JPS6359256B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to electrical equipment, particularly to the construction of electrical equipment such as oil-immersed transformers with increased short-term overload capacity.

FIG. 1 is an overall configuration diagram of a conventional oil-immersed transformer of this type. In the figure, 1 is a main body container which houses a transformer main body 4 consisting of a winding 2 and an iron core 3 and insulating oil 5, and 6 is a main body container 1 that is connected to the main body container 1 through piping 8 along with a pump 7, and is connected to the main body container 1 through piping 8. This is a cooler that cools the 5.

In a conventional oil-immersed transformer configured as described above, the loss generated during continuous rated load of the transformer body 4 is usually taken into consideration, and the temperature of the winding 2, etc. at that time is kept within a predetermined limit. The capacity of the cooler 6 is set, and steady operation of the transformer is maintained.

However, the conventional oil-immersed transformer as described above has the following drawbacks, especially when overload operation is imposed. That is, when the transformer shifts to overload operation, the temperature of the winding 2 rises from its equilibrium temperature, which accelerates thermal deterioration of the insulating paper (not shown) wrapped around the winding 2, causing the transformer to deteriorate. The drawbacks were that the operating life was shortened and the overload capacity could not be increased. Furthermore, if a large capacity transformer with an overload capacity is installed in order to prevent the above thermal deterioration, the transformer as a whole becomes extremely expensive, which is also economically disadvantageous.

This invention was made to eliminate the drawbacks of the conventional ones, and includes a refrigerant container that is connected to the main container via a control valve and contains refrigerant, and the control valve is opened during overload operation. It is an object of the present invention to provide an electrical device that can suppress a rise in the temperature of the main body of the device during overload operation and increase the overload capacity by mixing the refrigerants in both containers.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is an overall configuration diagram of an oil-immersed transformer in an embodiment to which the present invention is applied. In the figure, main body container 1, winding 2, iron core 3, transformer main body 4
The insulating oil 5, cooler 6, pump 7, and piping 8 are the same as in the conventional case, so their explanation will be omitted. Reference numeral 9 denotes a container containing insulating oil 10, and 11 a control valve arranged to connect main container 1 and container 9 via piping 12, which is operated by electromagnetic operation etc. during overload operation of transformer main body 4. It will be released.

Next, the operation of the oil-immersed transformer as an embodiment of the present invention configured as described above will be explained. First, during steady operation, the insulating oil 5 is maintained at a predetermined temperature rise by the cooler 6, and the operation of the transformer body 4 is maintained. At this time, the control valve 11 is in a closed state, and the insulating oil 10 is not affected by the heat generated by the transformer body 4 and maintains a temperature substantially close to the ambient temperature. Here, when the transformer main body 4 shifts to overload operation, the control valve 11 is opened via, for example, a means (not shown) for detecting the load current, and the insulating oil 5 present in the main body container 1 is opened. The insulating oils 5 and 10 in both containers 1 and 9 are mixed due to the pressure difference or density difference, and the insulating oil 5 in a high temperature state is cooled by the insulating oil 10 in a low temperature state. That is, the same effect as when a cooler corresponding to the heat capacity of the insulating oil 10 is added can be expected, and in particular, short-term overload operation can be made possible without loss of life. Note that when the overload operation returns to normal operation, the control valve 11 is operated to the closed state again, and the insulating oil 10, which has reached a high temperature, is cooled down from the outer surface of the container 9 over a long period of time. Therefore, overload capacity can be increased without adding or increasing a cooler, which is generally expensive.

FIG. 3 is a block diagram showing the entire structure of an oil-immersed transformer according to another embodiment of the present invention, in which reference numeral 13 denotes an oil pump inserted into the connection between both containers 1 and 9; It is operated when the is opened, and both insulating oils 5,
10 can be mixed quickly and efficiently. Reference numeral 14 denotes a cooler connected to the container 9 via a pipe 15, which cools the insulating oil 10 which has reached a high temperature more rapidly. With this configuration, it is possible to shorten the overload operation cycle and further increase the overload capacity.

FIG. 4 is a block diagram showing the entire structure of an oil-immersed transformer according to yet another embodiment of the present invention, in which 14 is placed in a container 9 and is insulated by evaporating the condensable refrigerant sealed therein. an evaporator that absorbs the heat of the oil 10; a compressor 15 that compresses the evaporated refrigerant;
16 is a condenser that liquefies the compressed refrigerant and releases heat to the outside air; 17 is a pressure reducing valve that reduces the pressure of the refrigerant from the condenser 16 and sends it to the evaporator 14;
The evaporator 14, compressor 15, condenser 16, and pressure reducing valve 17 constitute a refrigerator 18. With this configuration, the temperature of the insulating oil 10 during steady operation can be lowered to below the ambient temperature. That is, compared to the embodiment shown in FIG. 3, the temperature difference between the two insulating oils 5 and 10 can be made larger, and the overload capacity can be further increased.

In addition, in each of the above embodiments, the case where the application is applied to an oil-immersed transformer has been explained, but the application is not limited to transformers, but can be widely applied to electrical equipment having a heat generating part such as a reactor, and the refrigerant is not limited to insulating oil. It may be in gaseous form.

As explained above, this invention includes a refrigerant container connected to the main container via a control valve and containing refrigerant, and when the control valve is opened during overload operation to mix the refrigerants in both containers, This has the effect of suppressing a rise in the temperature of the device body during overload operation and increasing overload capacity.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the entirety of a conventional oil-immersed transformer. Fig. 2 is a block diagram showing the whole of an oil-filled transformer in an embodiment to which this invention is applied. Fig. 4 is a block diagram showing the entire oil-immersed transformer according to another embodiment of the present invention. In the figure, 1 is a main body container, 4 is a transformer main body as a main body container, 5 and 10 are insulating oils as refrigerants, 9 is a container as a refrigerant container, and 11 is a control valve. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. A device comprising a main body that generates heat, a main body container containing a refrigerant, and a refrigerant container containing a refrigerant connected to the main body container via a control valve, An electrical device characterized in that the control valve is opened during overload operation to mix the refrigerants in both containers. 2. The electrical equipment according to claim 1, wherein the refrigerant in both containers is insulating oil.