SU1195305A1 - Measuring cell for determining dielectric characteristics of liquid electro-insulating materials - Google Patents

Description

111

The invention relates to electrical tests of liquid electrical insulating materials and can be used to create devices for determining the dielectric characteristics of liquid dielectric materials, such as dielectric constant, volume resistivity.

The aim of the invention is to enhance the functionality by making it possible to determine the dielectric characteristics of materials at positive temperatures.

The drawing shows the designs of the measuring cell.

The measuring cell contains a high-voltage electrode 1, made in the form of a cylindrical glass, inside which the measuring electrode 2 is placed with a corresponding gap, also made in a cylindrical glass, the axial arman of Sv as a hollow cylindrical rod, closed on one side and placed on the vertical axis of the cell. A thermometer 4 is placed inside the axial pocket 3. At the ends of the measuring electrode 2, the first 6 and second 7 cylindrical guard electrodes are placed through insulating insulation pads 5. Vy shackles OLD electrode 1 is provided with a cylindrical winding 8 of induction heating, placed across the entire height of its outer side surface. In the cavity: between the pocket 3 and the measuring electrode 2 along the entire height of the inner surface of the latter is placed the heating element 9 in the form of concentric back. rally. In the axial pocket 3 is placed a liquid 10c with high thermal conductivity, for example, transformer oil. The test fluid 11 is in the cavity, which is formed by the gap between the high-voltage 1 and measuring 2 electrodes.

For convenience, the measuring cell contains flushing drain valve 12. The measuring wires are connected to screw terminals (not shown) mounted on electrodes 1 and 6. The wire is connected to electrode 2 through a special hole in electrode 6. The connecting wire and

052

I clamp the measuring electrode 2 is electrically isolated from the electrode 6.

In the construction of the measuring cell, n-heating occurs uniformly

throughout the cell volume. In this case, the measuring 2 and the guard 6 and 7 electrodes are heated by the heating element 9, and

high voltage electrode 1 - at the expense of. losses created by eddy currents from the winding 8 induction heating.

Measuring cell allows

make tests to determine the dielectric characteristics of liquid electrically insulating materials at positive temperatures. And compared to using

for these purposes, a known measuring cell placed in a thermostat, the proposed cell provides a higher heating rate of the test material, which

important when testing wetted isolation. This is explained by the fact that in a thermostat heating is carried out by transferring heat from its walls by means of air convention to

measuring cell, and in the proposed cell - due to the heating elements combined structurally with the cell. In this case, the cell mass with a thermostat is significantly higher than the mass of the cell proposed, therefore, the heating efficiency in the proposed measuring cell is higher than that in the thermostat,

In addition, the measured temperature data inside the proposed measuring cell is more reliable than when measuring the air temperature in the thermostat.

Claims (1)

Invention Formula Measuring cell for determining dielectric characteristics of liquid electrical insulating materials containing high-voltage an electrode made in the form of a cylindrical cup, inside which a measuring electrode, also made in the form of a cylindrical cup, is placed with a corresponding gap, axial pocket in the form of a hollow cylindrical rod, closed on one side, placed along the vertical axis of the cell, inside the axial frame- i. 3 11 mana a thermometer, a cylindrical guard electrode, is placed, and the gap between the high-voltage and measuring electrodes forms a cavity for the test material. characterized in that, in order to expand the functionality by making it possible to determine the dielectric characteristics of materials at positive temperatures, it is equipped with a heating element and a second protective cylindrical electrode, and the high-voltage electro-05 type is equipped with a cylindrical induction heating winding placed along its entire height the surfaces, the first and second protected cylindrical electrodes are placed at the ends of the measuring electrode through insulating setting, the heating element is made in the form of a concentric spiral placed in the cavity between the pocket and the measuring electrode over the entire height of the inner surface of the latter; in the axial pocket is placed a liquid with high thermal conductivity.