KR830000506Y1 - Electric induction device - Google Patents

Abstract

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Description

Electric induction device

1 is a perspective view of the induction apparatus according to the present invention.

2 is a partial front view of an upper core brace structured according to another embodiment of the present invention.

3 is a cross-sectional view taken along line III-III of FIG.

4 is a partial front view of a lower core brace constructed in accordance with another embodiment of the present invention.

FIG. 5 is a cross-sectional view of FIG. 4 taken along the line VV. FIG.

The present invention relates generally to an electric flow device, and more particularly to a support structure of an electric induction device such as a transformer.

In the conventional structure of an electric induction device such as an electric transformer, the magnetic core is generally arranged in the axial direction of the electrical windings or coils, and the magnetic core is generally one or more legs in which the electrical windings or coils are arranged in the axial direction. It consists of the up and down yoke to connect. The magnetic core is formed of a lamination lamination of magnetic material which maintains the assembled relationship by the upper and lower frames arranged respectively along the upper and lower yokes.

In drying transformers such as cores and coil assemblies with a rectangular cross-sectional structure, additional side braces or end plates are connected between the upper and lower frames, and the rectangular winding moves due to stresses generated in short circuit or transient conditions. It is arranged adjacent to the outer side of the electrical winding device to prevent it from being rounded or rounded. As shown in U.S. Patent No. 3,792,395, which is patented to Mr. Mitchell and assigned to the assignee of the present application, such end plates of thick steel are welded to the frame of the upper and lower ends adjacent to the opposite ends of the coil assembly for rigid support. Form a structure.

Although endurance is satisfactory in operation, in view of the fact that higher voltages are now required and therefore higher ratings of electrical devices such as transformers, such endplate structures have problems, resulting in frequent short circuits and There is a risk of excessive stress. Considering such increased force, the beam strength of the end plates should be increased to prevent the transformer windings from moving or rounding.

The usual thing about increasing the strength of the end plate is to increase its thickness. However, this will increase the weight of the transformer, which will be expensive to ship and difficult to handle. In addition, conventional end plates had to sharpen the sharp edges of the rectangular plane to prevent corona discharge at this point.

The trend that high voltage is required in power distribution devices also has problems with the mechanical performance of magnetic cores in electrical induction devices such as transformers. In a typical construction, the yokes or legs of the magnetic core are connected by a so-called step-lap connection, which is described in great detail in U. S. Patent Nos. 3, 153 and 215, assigned to the assignee of the present application. . In this structure the connection between the diagonally cut ends of the core lamination horns legs and yokes is progressively bent from the connection points of the adjacent layers. When the force acting on this type of magnetic core is increased due to a higher than normal operating voltage, the legs of the core are moved or separated from the yoke of the connection. Conventional support structures are insufficient to hold the entire magnetic core against high mechanical forces, i.e. limit the maximum ratings of rectangular core and coiled transformers.

In view of the above, it is desirable to provide an electrical induction device such as a transformer with a rectangular core and coil to provide an improved mechanical structure, as in the transformer structure of the present invention, to have a higher rating than was possible with conventional methods. It can be seen that.

To achieve this, it is most important to eliminate or essentially limit the movement of the magnetic core and the windings caused by short circuits or transients. It would therefore be desirable to provide an improved support structure that can increase the force limiting movement of the windings without increasing the weight of the support structure. It is also advantageous to provide a transformer with an improved support structure which prevents the legs of the magnetic core from moving against the core yoke.

It is intended here to have a new support structure that allows electrical induction devices, such as transformers, which require higher ratings than before, to have higher ratings than before. The support structure includes upper and lower yoke frames positioned near the upper and lower yokes of the magnetic core of the electric induction device, and first and second end plate assemblies adjacent the outer winding and connecting the upper and lower yoke frames. Each end plate assembly is essentially tubular in cross-section, which is strong and disease-free to increase the strength of the support structure without significant increase in mass.

