes 2 are simultaneously pole tips of an electromagnet with a core 4 of magnetodielectric. The combination of the functions of the electrodes 2 and pole pieces makes it possible to combine the directions of the vectors of the electric and magnetic fields in the sample zone, which leads to the achievement of the objective of the invention. 3 il.

Description

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The invention relates to a measurement technique and can be applied in various fields of industry where continuous humidity control is required.

The aim of the invention is to increase the reliability of controlling the moisture of a liquid dielectric.

Figure 1 shows the device; Fig. 2 shows the dependence of the spread of the breakdown voltage values on the strength of the magnetic field; fig. 3 are graphs of the dependence of the breakdown voltage on the humidity of turbine oil.

In the graphs (Fig. 3), the solid field is limited by the spreading voltage of the breakdown voltage without a magnetic field, by dashed lines - The breakdown voltage field of the breakdown when exposed to a magnetic field of 600 kA / m, the intensity vector of which is perpendicular to the stress vector the electric field is limited by the dash-dotted lines to the field, the voltage spread of the breakdown when exposed to a magnetic field of 1800 kA / m, the intensity vector of which coincides with the intensity field of the electric field.

The device for monitoring the moisture content of liquid dielectrics (Fig., 1) contains a two-electrode sensor I with a spacing d between electrodes 2, which should not be less than 0.5-0.7 mm, since with a smaller distance there is a distortion of the readings, caused by accidental contamination of the dielectric under investigation. A two-electrode sensor 1 is connected to a measuring device 3, for example, a voltmeter, and a voltage source. The sensor electrodes 2 are simultaneously pole tips of a permanent magnet or electromagnet, for which the electrodes are made of a magnet of a soft material. In order to avoid short-circuiting of the voltage source along the magnetic circuit, the pole tips are closed with a core 4, filled with a magneto-electrician.

The device works as follows

A two electrode sensor 1 (FIG. 1) is placed on a controlled dielectric liquid and is supplied with a voltage.

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The measurement of the breakdown of a controlled dielectric is measured by a voltmeter 3 and the humidity of the dielectric is determined from the pre-built dependence of the breakdown voltage on the humidity of the dielectric under study (Fig. 3) and the magnetic field strength.

For example, to determine the moisture content of a turbine oil, a two electrode sensor 1 with a distance between electrodes of 0.5 mm is placed in the dielectric under study and a voltage is applied. The voltage of a sample of a controlled dielectric is measured by a voltmeter, and according to a pre-plotted plot of the magnitude of the breakdown voltage as a function of humidity when a magnetic field is applied, the degree of humidity is determined

The scatter of the voltage of the breakdown at a constant humidity of the dielectric and a constant distance between the electrodes depends on the intensity of the magnetic field (Fig. 2), ".

Without combining the directions of the vectors of the electric and magnetic fields, the distance between the pole tips of the magnet is less than 5-7 mm. At this distance, you can get a magnetic field strength of up to 600 kA / m. the gap on the surface of the magnets,

When measuring the voltage of a 4.5 kV dielectric breakdown, this breakdown voltage corresponds to a moisture content of a liquid dielectric of 0.3 ± 16% (point s-s, Fig. 3). For repeated effects of a voltage on the dielectric under test, the voltage is 3% has a spread of ± 12% of the mean (points a-a). By reducing the distance between the pole tips of the magnet to 0.5-0.7 mm, a magnetic field strength of 1800 kA / m is obtained. In this case, a measured breakdown voltage of 4.5 kB corresponds to a humidity of 0.3313%, point ( in-in). With repeated effects of voltage on the dielectric under study at a humidity of 0.33%, the spread of the voltage across the sample is reduced to ± 3% of the average value.

When the electrodes are combined with the poles of the magnets, the

Reliability of moisture control of LID insulators with similar parameters of the magnetic system.

Claims (1)

Invention Formula A device for monitoring the moisture content of liquid dielectrics containing a voltage source, the output of which is connected to a two-electrode sensor and a voltmeter input, a source of magnetically broken. mol w KB and A capacitance for a liquid dielectric, inside which is placed a two-electrode sensor, characterized in that, in order to increase the reliability of the control, the source of the magnetic field is made in the form of a magnetic circuit from a magnetodielectric, the electrodes of a two-electrode sensor are made in the form of pole pieces and fixed on the magnetic conductor.  3.0 2.0 1.0 About 600 1200 that zoo m / m srig.2. cd vibe / knotted 1.5  0.2 0.3 4f as% fpuz.S Compiled by V.Stepankin Editor. O.Yurkovetskaya Tehred M. Didyk Order 3870/46 Circulation 789 Subscription VNIIPI State Committee on Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, 4/5 Raushsk nab. Lladmos / f Proofreader K.Vasilyeva