JPS6030890B2 - Insulating oil stability test equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an insulating oil stability testing device.

Conventional insulating oil stability tests described in Test Methods ASTM D1313, ASTM D2440, and JISC2101 have been judged by the total acid number value and the amount of sludge at a specified temperature and time. Examining the oxidation stability of insulating oil through such standard tests is important in itself, but in practice, it is also important to check changes in electrical properties such as electrical resistance and yield strength during sewing until sludge appears. It is necessary to know.

This invention was made in view of the above circumstances, and is a stability test that not only allows easy detection of the total acid value and amount of sludge, but also allows accurate measurement of the electrical resistance and dielectric loss tangent of insulating oil during the oxidative deterioration process. The purpose is to provide a device.

Hereinafter, the structure of an embodiment of the insulating oil stability testing apparatus according to the present invention will be explained based on FIG. 1. In the figure,
Reference numeral 1 denotes a metal container, the inner wall of which is surface-treated with resin, glass, or the like.

Reference numeral 2 denotes a lid that covers the upper part of the container 1, and together with the container 1 constitutes a closed container 20.

3 is insulating oil stored in a certain amount in the sealed container 20; 4 is a heater provided on the outer wall of the sealed container 20 to heat the insulating oil 3; 5 is provided in the lid 2 and sealed via a valve 6. This is a V supply port that passes inside and outside the container 20, and is for supplying oxygen gas.

7 is a thermometer provided to measure the temperature of the insulating oil 3; 8 is a circulation pipe whose both ends are closed in the insulating oil 3 and circulates the insulating oil 3 therein by the action of a liquid pump 9; The coaxial cylindrical electrodes are provided in the middle of this circulation pipe 8, and include a high voltage electrode 10a formed in a cylindrical shape as shown in FIG. It consists of guard electrodes 10d attached to both ends of the low voltage electrode 10c.

Reference numeral 11 denotes an oil intake port which branches from the circulation path 8 via a valve 12, and 13 indicates a gas discharge port which flows into and out of the closed container 20 via a valve 14, and one outer end thereof is inserted into an oil reservoir 15.

Next, the operation of the insulating oil stability testing apparatus configured as described above will be explained.

First, the liquid pump 9 is operated to circulate the insulating oil 3 into the circulation pipe 8, while the valves 6 and 14 are open and the valve 12 is closed, oxygen gas is sent into the closed container 20 from the supply port 5 and the heater is heated. After heating the insulating oil 3 to the specified temperature in step 4,
A high voltage electrode 10a and a low voltage electrode 10 are formed by a coaxial cylindrical electrode 10.
The electrical resistance and dielectric support of the insulating oil 3 circulating in the gap 10b existing between

Furthermore, when the valve 12 is connected, the insulating oil 3 is inevitably discharged from the oil extraction port 11 branched from the circulation pipe 8, and is used for measuring or weighing, for example, dielectric breakdown strength, interfacial tension, chromaticity, sludge amount, etc. I can do it. This device has coaxial cylindrical electrode 1.
0 is housed in a sealed container 20, external factors such as moisture absorption and contamination that occur during oil extraction are not introduced, which has the advantage of allowing accurate evaluation of electrical characteristics. Furthermore, by recording the conduction current while applying a DC voltage to the coaxial cylindrical electrode 10', it is possible to continuously track the oxidative deterioration process of the electrical resistance. Similarly, dielectric positive bales can be continuously recorded using an automatic capacitance bridge while applying an alternating voltage. Further, as in another embodiment shown in FIG. 3, two coaxial cylindrical electrodes 10 are housed in a sealed container 20 in parallel or in series, one for measuring electrical resistance and the other for measuring dielectric positive saddle. , it is also possible to carry out continuous and simultaneous measurements. Although not shown in the drawings, it goes without saying that flowmeters for gas and insulating oil may be added as appropriate.

As explained above, the insulating oil stability testing device according to the present invention is provided with a circulation pipe to circulate the insulating oil, and by arranging an electrode in the middle of the circulation pipe, the electrical resistance and Kenro Masatoshi can be accurately measured over time. It has the effect of being able to be measured and clarifying the detailed stability of the insulating oil.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the insulating oil stability testing device according to the present invention, FIG. The figure is a schematic diagram showing the structure of another embodiment of the insulating oil stability testing device according to the present invention. In the figure, 3 is insulating oil, 4 is a heater, 5 is a supply port, 8
1 is a circulation pipe, 10 is a coaxial cylindrical electrode, and 20 is a closed container. Note that the same reference numerals in each figure indicate the same or corresponding parts. Figure 2 Figure 1 Figure 3

Claims (1)

[Scope of Claims] 1. A sealed container for storing a predetermined amount of insulating oil therein, a supply port for supplying oxygen gas into the sealed container, and a heater for heating the insulating oil to a predetermined temperature. , a circulation pipe that is disposed inside and outside of the sealed container and has both ends opened into the insulating oil to circulate the insulating oil; and an oil extraction port that is branched from the circulation path outside the sealed container;
Stability of insulating oil comprising a coaxial cylindrical electrode, which is connected to the middle of the circulation pipe inside the airtight container and consists of a cylindrical high-voltage electrode and a low-voltage electrode arranged inside the cylindrical high-voltage electrode with a predetermined gap between them. Test equipment. 2. The insulating oil stability testing device according to claim 1, comprising two coaxial cylindrical electrodes.