The tubular end plates are disposed in conformity with each outer winding and welded to the upper and lower yoke frames of the yoke frame to form a rigid support structure. This support structure prevents the movement of the windings and provides a transformer structure using a core and coil of rectangular cross section. In this case, the rectangular winding prevents it from rounding due to the short-circuit or transient forces.

The unique support structure for the electric induction apparatus according to the present invention can increase the bearing capacity to produce a transformer having a high rating without increasing the weight, thereby reducing the shipping cost and easy operation during assembly. Instead of increasing the thickness of the rectangular plates in the conventional end plates, the bearing capacity is increased by increasing the depth of the end plates and having a box-like structure. Furthermore, the use of mechanically curved channel plates to form a box-like structure minimizes corona generation, which is located on the round convex surface facing the nearest winding.

These mechanically curved channel plates have no sharp edges that are susceptible to corona. Therefore, in the conventional structure using a simple metal plate as the end plate structure, it is necessary to round the sharp edges, but this is not necessary here.

Unique upper and lower braces are also provided to counteract the force to separate the lamination of the core legs from the junction with the core yoke. This force is very large for rectangular core and coil type transformers rated above 5 MVA. The upper core brace is positioned to be adjustable between the outer core leg on the winding and the end plate assembly.

Appropriate adjustments are made to force each upper core brace against the core leg, thereby providing a rigid connection or brace between the core leg and the end plate assembly to allow the core leg to be separated or moved from the upper yoke during operation of the electrical induction device. It prevents you from becoming.

The design of the present invention not only prevents the movement of the core legs, but also simplifies the assembly of the support structure, since welding between the core brace and the end plate assembly after the final adjustment is not performed near the windings. This is because material splashing in the city falls into the windings and causes no problems during operation of the electric induction apparatus. Furthermore, the tubular cross section of the end plate assembly allows the upper core brace to be supported against the core leg to form a rigid support structure without the need for precision devices.

The lower core brace is located below the winding adjacent to the outer core leg to allow restraining movement there. The lower core brace includes an insulator, which is positioned in conformity with the core leg and the plate adjacent to it and connected to the lower end plate in the same way as welding to provide a rigid brace so that the core leg is lower than the magnetic core. This prevents them from being removed or moved from the yoke.

With reference to the accompanying drawings illustrating the advantages and another embodiment of the present invention as follows.

3 shows a three-phase transformer 10 dried according to the present invention. Transformer 10 includes a magnetic core and a coil assembly 12, which assembly 12 is a wound winding assembly 16, 18, and 20 positioned in an inductive relationship around the magnetic core 14. ) The magnetic core 14 is made using a large number of laminations of a suitable magnetic material and includes an upper yoke portion 22, a lower yoke portion 24, and legs 26, 28, and 30. It is connected to the upper and lower yoke portions 22 and 24 to form the magnetic core 14. In a preferred embodiment of the present invention, the bridge-like end of the bridge and the yoke of the magnetic core are connected by a so-called step wrap, where the bridges of the bridge or diagonally cut ends and laminations of each layer The connection points between the yoke laminations of the bends are gradually bent by a predetermined stepwise pattern at the connection points installed in adjacent layers in a similar manner. Furthermore, the legs 26, 28 and 30 of the magnetic core 14 have an essentially rectangular cross-sectional structure.

The winding assemblies 16, 18 and 20 are arranged axially in an inductive relationship around the legs 26, 28 and 30 of the magnetic core 14, respectively. Each of the winding assemblies 16, 18, and 20 includes low and high voltage windings of plate or strip conductors to form a number of turns around each leg of the magnetic core 14. Furthermore, the winding winding assemblies 16, 18 and 20 are wound tightly in an essentially rectangular cross-section around the leg of the magnetic core 14. For simplicity, the bushings and conductors used to connect the high and low voltage windings in the winding assembly are omitted.

