JPH0410668Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention relates to a current transformer, and more specifically, an upper tank is placed above a lower tank that houses the primary and secondary coils through an insulated pipe, and a This invention relates to a high-voltage current transformer sealed with insulating oil, in which a reciprocating oil path for insulating oil is formed by a reciprocating conductor of a primary coil passing through the reciprocating conductor of the primary coil.

Conventionally, there has been a current transformer for this type of high voltage, large current circuit as shown in FIG. That is, a primary coil 1 whose outer periphery is surrounded by a main insulator 3 is connected to inner and outer oil passages 2a, 2b by a reciprocating conductor 1d that is concentrically arranged with an inner tube 1a and an outer tube 1b with open upper ends.
A vertical reciprocating oil passage 2 for insulating oil is formed, and the primary coil ring 1c of the primary coil 1 and the primary coil ring 1
The secondary coil 4 is immersed in an insulating oil 8 filled in a sealed container consisting of a lower tank 5, an insulator tube 6, and an upper tank 7, which accommodates the secondary coil 4 wound in the shape of c. The pull-out terminals 9a and 9b provided on the upper tank 7 are connecting members 10a and 10b, respectively.
It is connected to the reciprocating conductor 1d by.

With the above configuration, the primary coil 1
Each part generates heat, but in particular the inner tube 1a of the reciprocating conductor 1d becomes high temperature due to the thermal influence of the outer tube 1b.
A temperature difference occurs between the inner and outer tubes 1a and 1b, causing a thermosiphon phenomenon in the insulating oil 8, resulting in a circulating cooling effect. That is, the insulating oil 8 that has reached a high temperature in each part of the primary coil 1 rises in the inner tube 1a and enters the upper tank 7 from the upper end, and the high temperature insulating oil 8 in the upper tank 7 flows into the upper tank 7. It is cooled by dissipating heat from the surrounding wall into the atmosphere. The insulating oil 8 cooled in this way descends and flows into the oil flow path between the outer tube 1b and the inner tube 1a, and acts to cool the entire primary coil 1.

However, the degree of cooling effect due to the thermosyphon action described above depends on the difference between the temperature of the insulating oil 8 flowing into the primary coil 1 and the temperature of the insulating oil 8 flowing out, and the difference between the inlet and outlet in the upper tank 7. Height difference h ₁
Therefore, in the reciprocating conductor 1d having a double pipe structure as described above, the height difference
If you try to increase the thermosiphon effect by increasing h ₁ and increasing the temperature difference between the insulating oil flowing into the primary coil 1 and the insulating oil flowing out, the upper tank 7 will be enlarged in the height direction, and the reciprocating It becomes necessary to extend the inner tube 1a of the conductor 1d longer into the upper tank 7.

In addition, in the conventional device as described above, the amount of heat generated in the secondary coil 4 is much smaller than the amount of heat generated in the primary coil 1, and that the amount of heat generated in the secondary coil 4 is much smaller than that in the primary coil 1, and that the amount of heat is transmitted from the primary coil 1 through the main insulation 3. Since the amount of heat carried by the primary coil 1 into the upper tank 7 is much smaller than that of the primary coil 1 carried into the upper tank 7, the temperature rise of the insulating oil 8 in the lower tank 5 is equal to the temperature rise of the insulating oil 8 in the upper tank 7. It is in a comparatively low state. Therefore, the insulating oil 8 in the lower tank 5 hardly contributes to cooling the primary coil 1.
In this sense, it can be said that it is an uneconomical structure.

This idea was made in consideration of the above points, and has a simple structure in which the inlet for insulating oil to the primary coil is located in the lower tank, increasing the efficiency of the thermosiphon action and achieving a change with excellent cooling effects. The purpose is to provide a flushing device.

An embodiment of this invention will be described below with reference to FIG. An insulating sealing member 11 seals the upper end of the outer flow path 2b of the reciprocating flow path 2 formed by the reciprocating conductor 1d.
to prevent the insulating oil 8 in the upper tank 7 from flowing into the outer flow path 2b. An opening 1b-1 is provided in the side wall of the outer tube 1b near this sealing portion, and the upper end of the insulating tube 12 is connected to the opening 1b-1. The insulating tube 12 extends downward and has a lower end opening 12a.
is located near the bottom plate 5a of the lower tank 5. This opening 12a serves as an inlet for the insulating oil 8 into the outer flow path 2b. Other parts that are the same as those in FIG. 1 are designated by the same reference numerals, so their explanation will be omitted.

Next, the action and effect will be explained. The primary coil 1 is
When electricity is applied, the insulating oil 8 that generates heat and whose temperature has risen flows into the upper tank 7 and at the same time flows through the opening 12a of the insulating tube 12 to the cooled insulating oil 8 in the lower tank 5.
flows into the outer flow path 2b. In this case, the height difference h ₂ between the inlet and the outlet is significantly larger than in the conventional case, and the insulating oil 8 flowing into the outer flow path 2b is distributed between the upper tank 7, the insulator pipe 6, and the lower tank 5. Since the primary coil 1 is cooled at a sufficiently low temperature by the side walls of the primary coil 1, the cooling effect of the primary coil 1 can be significantly increased. Therefore, it is possible to realize a current transformer that can flow a larger current without changing the overall size of the current transformer.

In addition, in the above embodiment, a tubular conductor arranged concentrically was shown as the reciprocating conductor 1d, but
A similar effect can be obtained by using reciprocating conductors arranged in parallel.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional device, and FIG. 2 is a longitudinal sectional view of an embodiment of this invention. 1...Primary coil, 1a...Inner tube, 1b...
Outer tube, 1b-1...opening, 1c...coil ring,
1d... Reciprocating conductor, 2... Reciprocating oil path, 2a... Inner oil path, 2b... Outer oil path, 3... Main insulation, 4...
...Secondary coil, 5...Lower tank, 6...Insulator pipe,
7... Upper tank, 8... Insulating oil, 11... Insulating sealing member, 12... Insulating tube, 12a... Opening.
In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims for Utility Model Registration] (1) A lower tank, an insulator pipe installed above the lower tank, an upper tank attached to the upper part of the insulator pipe, and a primary coil and a secondary coil housed in the lower tank. In a current transformer having a secondary coil and a reciprocating conductor of the primary coil penetrating through the insulator tube to form a reciprocating oil passage for insulating oil, an upper end is connected to an opening at an end on an outgoing side of the reciprocating oil passage, and a lower end is opened. A current transformer characterized in that the lower tank comprises an insulating tube located at the bottom of the lower tank. (2) The current transformer according to claim 1, in which the reciprocating conductors are arranged concentrically. (3) The current transformer according to claim 1, in which reciprocating conductors are arranged in parallel.