JPH0242707A - Stationary induction apparatus - Google Patents

Abstract

PURPOSE:To provide a stationary induction apparatus which is economic and capable of insulating and cooling windings in a desirable manner and has high reliability for insulation properties by arranging a cooling duct within an iron core and circulating a cooling medium in the cooling duct. CONSTITUTION:A metallic hollow cooling duct 20 is provided within an iron core 3 and a cooling medium 21a is enclosed in the cooling duct 20. Inner and outer windings 4 and 5 are wound on the outer periphery of the iron core 3. These windings 4, 5 are received in a container 22 and the same cooling medium 21b as the cooling medium 21a is enclosed in the container 22. Both the cooling media 21a are 21b are fed to a cooling device 24 arranged outside the container 22 and circulated by feeding pumps 23a and 23b, respectively. The container 22 containing the iron core 3 and the windings therein is further received by a tank 27 having an insulating medium 26 enclosed therein. According to such arrangement, it is possible to obtain a stationary induction apparatus which is economic and capable of insulating and cooling the windings 4 and 5 desirably and has high reliability for insulation properties.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a stationary induction device that cools components by circulating a cooling medium.

(Prior technology) In recent years, there has been an increasing need for static induction equipment such as transformers and reactors to have higher voltage and larger capacity, and in order to reduce the installation area, it is desirable to downsize and downsize the equipment. It is rare.

Furthermore, in recent years, from the viewpoint of disaster prevention, insulating gases such as SF6 gas have been used as insulating media and cooling media to make equipment nonflammable. However, S
Insulating gases such as F6 gas have the same or better insulating properties than insulating oil, or have lower specific heat and specific gravity, and inferior cooling properties.

Therefore, in large-capacity equipment, SF6 gas is forcibly circulated to cool the core, windings, etc., but as the gas flow rate increases, the head loss in the flow path also increases.
It is necessary to suppress it to about several m/SeC. Therefore, there is a limit to the improvement of the cooling effect, and the cooling performance is generally several times lower than that of insulating oil.

Therefore, as a means to solve the above points, SF6 gas and a nonflammable liquid with a boiling point of about 100'C or less are used together, insulation is mainly performed by SF6 gas, and cooling is mainly performed by nonflammable liquid. There is a method. In this method, a non-flammable liquid (e.g. CFC) is sprayed onto loss-generating parts such as iron cores and windings, and when it comes into contact with high-temperature loss-generating parts, the latent heat of vaporization that evaporates is utilized to efficiently heat the parts. is carried out outside.

Figure 2 shows an example of such stationary guidance equipment.

That is, an iron core 3, an outer winding 4, and an inner winding 5 are housed in the transformer tank 1, and a nozzle 6 is disposed above them and on the outer peripheral side. A nonflammable liquid 9 stored at the bottom of the tank is supplied to this nozzle 6 by a pump 8 via a vibrator 7, and is sprayed onto the iron core 3, windings 4.5, etc., which are heating elements.

Further, the transformer tank 1 is connected to a heat exchanger 2 provided outside thereof. Then, the nonflammable liquid sprayed within the transformer tank 1 comes into contact with the high temperature part of the heating element and partially evaporates, at which time it absorbs heat from the high temperature part and cools it. Meanwhile, the steam enters the heat exchanger 2, where it transfers heat to the outside of the tank and returns to liquid. This liquid and the liquid that has flowed down without evaporating along the surface of the heating element returns to the bottom of the tank. In this way, the nonflammable liquid is continuously circulated by the pump 8 for cooling.

(Problems to be Solved by the Invention) However, in the conventional stationary guidance equipment having the configuration as described above, there were problems to be solved as described below.

In other words, in the cooling structure described above, the non-flammable liquid is reliably dispersed only in the upper part of the iron core 3 and the windings 4 and 5 where the loss occurs, which is within the range where the liquid directly reaches from the nozzle. However, in the lower part of the iron core 3 and inside the inner winding 5, it was only expected that the liquid sprayed from the upper nozzle would flow down and perform cooling. Therefore, in practice, as described below, there was a drawback that the liquid did not reach enough.

