RU181871U1 - MULTI-PHASE TRANSFORMER - Google Patents

Abstract

The inventive utility model relates to transformer construction and can be used in multiphase semiconductor converters of electrical energy. The technical result consists in expanding the arsenal of multiphase transformers. The technical result is achieved in that in a multiphase transformer with a magnetic circuit made of four identical twisted rings 1-4 polished on one side and rectangular burnt teeth polished at the ends 5 and assembled so that two rings 2 and 3 glued together by unpolished sides, form the middle part of the magnetic circuit, and the other two rings 1 and 4, facing the polished sides to the middle part of the magnetic circuit, form its side parts adjacent to the middle part through equidistant with respect to the axis of sym etriy rings and relative to each other around the circumference of the teeth 5, glued by polished ends to the middle and side parts of the magnetic circuit and forming grooves 6 with them for laying coils of the three-phase primary 7 and multiphase secondary 8 windings covering the middle part of the magnetic circuit, isolated from the rings of the middle part and teeth the magnetic core with a groove insulation 9 of dielectric material, according to a utility model, the groove insulation is formed by two identical mirrored from both ends of the middle part of the magnetic core cast cast parts 10 and 11 made of a dielectric material in the form of a straight circular hollow cylinder 12, in the wall of which there is an annular recess 13 from one end, the width and depth of which is equal to the width and height of one of the rings of the middle part of the magnetic circuit, and from the opposite end the walls of the specified cylinder are radially mutually equidistant hollow rectangular parallelepipeds 14 according to the number of teeth adjacent to one of the ends of the middle part of the magnetic circuit, the width, depth and length of the through internal tversty 15 which are respectively the width, height and length of the teeth; moreover, all the walls of the cast parts of the groove insulation have the same thickness necessary to ensure insulation of the conductors of the three-phase primary and multiphase secondary windings relative to the magnetic circuit. 6 ill.

Description

Application area.

The inventive utility model relates to transformer construction and can be used in multiphase semiconductor converters of electrical energy.

The level of technology.

A multiphase transformer is known in which twisted teeth are glued with ferromagnetic glue onto both end surfaces of the middle twisted annular magnetic circuit, and sections of the three-phase primary and multiphase secondary windings are laid in grooves formed by the teeth and end surfaces of the middle magnetic circuit (see RF patent, 2187163, N 01 F 30/14, 2002) [1].

To reduce the resistance of the magnetic circuit at the junction of the teeth to the middle magnetic circuit, their respective end surfaces are ground. In this case, the air gaps between the teeth and the middle magnetic circuit are reduced, which affects the efficiency of the transformer in the direction of its increase due to a decrease in the no-load current.

However, after polishing both end surfaces of the middle magnetic circuit, the ends of the tape of electrical steel from which it is wound turn out to be wrinkled, which causes them to short circuit with each other and affects the efficiency of the transformer in the direction of its reduction due to an increase in eddy current losses in this magnetic circuit.

In a transformer with twisted teeth, as well as in a transformer with milled teeth, the magnetic flux in the teeth is also perpendicular to the direction of rolling of the electrical steel tape, which determines the increase in the cross section, and hence the mass of the teeth.

In addition, the fastening of the teeth to the end surfaces of the middle magnetic circuit only using ferromagnetic glue does not provide sufficient mechanical strength of the resulting compound. As a result of this, as practice shows, when laying sections of the primary and secondary windings, the teeth often come off and the transformer assembly is suspended. The sections of the windings, which are laid in the grooves formed by the torn teeth, are removed, the surface of the middle magnetic circuit at the place of gluing and the torn teeth is cleaned and glued again. Because of this, the technology becomes more complicated and the complexity of manufacturing the transformer increases, and, consequently, the cost of its production increases.

An additional complication of the technology takes place due to the fact that in the manufacture of the transformer, twisted rings of different heights are used as the middle and side magnetic cores.

Known multiphase transformer according to the patent for invention No. 226151 [2], which solves the problem of increasing efficiency, reducing weight and simplifying the manufacturing technology of a multiphase transformer.

To this end, the middle twisted magnetic circuit is made in the form of two rings of equal height glued together on the end-ground surfaces of the unpolished surfaces, and the three-phase primary and multiphase secondary windings are laid in grooves formed by rectangular teeth glued to the external polished end surfaces of the rings of the middle magnetic circuit and welded to them along external and internal forming rings, and the teeth are made of burnt from sheets of cold-rolled electrical steel, oriented so that the direction of their rolling coincides is the direction of the magnetic flux.

The manufacture of the middle magnetic circuit in the form of two glued rings, polished on one side only, provides a break in the circuits along which eddy currents are closed in this magnetic circuit, which allows one to significantly (up to 25%) reduce the eddy current loss in it and thereby increase the efficiency transformer.

In this case, the lapping of the teeth from sheets of cold-rolled electrical steel, which are oriented so that the rolling direction coincides with the direction of the magnetic flux flowing through them, as well as the rectangular shape of the teeth, can significantly reduce their mass (by about 30-40%) and, therefore, the mass transformer as a whole. Moreover, due to the rectangular shape of the teeth, an increase in the cross-sectional area of the grooves is provided, which contributes to better cooling of the transformer core during its operation, that is, an increase in its load capacity.

Since in the proposed transformer the teeth are welded to the rings of the middle magnetic circuit along their external and internal generators, the possibility of separation of the teeth from the magnetic circuit when laying the windings is excluded and, therefore, the technology is significantly simplified and the laboriousness of the transformer assembly is reduced. The simplification of technology is also facilitated by the manufacture of side and middle magnetic circuits from twisted rings of equal height.

