DESC:Technical Field of the Invention

[0001] The present invention relates to an improved core structureof a three phased transformer. More specifically, the present invention relates to a method of constructing an improved core configuration of a three-phased transformer for reducing losses and maintenance costs.

Background of the Invention

[0002] The core of a transformer is generally made of thin metallic plates such as silicon steel wounded or laminated to each other to reduce eddy current losses. These plates are stacked to form plurality of layers. Typically, a stacked core is in the form of rectangular or cruciform cross-section. The core and the coil are manufactured separately and assembled at a later stage. There can be various types of constructions of a transformer depending on the number of phases, shape of core etc. For a single phase transformer there will be two limbs arranged in parallel on which winding coils are wound.

[0003] Similarly, three phase transformers have three or five limbs arranged in line and in parallel and both ends of each limb are connected to common yokes. In case of a five limb core, the three inner limbs are provided with windings while the outer limbs only serve as conductors for the magnetic flux. In case of three limb cores, all three legs are provided with windings. The core of three phase transformer can be of any shape.

[0004] One of the known configurations of the transformer core is a coiled stripped magnetic core with greater axial dimension than the width of the strip. To manufacture this core, a plurality of layers of the magnetic steel strips is simultaneously coiled to form the cylindrical core. The sum of the width of the strips in each layer is equal to the axial dimension of the core, and at least one longitudinal edge of each strip is staggered is relation to those in adjacent turns of the resultant coil.

[0005] Another known configuration of the transformer core is of using a plurality of toroids to obtain a desired height of the transformer core. To attain this structure, toroids are stacked one above the other until desired height is reached. This configuration incurs more energy losses caused by unavoidable introduction of unwanted air gaps between each two adjacent toroids.

[0006] In case of a damage of any part of the core of a three phased transformer, the entire core need to be removed from the structure and need to assemble the new one which involves high maintenance costs. This method also includes damage of the winding coils and side cores while removing the damaged core. In some cases, the complete device is need to be replaced which adds more cost.

[0007] Thus, there is a need to provide a unique configuration of a three phase transformer which improves the loss characteristics of the above mentioned designs and further providing ease of replacement of a core in case of a damage to a smaller portion of the core.

Brief Summary of the Invention

[0008] The present invention recognizes the limitations of the prior art and the need for systems and methods that are able to provide assistance to users in a manner that overcomes these limitations. The present invention which relates to an improved core structure ofa three-phase transformer.

[0009] A principal object of the present invention is to design a unique configuration of the core with splits in the form of cuts and protrusions extending in longitudinal direction at the center of the limbs joined together to form a core of a three phase transformer.

[0010] Another object of the present invention is to provide a unique arrangement of split cores of a three phase transformer in a manner such that the replacement of limbs and/or winding coils is attained easily.

[0011] According to first aspect of the present invention, an improved core structure of a three phased transformer for reducing losses and maintenance costs. The three phased transformer comprises of at leasta three core configurations, each formed from a plurality of laminated sheets, a plurality of limbs wherein at least two limbs joined together to form a core of a three phased transformer, a plurality of winding coils and a plurality of splits provided on their limbs of the core atits center.

[0012] In accordance with a first aspect of the present invention, further splits on the limbs characterizedto bein the form of cuts and extending portions in longitudinal direction in zig-zag pattern.

[0013] In accordance with a first aspect of the present invention, the transformer is characterized to configure the transformer setting symmetrical throughthe magnetic flux to reduce transformer core losses.

[0014] In accordance with a first aspect of the present invention, the winding coils are characterized to be wound separately and assembled together.

[0015] In accordance with a first aspect of the present invention, the transformer is characterized to form a neutral point at the union of at least three limbs and provide an easy replacement of the damaged core or a limb of a three-phased transformer thereby toreducemaintenance costs.

[0016] According to a second aspect of the present invention, a method of constructing an improved core structure of a three phased transformer for reducing losses and maintenance costs. The method comprises steps of forming at least three core configurations with plurality of laminated sheets and joining at least two limbs together to form a core of the three-phased transformer.

[0017] In accordance with a second aspect of the present invention, further wherein the method is to arrange the core of the three phased transformer by a quasi-rectangular frame and provides ease of replacing damaged cores or windings thereby reducing the maintenance costs. Further, a machine is used for developing laminations for cutting and bending the sheets.