That is, as shown in FIG. 3, the case where the inner winding 5 is a disk winding will be explained. On a rail 12 disposed outside the insulating tube 11, sections 13 each formed by winding a wire are provided in multiple stages in the axial direction with spacers 14 interposed therebetween.
An insulating cylinder 15 for the outer winding 4 is provided on the outside thereof.

In such a winding structure, when a liquid is sprayed from above by the nozzle 6, the liquid contacts each strand at the top of the winding, evaporates, and flows down as shown by the dotted line while reducing the amount, but it is certain that the liquid is not liquid. The portions that come into contact with the strands are the strands near the inside and outside of each section 13 indicated by the symbol A, and the liquid does not sufficiently reach the strands located in the middle of the sections 13.

In particular, this tendency is stronger the lower the section is, the cooling efficiency becomes worse, and the temperature becomes higher than that of the square section.

Therefore, the temperature locally becomes high, which causes the insulation to deteriorate easily. Therefore, since it is necessary to limit the maximum temperature, the winding must be manufactured while keeping the temperature rise of the entire winding low, resulting in an uneconomical winding. Furthermore, since the maximum temperature was uncertain, it could not be said to be highly reliable.

On the other hand, cooling media such as chlorofluorocarbons are expensive, and using them to cool and insulate the entire transformer is very expensive and also has the drawback of being heavy.

Furthermore, cooling the iron core 3 at the same time using a cooling medium that cools the windings will result in foreign matter contained within the iron core being mixed into the cooling medium circulating within the windings, resulting in a particularly high electric field.・The insulation performance inside the winding was significantly reduced.

The present invention was proposed to solve the above-mentioned drawbacks, and its purpose is to provide an economical stationary induction device that has excellent winding insulation and cooling performance, is economical, and has high insulation reliability.

"Structure of the Invention" (Means for Solving the Problems) The present invention provides a stationary induction device comprising an iron core and a winding housed in a tank. A cooling duct is provided, and the winding is housed in a container together with a cooling medium, and both cooling mediums are circulated through a cooler provided outside to cool the core and the winding. The container containing the insulating medium is housed in a tank together with an insulating medium.

(Function) According to the stationary induction device of the present invention, by disposing a cooling duct in the iron core and circulating a cooling medium inside the duct,
Since the core portion can be cooled, foreign matter contained in the core can be prevented from entering the cooling medium.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIG. Note that the same members as those of the conventional type shown in FIGS. 2 and 3 are designated by the same reference numerals, and explanations thereof will be omitted.

In this embodiment, as shown in FIG. 1, a hollow metal cooling duct 20 is built inside the iron core 3, and a cooling medium 21a is sealed inside the cooling duct 20.

Further, an inner winding 4 and an outer winding 5 are wound around the outside of the iron core 3, and these windings are housed in a container 22, in which a cooling medium 21b same as the cooling medium 21a is sealed. There is. These cooling mediums 21a and 21b are
Both liquids are sent to an externally disposed cooler 24 by liquid sending pumps 23a and 23b, and are configured to circulate.

Further, the container 22 housing the iron core 3 and the windings is a tank 2 in which an insulating medium 26 such as SF6 gas is sealed.
It is housed in 7.

In the stationary induction device of this embodiment having such a configuration, the core and windings are cooled as described below. That is, the windings 4.5 that generate heat are cooled by the cooling medium 21b that has an excellent cooling function, and the cooling medium 21b that has taken away heat is sent to the cooler 24 where it is cooled and circulated. , sent to the winding section.

On the other hand, the heat generated in the iron core 3 is cooled by heat conduction through a cooling duct 20 disposed inside the core 3. At this time, both the cooling media 21a and 21b can cool the windings and the iron core without coming into direct contact with the iron core.

Further, the windings 4.5 are cooled and insulated at the same time by a cooling medium 21 having an insulating property, and the windings 4, 5 and the tank 27 are further insulated by an insulating medium 26 such as SF6 gas.

