Technical Field

The present invention relates to the field of the transformer cooling. The heat applied to the transformer is divided into 2 components, the inner heats and the outer heats, largely. The inner heats come from winding loss and core loss in operation of the transformer and the outer heats are divided into 2 components, the heat from ambient air and the heat from the sunshine. The rise of the temperature by the sunshine is not considered in the design of the transformer but that by the ambient air is considered. The rise of the temperature by the sunshine is severe to the transformer operating in the outdoor. So the present invention suggests the countermeasure for the sunshine effects to the facility like as the outdoor transformer.

Background Art

The maximum temperature rising for the ambient air is supposed about 40 °C in the design of the transformer. This supposition is reasonable roughly. But in case of the outdoor transformer that is beaten by the sunshine in the summer the rise

of the temperature of the insulating oil is able to excess 40 °C and the countermeasure for the sunshine effects must be prepared. The rise of the temperature of the insulation oil for the sunshine can offer the serious effects on the safety in operating to the outdoor transformer, specially, in the equatorial region where the intensity of the sunshine is very strong. The problem of the effects of the sunshine to the outdoor transformer is not treated in the ANSI codes that are in common use in the world.

Disclosure of Invention

Summary of the Invention

The transformer is designed in the supposition that the maximum rise of the temperature of the insulation oil for the ambient air is 40 °C. But the temperature of the metal exposed in the sunshine rise to about 75 °C and that of the insulation oil in the metal body excess 40 ^° C in summer when the intensity of the sunshine is strongest. The pole transformer whose guaranteed span of the life is 30 years is replaced in 15 years generally in

Korea. The present invention suggests the shading that makes smooth ventilation to emit the inner heat of the transformer and gives the shade to the transformer by the effective intercepting of the sunshine. The present invention suggests two types of the

shading, the type of the teeth of a comb and the type of the two intersection planes. The shading of the large plane type is installed on the part of the transformer tank whose shape is like as a plane. The shading of the bundle of several small separated shadings is installed on the part of the transformer tank whose shape is complex. In case that the shape of the transformer tank is cylindrical like as a pole transformer the two of the half cylindrical type shading and the shield type shading is suggested.

Detail description of the Invention

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1. illustrates the shading of the teeth of a comb. The shading of the teeth of a comb 11 is composed the frame and the teeth of a comb 13 that are installed in the frame in uniform interval in parallel. The teeth of a comb 13 intercept the sunshine but pass the air. The teeth of a comb 13 can be installed horizontally or in inclination to the horizontal plane. The bolt frames 12 that fix the shading of the teeth of a comb 11 are installed minimum 6 in the part of the upper right, middle and left and in the part of the lower right, middle and left. The bolt frames 12 can be installed in the inner part of the shading for the fine sight. The shading of the teeth of a comb 11 is made in the type of

the plane to fit to the shape of the part to be fixed. The shading of the bundle of several small separated shadings is installed on the part of the transformer tank whose shape is complex. The material of the shading of the teeth of a comb 11 shall be metal, plastics, wood, FRP(Fiberglass Reinforced Plastics) and etc.. In case the material is metal the adiabatic is installed between the transformer and the shading to prevent conduction of the heat from the shading to the transformer. The color of the shading can be chosen diversely to be harmonious to the surroundings. We can fix the shading by inserting the projection for fixing (not illustrated) to the bolt hole 33 in Fig 3. instead of the bolt frame 12.

FIG 2. explains the shading of the type of the two intersection planes. The shading of the two intersection planes 21 is the other type of the shading. The shading of the two intersection planes 21 is composed the frame, the front plane and the rear plane. The several front draft holes 22 are made in the front plane. The several rear shading plane 23 are installed in the rear plane to prevent the sunshine passed through the several front draft holes 22. So the air can pass the shading but the sunshine shall be intercepted. The several round shape holes can be substitute for the several front draft holes 22. The bolt frames 12 that fix the shading of the two intersection planes 21 are installed minimum 6 in the part of the upper right, middle and left and in the part of the lower right, middle and left. The bolt frames

12 can be installed in the inner part of the shading for the fine sight. The material of the shading of the two intersection planes 21 shall be metal, plasties, wood, FRP(Fiberglass Reinforced Plasties) and etc.. In case the material is metal the adiabatic is installed between the transformer and the shading to prevent conduction of the heat from the shading to the transformer.

FIG 3. explains the sticking bar for the small separated shadings. The pipe type sticking bar 31 is the form of the rectangular pole. The several bolt holes 33 are installed on a side of the sticking bar 31. And the nut injection holes 34 are installed on the right and left side of the sticking bar 31 to match the bolt holes 33. The intersection of the U-type sticking bar 32 is capital U. Except the shape of the intersection the others are the same to the pipe type sticking bar 31. FIG 4. explains the example of the small separated shading installed on two of the sticking bars. Two of the sticking bars are arranged under each of the right and the left side of the small separated shading, and the bolts 41 are inserted through the bolt frame 12 of the small separated shading and the bolt hole 33, and the small separated shading is fixed on the sticking bars by the nuts finally.