The core and coil assembly 12 is firmly fixed by a suitable support structure 40 formed of upper and lower yoke clamps 42 and 44 and first and second end plate assemblies 46 and 48, respectively. These yoke clamps and assemblies are tightened to provide a rigid structure that limits the movement of the windings during operation of the transformer 10. The upper and lower yoke clamps 42 and 44 each consist of two objects connected in an essentially M-shaped cross-sectional structure and are positioned in conformity with the upper and lower yokes 22 and 24 of the magnetic core 14. The components of each of the upper and lower end plates 42 and 44 are welded under pressure to form a rigid structure and act to clamp the upper and lower yokes 22 and 24 of the magnetic core 14. This sinning action not only secures the lamination of the magnetic core 14 but also has the advantage of attenuating the sound of the transformer 10. The first and second end plate assemblies 46 and 48 generally comprise the outer winding assemblies of the magnetic core and coil assembly 12, ie the wide and flat portions of the rectangular winding of the assemblies 16 and 20. And are accurately placed. The end plate assemblies are described as mating with the windings but in practice a suitable insulator, such as the insulation plate 50 of the end plate assembly 48, is disposed between the windings and each end plate assembly.

When the electric induction device such as the transformer 10 is operated, the electric induction device is subjected to a large force by a short circuit or a transient condition. In the conventional transformer, since the low voltage winding is located concentrically inside the high voltage winding, such a large force is applied to the low pressure winding inward to affect the legs of the magnetic core, and to the high voltage winding outward. easy. However, in a transformer having a rectangular core and a coil, the high-voltage winding is easily deformed from the original rectangular shape into a round shape. As the power distribution system voltage increases, the force applied to the windings due to circuit overstage and transient conditions increases, and thus, a greater strength is required for the supporting structure, especially the end plate assembly, to prevent the movement of the magnetic core and the coil. In conventional constructions in which the end plates consist of thick steel plates, this increase in strength can only be achieved by increasing the thickness of each plate. However, this results in a large increase in the total mass of the transformer, which increases shipping costs and problems in handling.

1, 2 and 3 illustrate a support structure using an improved end plate assembly capable of obtaining the required strength without significant increase in mass. The end plate assemblies 46 and 48 shown in FIG. 1 are identical, so only the end plate assembly 48 will be described later. Furthermore, in the preferred embodiment of the present invention described below, the end plates are described as being made by connecting two tubular cross-sectional structures, but the same structure as using a single square or rectangular tubular body with a hollow box portion therein. It will be emphasized that also fall within the scope of the present invention.

The end plate assembly 48 includes a plate 52 extending in the axial direction. The endplate assembly 48 also includes an axially extending channel 54, which has a U-shaped cross section. As shown more clearly in FIG. 3, the channel 54 includes ends 56 and legs 58 and 60 that are mated to the outermost turn of the winding assembly 20. One end of the leg portion is connected to the inner surface of the rectangular plate 52 by a suitable method such as welding or the like. The upper and lower portions of the channel 54 are fitted into the upper and lower end frames 42 and 44 respectively. Weld to form the support structure 40.

The structure of the plate 52 and the channel 54 of the end plate assembly 48 provides a strong and rigid support structure to prevent the winding assembly 20 from moving or rounding due to forces generated by short circuits or transient conditions. Give it. In addition, the strength of the end plate assembly 48 is further increased by a number of axially spaced ribs, such as the lips 62, 64, 66 shown in FIG.

Lips 62, 64, 66 are shown in more detail in FIG.

These are located between the plates and channels 52 and 54 of the end plate assembly 48 and fill the openings or channels therebetween. Each lip is connected to the U-shaped channel in a suitable manner such as welding to increase the bearing capacity of the channel 54. Forming an end plate assembly using multiple elements welded to each other simplifies the process by making it possible to easily obtain elements of the desired size, thus eliminating the need for anomalous polishing and furthermore the ribs can be easily inserted into the assembly.

The new end plate assemblies having the tubular or box-shaped cross-sections described above have a bending strength per unit mass that is essentially greater than that of conventional slab-shaped end plate assemblies. In conventional cases, increasing the strength requires an increase in the thickness of the end plates, so that the mass increases significantly, but this new type shows little increase in mass for the same bending strength. To increase the strength, it is only necessary to increase the depth or width of the U-shaped channel 54 legs, so that the mass of the end plate does not increase greatly or the size of the transformer increases.