Brief Description of the Drawings

[0018] Other objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments, in conjunction with the accompanying drawings, wherein like reference numerals have been used to designate like elements, and wherein

[0019] FIG. 1 illustrates a perspective view of the core transformer with cuts and protrusions at the center of the limbs according to the present invention.

[0020] FIG. 2 illustrates a perspectiveview of the core transformer with splits on the limb according to the present invention.

[0021] FIG. 3a-3cillustrates a method of arrangement of a three splitcoretransformer to form a three phase split core transformer according to the present invention.

[0022] FIG. 4 illustrates a perspective view of the three-phasetransformer according to the present invention.

[0023] FIG. 5 illustrates a top view of the three-phase transformer according to the present invention.

Detailed Description of the Invention

[0024] The present invention is directed towards a uniquearrangement of an improvedcore for a three phased transformerprovided with splits at the center of the core. Referring to the drawings, wherein like reference numerals designate identical or corresponding configurations, preferred embodiments of the present invention are described.

[0025] The use of “including”, “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. Further, the use of terms “first”, “second”, and “third”, and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another.

[0026] In accordance with an exemplary embodiment of the present invention, an improved core structure of a three phased transformer for reducing losses maintenance costs. The three phased transformer comprises of at leasta three core configurations, each formed from a plurality of laminated sheets, a plurality of limbs wherein at least two limbs joined together to form a core of a three phased transformer, a plurality of winding coilsand a plurality of splits provided theirlimbs of each core at its center.

[0027] In accordance with an exemplary embodiment of the present invention, further splits on the limbs characterized to been the form of cuts and extending portions in longitudinal direction in zig-zag pattern

[0028] In accordance with an exemplary embodiment of the present invention, the transformer is characterized to configure the transformer setting symmetrical throughthe magnetic flux to reduce transformer core losses.

[0029] In accordance with an exemplary embodiment of the present invention, the transformer is further characterized to arrange the plurality of limbs provided with splits in a manner to form of a ‘?’ configured three-phase transformer

[0030] In accordance with an exemplary embodiment of the present invention, the winding coils are characterized to be wound separately and assembled together.

[0031] In accordance with an exemplary embodiment of the present invention, the three phase transformer is characterized to form a neutral point at the union of at least three limbs and provide an easy replacement of the damaged core or a limb of a three-phased transformer thereby to reduce maintenance costs.

[0032] In accordance with an exemplary embodiment of the present invention, a method of constructing an improved core structure of a three phased transformer for reducing losses and maintenance costs. The method comprises steps of forming at least three core configurations with plurality of laminated sheets and joining at least two limbs together to form a core of the three-phase transformer.

[0033] In accordance with an exemplary embodiment of the present invention, the method further comprises steps of providing a plurality of winding coils, forming a plurality of splits in the form of cuts and protrusions extending in longitudinal direction at center of the limbs, arranging at least three limbs of a three phase transformer in a manner to form a ‘?’ configuration and winding the coils on each limb of the three-phased transformer.

[0034] In accordance with an exemplary embodiment of the present invention, further wherein the method is to arrange the core of the three phased transformer by a quasi-rectangular frame and provide ease of replacing damaged cores or windings thereby reducing the maintenance costs.Further, a machine is used for developing laminations for cutting and bending the sheets.

[0035] Referring to drawings, illustrates various embodiments of arrangement of an improved core of a three-phasedtransformer with splits at the center of the limbs of the core forease ofreplacing the limbs in case of damage is described.

[0036] FIG. 1 illustrates a perspective view of a core100 of a three-phase transformer according to the present invention. The core 100 of a transformer comprises of two limbs on its sides having an upper portion 102 and a lower portion 112. Splits 108are provided at the center of each limb of the core 100 separating the upper portion 102 and lower portion 112 of the limbs ofa core 100 of a three phased transformer. The splits 108are in the form of cuts and protrusions extending in longitudinal direction at the center of the limb portions 102 and 112with sharp edges 110 are provided in order to replace the damaged core of a transformer at reduced maintenance costs.