FIG 5. illustrates the example of the small separated shading installed on the facility directly. The small separated shading can be installed on the facility directly to intercept the

sunshine if there is no reason to use the sticking bar. In case of nut sticking type the sticking nut 52 is installed on the facility 51 and the bolt 41 is inserted through the bolt frame 12 of the small separated shading and the sticking nut 52, and the small separated shading is fixed on the facility 51. In case of magnet sticking type the magnet joint bolt 54 is inserted through the hole in the center of the circular magnet 53, the bolt frame 12 of the small separated shading and the nut 42, and the small separated shading is fixed on the facility 51. FIG 6. illustrates the ground plan to explain sticking method of the shading to the radiator. There are two of the insulation oil pipes 43 between the radiator and the transformer, so the insulation oil inflows and outflows through them. First we locate the shading of the teeth of a comb 11 or the shading of the two intersection planes 21 in front of the radiator. We surround the last plane of the radiator with the round side of the U-bolt 61 and insert the other side to the bolt frame 12 of the shading and sticking the shading to fix the nuts 62 at the end of the U-bolt 61. The spacer 63 is located between the shading and the radiator. We make this process two times on the upper side and the lower side.

We substitute the band or the binder for the U-bolt 61.

FIG 7. illustrates the front side of the cylinder type shading. The cylinder type shading 71 is suit for the transformer that has a cylinder type tank like as pole transformer. The cylinder type

shading 71 has the shading plane like as the shading of the teeth of a comb 11 or the shading of the two intersection planes 21. The cylinder type shading 71 are composed two of the half cylinder type shadings and these two of the half cylinder type shadings are combined with the band 75 inserted in the hole of the combination band 74 or binder. The bushing hole 72 is made on the upper side to pass the high voltage bushing and the low voltage line hole 73 is made on the front side to pass the low voltage lines. The sunshine beat on the upper side is severest. So we can modifies the cylinder type shading 71 to have only the upper side and some flank to intercept the sunshine on the upper side and the some of the flank. FIG 8. illustrates the rear side of the cylinder type shading. We make the hanger of the pole transformer pass the cylinder type shading 71 through the rear side. FIG 9. illustrates the example of the installation of the shading to the substation transformer. We can select the region to intercept the sunshine like as radiator or upper side of the tank. To intercept the upper side sunshine is very effective because the temperature of the insulation oil at upper side of the tank is highest. The reason is that the heated insulation oil comes up to the upper side because the density becomes light and the sunshine to beat the upper side of the tank is strongest. So the shading can be installed only on the upper side of the transformer and the power system facility.

FIG 10. illustrates the example of the installation of the shading to the PAD transformer. The PAD transformer(Pad mounted transformer) constructed on the road side in the urban region has a plane type outward form. So large plane type shading can be installed on the PAD transformer.

The shading for the transformer is treated generally from FIG 6 —FIG 10. The shading can be applied to the other power system facility 51 with the same methods.

Brief Description of Drawings

FIG. 1. illustrates the shading of the teeth of a comb.

FIG 2. explains the shading of the type of the two intersection planes. FIG 3. explains the sticking bar for the small separated shading.

FIG 4. explains the example of the small separated shading installed on two of the sticking bars.

FIG 5. illustrates the example of the small separated shading installed on the facility directly.

FIG 6. illustrates the ground plan to explain sticking method of the shading to the radiator.

FIG 7. illustrates the front side of the cylinder type shading.

FIG 8. illustrates the rear side of the cylinder type shading.

FIG 9. illustrates the example of the installation of the shading to the substation transformer

FIG 10. illustrates the example of the installation of the shading to the PAD transformer.

Description of the number of the Drawings

11 : shading of the teeth of a comb

12 : bolt frame 13 • the teeth of a comb 21 : shading of the two intersection planes

22 : front draft hole 23 : rear shading plane

31 : pipe type sticking bar 32 •' U- type sticking bar

33 : bolt hole 34 •" nut injection hole

41 bolt 42 : nut

51 •' facility 52 • ^* sticking nut

53 : circular magnet 54 • magnet joint bolt

61 : U-bolt 62 : nut

63 : spacer 64 : pole transformer

71 •' cylinder type shading 72 : bushing hole

73 • low voltage line hole

74 • hole of the combination band

75 - band 76 : PAD transformer

Best Mode for Carrying Out the invention

The example illustrated in FIG. 9. is the representative application. The shading is one of the two, the shading of the teeth of a comb type or the shading of the two intersection planes 21.

We can select the region to intercept the sunshine like as radiator or upper side of the tank. The fixing method of the shading to the transformer strongly against the severe wind like as a typhoon is necessary.

Industrial Applicability

The shading according to the present invention is very useful because it does not use any energy to cool the transformer or the power system facility. The rise of the temperature of the insulation oil for the sunshine is not considered in the design of the transformer. The shading intercepts the sunshine beaten on the transformer or the power system facility passing the air through it. We have confirmed that the difference of the temperature of the insulation oil of the two transformers, one that a shading is installed on and the other that a shading is not installed on, is large, about 15 ^° C .