Furthermore, the rounded corners between the flat portion 56 of the channel 54 of the end plate assembly 48 and the flanges 58 and 60 have a rounded and smooth surface facing the conductive element of the transformer 10. It suppresses the occurrence of corona. Conventional end plates of the slab type shall be polished with rounded sharp edges to prevent corona from occurring at these edges.

Another embodiment of the present invention is shown in FIGS. 2, 3, 4, and 5. Unique upper and lower core races 80 and 100 are installed to prevent the magnetic core 14 of the transformer 10 from moving due to a force generated by a short circuit or a transient condition.

1, 2 and 3 show the upper core brace 80 dried according to the present invention. A detailed description of the upper core brace 80 will be described later with the core leg 30, the winding assembly 20, and the end plate assembly 48 together. Note that the same upper core brace is installed on the opposite side of the transformer. The upper core brace 80 thus comprises a first plate 82, which is made of a suitable electrical insulator, such as sold under the trademark “Mikata”, and is positioned in conformity with the core leg 30 so that the upper core brace is Insulate the rest of 80 from the magnetic core 14 of the transformer. An equally shaped second plate is positioned in connection with the first plate 82, which is made of a strong material such as steel. The first and second bars 86 and 88 are provided above and below the first and second plates 82 and 84 and are connected to the second plate 84 by welding or the like, although not shown. The first and second plates 82 and 84 are fixed. Suitable connections, such as nuts and bolts 90 and 92, are also provided to secure the first and second plates 82 and 84 when assembling the core brace 80.

As shown in FIG. 2, the bar 88 is positioned below the first and second plates 82 and 84 and supported by an upper coil block 89, which is made of an insulator such as wood. To increase the brace action to prevent the movement of the winding assembly 20 during operation of the transformer.

Connecting devices such as rods 94 and 97 are provided to connect the first and second plates 82 and 84 of the upper core brace 80 to the end plate assembly 48. The rods 94 and 97 each have a number of external screws in the region adjacent the end plate assembly. The opposite ends of each of the rods 94 and 97 are not shown but are connected to the second plate 84 in a suitable manner, such as by welding. The connection also includes adjustments such as nuts 95 and 96 of the rod 94 and nuts 98 and 99 of the rod 97 which, when assembled, are assembled in the upper core brace 80. It enables adjustment to simplify the structure of the brace. The rods 94 and 97 of the upper coarse brace 80 are inserted into the end 56 of the U-shaped channel 54 of the end plate assembly 48 through holes not shown, after which the nut (on the top) 95), 96, 98, 99 are tightened and end plate assembly 48 is disposed between and welded between upper and lower end frames 42 and 44. After the upper and lower ends of the end plate assembly 48 are welded to the upper and lower end frames 42 and 44, the nuts 95, 96, 98, and 99 are rods 94 and 97, respectively. Tightened to and locked in a suitable manner such as welding. The core brace 80 is thus fixed and forms a rigid structure that prevents the core leg 30 from being separated or moved from the upper yoke portion 22 of the magnetic bore 14.

The unique core brace 80 prevents the legs from being separated or moved from the yoke portion of the magnetic core of the transformer through interaction with the end plate assembly 48. Furthermore, through the combination of the upper core brace 80 and the unique end plate assembly 48, the material splashing from the assemblies of these elements during welding falls into the core of the transformer 10 and the coil assembly 12 so that It also reduces problems such as short circuits during operation. This is because the welding to fix the core brace 80 is made between the two bodies of the end plate assembly 48 and not on the core and the coil assembly 12. In addition, the assembly of the upper core brace 80 is simplified by eliminating the need for time-consuming polishing operations and fine manipulation of manufacturing tolerances.