[0037] The upper portion 102 and the lower portion 112 of the limbs are joined together to form a core as shown in the FIG. 2. The core 200 made from two limbs with an upper portion 202 and a lower portion 212 provided with splits 208 in the form of cuts and protrusions extending in longitudinal direction at the center of the limbs arranged together to form a core of a three phase transformer. Any portion of the limb of the transformer can be easily replaced by providing splits with reduced maintenance costs.

[0038] FIG. 3a-3c illustrates a method of arrangement of three split cores of a three-phase transformers 300a, 300b, 300c with limbs having an upper portion 302a, 304a, 306a, 302b, 304b,306b, 302c, 304c, 306c and the lower portion of the limb 312a, 314a, 316a, 312b, 314b, 316b, 312c, 314c, 316c are provided with splits 308a, 308b, 308c at the center of each limb of the core respectively. FIG. 3a illustrates two separate half’s of the cores i.e. a limb of a core with upper portion and lower portion are provided with splits at its center of one limb of each core. FIG. 3b illustrates the arrangement of two separate limb of the core arrangedto form a split core transformer. FIG. 3c illustrates the arrangement of three limbs provided with splits at its center as shown in FIG. 2 to form a ‘?’ configured or delta configured three-phase transformer with a neutral point 330c at the union of three limbs.

[0039] FIG. 4 illustrates a perspective view of the three-phase transformer 400 constructed using three limbs each having two portions i.e. upper portion of the limb 402, 404, 406 and the lower portion of the limb 412, 416, 414 (not shown). Winding coils422, 424, 426 are wound on each limb of a three phase transformer providing a neutral point 430 at the union of the three limbs forming a ‘?’ or delta configured three phase transformer.

[0040] FIG. 5 illustrates a top view of the three phased transformer 500 with three limbs 532, 534, 536 with winding coils 522, 524, 526 wounded on each limb of the transformer with a neutral point 530 at the union of these three limbs to form a ‘?’ configured three phase transformer.

[0041] The present invention is not limited to the embodiments as shown in the drawings for the split core transformer and the arrangement of the three phased split core transformer. Additional benefits and advantages of the present embodiments will become apparent in those skilled in the art to which the embodiments relate from the description of the preferred embodiment and the appended claims, taken in conjunction with the accompanying drawings. It is important, therefore, that the claims be regarded as including such design and methods in so far as they do not depart from the spirit and scope of the embodiments described herein.

[0042] The present invention may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
,CLAIMS:I/We claim
1. An improved core structure of a three phased transformer for reducing losses and maintenance costs, wherein the three phase transformer comprises of:
at least three core configurations, each formed from a plurality of laminated sheets;
a plurality of limbs, wherein at least two limbs joined together to form a core of a three phased transformer;
a plurality of winding coils; and
a plurality of splits provided on their limbs of the core at its center.

2. The splits on the limbs according to claim 1, characterized to be in the form of cuts and extending portions in longitudinal direction in zig-zag pattern.

3. The transformer according to claim 1, characterized to configure the transformer setting symmetrically through the magnetic flux to reduce transformer core losses.

4. The transformer according to claim 1, characterized to arrange the plurality of limbs provided with splits in a manner to form a ‘?’ configured three-phase transformer.

5. The winding coils according to claim 1, characterized to be wound separately and assembled together.

6. The transformer according to claim 5, characterized to form a neutral point at the union of at least three limbs of the three-phase transformer.

7. The transformer according to claim 1, characterized to provide easy replacement of the damaged core or a limb of a three-phased transformer thereby to reduce maintenance costs.

8. A method of constructing an improved core structure of a three phased transformer for reducing losses and maintenance costs, wherein the three phase transformer comprises steps of:
forming at least three, core configurations with plurality of laminated sheets;
joining at least two limbs together to form a core of the three-phased transformer;
providing a plurality of winding coils;
forming a plurality of splits in the form of cuts and protrusions extending in longitudinal direction at center of the limbs;
arranging at least three limbs in a ‘?’ configuration; and
winding the coils on each limb of the three-phased transformer.

9. The method according to claim 8, wherein arranging the core of the three phased transformer by a quasi-rectangular frame.

10. The method according to claim 8, wherein provides ease of replacing damaged cores or windings thereby reducing maintenance costs.

11. The method according to claim 8, wherein uses a machine for developing laminations for cutting and bending the sheets of the core.