As described above, according to this embodiment, the cooling of the core 3 portion where the generation of foreign matter has been a problem is achieved by circulating the cooling medium 21a in the cooling duct 20 disposed inside the core 3. Cheap items in the iron core 3 can be prevented from getting mixed into the cooling medium 21a.

Furthermore, if the cooling medium 21b sealed in the container 22 containing the windings 4 and 5 is a nonflammable medium, and the insulating medium stored in the tank 27 is also a nonflammable insulating medium such as SF6 gas, the entire transformer Can be made nonflammable. In addition, by using a cooling medium with excellent insulation properties such as insulating oil as the cooling medium 21 in the container 22, insulation becomes easy and the insulation performance is improved.
Stability is also improved.

Furthermore, the cooling medium 21 stored in the container 22 is
．． 5 and the iron core 3 can be effectively cooled, the amount can be minimized, so the cost of the transformer can be reduced, and the weight of the transformer can also be reduced. Therefore, the separate device can be made smaller and lighter, reducing loss and increasing efficiency. Furthermore, since the cooling medium is circulated, the cooling efficiency is increased, the amount of the cooling medium is small, and there is no need to replenish the cooling medium during operation, making maintenance easy.

Note that the insulation between the part of the container 22 that goes outside and the tank 27 is provided by an insulating medium 26 such as SF6 gas.
This insulating medium 26 only needs to have excellent insulating performance. For example, if steam is generated from the cooling medium 21 and mixed into the gas,
Even if the cooling efficiency of the gas decreases, it will not have the same effect as long as the insulation performance is maintained.

In addition, since the windings 4 and 5 and the iron core 3 are immersed in the cooling medium 21, the gas pressure in the tank 27 does not increase, and maintenance protection devices such as a conservator are simplified.
Reliability is also improved.

*Sen's Embodiment* Note that the present invention is not limited to the embodiments described above, and the cooling medium 21 may be a nonflammable cooling medium such as condensable or non-condensable perfluorocarbon, or a nonflammable cooling medium having a cooling function. Something like insulating oil may also be used.

Further, the container 22 that stores the windings 4 and 5 may be an integrally molded product made of reinforced plastic FRP or the like, or may be an airtight combination of an inner cylinder, an outer cylinder, and a bottom plate, but a part of the container 22, for example, is open at the top. However, the cooling medium 21 may be configured so as to escape to the tank side as a vapor or a part of it as a liquid.

Alternatively, the windings 4 and 5 may be stored and divided into separate containers.

[Effects of the Invention] As described above, according to the present invention, hollow cooling ducts 1 through which a cooling medium circulates are disposed in the iron core,
Further, the winding is housed in a container together with a cooling medium, and both cooling mediums are circulated through a cooler provided outside for cooling. At the same time, by simply storing it in a tank, it is possible to provide an economical stationary induction device with excellent winding insulation and cooling performance, and high insulation reliability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a static induction device of the present invention, FIG. 2 is a configuration diagram of a conventional static induction device, and FIG. 3 is a detailed view of a coil portion. DESCRIPTION OF SYMBOLS 1... Transformer tank, 2... Heat exchanger, 3... Iron core, 4... Outer winding, 5... Inner winding, 6... Nozzle, 7... Pipe, 8...Pump, 9...Nonflammable liquid, 11...Insulating tube, 12...Rail, 13...
...Section, 14...Spacer, 15...Insulating tube, 20...Cooling duct, 21a, 21b...Cooling medium, 22...Container, 23a. 23b...Liquid pump, 24...Cooler, 26...
- Insulating medium, 27...tank.

Claims (1)

[Claims] A stationary induction device comprising an iron core and a winding housed in a tank, wherein a hollow cooling duct through which a cooling medium circulates is provided in the iron core, and the winding The wire is housed in a container together with a cooling medium, and both cooling mediums are circulated through a cooler provided outside for cooling, and the container housing the core and the winding is housed in a tank together with an insulating medium. A stationary guidance device characterized by being housed in a.