4, a new lower core brace 100 is shown. This is located under the outer winding assembly, such as the winding assemblies 16 and 20 of the transformer 10 to prevent the core legs from being separated or moved from the lower yoke 24 of the magnetic core 14. The same lower core braces as in the upper core brace 80 are used at the junction between the outermost leg, such as the legs 26 and 30 of the magnetic core 14 and the lower yoke portion 24 of the magnetic core 14. . However, only one core brace will be addressed for clarity. The core brace 100 includes an insulator 102 made of an electrical insulator, such as a material sold under the trademark of "Mikata, which is positioned in conformity with the lower portion of the core leg 30 of the magnetic core 14. The resulting steel body 104 is positioned adjacent to the insulator 102 and secured with a coupling device such as nuts and bolts 106, 108, etc. The upper and lower bars 110, 112 are insulated and steel 102 ( Although not shown, it is fixed to the steel body 104 by a welding method or the like, so that the lower core brace 100 is assembled (102, 104) does not move. When assembling the brace 100, the insulator 102 and the steel body 104 are fixed to each other by nuts and bolts 106 and 108 such that the upper and lower bars 110 and 112 are connected to the steel body 104. Attached to hold the elements in place, with fixtures or rods 114 and 116 It is connected to the outer surface of the steel body 104 by a suitable method such as tack welding.

Prior to placing the winding assembly 20 on the core leg 30, the completed assembly is inserted into the lower end frame 44 and moved or pressed in place. This process continues until the insulator 102 mates with the core leg 30 and the upper bar 110 contacts the lower core block 118, which provides support to the outer portion of the winding assembly 20. Do it. At this time, a suitable connection method such as welding is applied to the fixtures 114 and 116 so that the lower core brace 110 is connected to the lower end frame 144. This creates a support that prevents the lower portion of the core leg 30 from being separated or moved from the lower yoke 24 of the magnetic core 14 during operation of the transformer 10.

While obvious to those skilled in the art, the present invention relates to an electrical induction device such as an electrical transformer with an improved support structure that prevents the core and coils from moving due to a short circuit or transient forces. The support structure is equipped with a new end plate assembly, each of which has an inherently tubular cross-section, which has sufficient bending strength to prevent the windings from moving or rounding during transformer operation. Providing a support structure with increased force improves the capacity of the transformer to withstand short circuits, thus making it possible to manufacture economical transformers with higher ratings than conventional ones, in particular with rectangular cores and coils. Also, for high rated transformers, the bending strength of the end plate assembly can only be increased by increasing the depth of the tubular body. Conventionally, the thickness of the boardboard end plate had to be increased.

Thus, in this new type, there is no significant influence on the weight or overall size of the transformer. In addition, the use of the tubular end plate assembly can have rounded corners to prevent corona generation and eliminate the need for surface polishing, which has been done for conventional slab-shaped end plates.

It is evident that the new core braces located at the junction of the yoke portion and the outer leg of the transformer's magnetic core above and below the windings prevent the legs from being separated or moved from the yoke and thus prevent the deterioration of the electrical characteristics of the transformer. . The unique upper core brace allows the adjustment of the core brace when it is assembled to interact with the end plate assembly, which simplifies the structure and causes the problem of splashing material from the assembly of the core brace into the core and coil assembly during welding. Is less. This is because welding is done to assemble these elements inside the end plate assembly and not over the core and coil assemblies.

Claims (1)

Each having a leg section 26, 28, 30 having at least a rectangular cross section, each of which has a magnetic core 14 connected by upper and lower yokes 22, 24: Winding assemblies 16, 18, 20 of rectangular shape axially arranged in engagement and subjected to radial forces in operation: an upper end frame 42 positioned to clamp the upper yoke 22 of the magnetic core 14. In the electric induction device composed of a lower end frame 44 positioned to clamp the lower yoke 24 of the magnetic core 14, the end plate assemblies 46 and 48 are electrically wound assemblies 16, 18 and 20. Extending over each of the axial lengths of and supporting each assembly, the upper and lower ends of which are connected to opposing ends of the upper and lower end frames 42, 44, such that the magnetic core 14 and the electrical winding assembly 16, 18, 20 Forming a rigid support structure for the bearing, including the flange of the channel 54 Electrical induction apparatus is characterized in that one and the cross-section has the form of a tubular end plate assemblies 46 and 48, the end plate assembly got fastened on the lower end of assembly 42, 44 to resist the force of the radial banghya.