However, as practice has shown, welding the teeth to the rings of the middle part of the magnetic circuit leads to the formation of short-circuited circuits in them, which cause an increase in eddy currents, and, therefore, the open circuit current of the transformer and, as a consequence, a decrease in its efficiency.

In addition, the well-known transformer uses insulation made of electrical cardboard in the form of separate fragments (elements) for each groove and tooth separately, which makes it difficult to manufacture and fix it on the teeth and in the grooves of the middle magnetic circuit and complicates the manufacturing technology, increasing time and cost of manufacturing a multiphase transformer as a whole.

The multiphase transformer according to the patent for the invention No. 2246151 for the set of essential features is selected as the closest analogue.

The technical problem solved by the claimed utility model is to simplify the manufacturing technology of a multiphase transformer. reduction of labor costs for manufacturing a multiphase transformer

The technical result consists in expanding the arsenal of multiphase transformers.

Disclosure of a utility model.

The technical result is achieved in that in a multiphase transformer with a magnetic circuit made of four identical twisted rings 1-4 polished on one side and rectangular burnt teeth polished at the ends 5 and assembled so that two rings 2 and 3 glued together by unpolished sides, form the middle part of the magnetic circuit, and the other two rings 1 and 4, facing the polished sides to the middle part of the magnetic circuit, form its side parts adjacent to the middle part through equidistant with respect to the axis etriy rings and relative to each other around the circumference of the teeth 5, glued with polished ends to the middle and side parts of the magnetic circuit and forming grooves 6 with them for laying coils of the three-phase primary 7 and multiphase secondary 8 windings covering the middle part of the magnetic circuit, isolated from the rings of the middle part and teeth the magnetic core with a groove insulation 9 of dielectric material, according to a utility model, the groove insulation is formed by two mirrored ones located on both ends of the middle part of the magnetic core. cast cast parts 10 and 11 made of a dielectric material in the form of a straight circular hollow cylinder 12, in the wall of which there is an annular recess 13 from one end, the width and depth of which is equal to the width and height of one of the rings of the middle part of the magnetic circuit, and from the opposite end the walls of the specified cylinder are radially mutually equidistant hollow rectangular parallelepipeds 14 according to the number of teeth adjacent to one of the ends of the middle part of the magnetic circuit, the width, depth and length of the through internal holes 15 which are respectively the width, height and length of the teeth; moreover, all the walls of the cast parts of the groove insulation have the same thickness necessary to ensure insulation of the conductors of the three-phase primary and multiphase secondary windings relative to the magnetic circuit.

Enumeration of figures.

FIG. 1 - Multiphase transformer, a section along BB in FIG. 2.

FIG. 2 - Multiphase transformer - top view, section along aa in figure 1.

FIG. 3 - Installation diagram of parts 10, 11 of the groove insulation on the middle part (rings 2 and 3) of the magnetic circuit.

FIG. 4 - Cast part of the groove insulation - top view.

FIG. 5 - Cast part of the groove insulation - bottom view.

FIG. 6 - Cast part of the groove insulation - general view.

The list of positions.

1.4 - twisted polished on one side of the ring, forming the side parts of the magnetic circuit;

2,3 - twisted rings polished on one side, forming the middle part of the magnetic circuit;

5 - rectangular lined teeth;

6 - grooves;

7 - a coil of a three-phase primary winding;

8 - multiphase secondary coil;

9 - groove insulation;

10.11 - the first and second cast parts of the groove insulation;

12 - cylindrical part of the groove insulation;

13 - the recess of the annular shape in the cylindrical part of the groove insulation;

14 - rectangular parallelepipeds of groove insulation;

15 - through the internal holes in the rectangular parallelepipeds of the groove insulation.

Implementation of a utility model.

The multiphase transformer contains a magnetic circuit made of four identical twisted rings 1-4 polished on one side and rectangular teeth polished on the ends of the teeth 5. Two rings 2 and 3 are glued together by unpolished sides and form the middle part of the magnetic circuit. The other two rings 1 and 4, facing the polished sides to the middle part of the magnetic circuit, form its side parts adjacent to the middle part through teeth equally spaced relative to the axis of symmetry of the rings 5. The axis of symmetry of the teeth 5 (Fig. 2) are located relative to the center of the middle magnetic circuit at an angle b, determined by the formula

b = p / m

where m is the number of phases of the secondary winding of the transformer.

The teeth 5 are made of baked sheets of cold rolled electrical steel, oriented so that the direction of their rolling coincides with the direction of the magnetic flux.

The teeth 5 glued by polished ends to the middle and side parts of the magnetic circuit together form grooves 6 for laying coils of the three-phase primary 7 and multiphase secondary 8 windings covering the middle part of the magnetic circuit, isolated from the rings 2,3 of the middle part and the teeth 5 of the magnetic circuit by groove insulation 9 of dielectric material (Fig.1,2).

The groove insulation 9 is formed by two identical cast parts 10 and 11 (figure 3) arranged mirror-like from both ends of the middle part of the magnetic circuit, made of dielectric material, for example, ABC plastic.

The slot insulation device is shown in FIG. 4,5,6 on the example of part 10. Each part 10,11 of the groove insulation is made in the form of a straight circular hollow cylinder 12, from one end of which there is a recess of the annular shape 13, the width and depth of which is equal to the width and height of one of the rings of the middle part of the magnetic circuit . From the opposite end of the cylinder 12, there are radially mutually equidistant hollow rectangular parallelepipeds 14 in the number of teeth 5 adjacent to one of the ends of the middle part of the magnetic circuit (Figs. 4, 5, 6). The width, depth and length of the through inner holes 15 of the parallelepipeds 14 are respectively equal to the width, height and length of the teeth 5. All the walls of the cast parts 10,11 groove insulation 9 have the same thickness necessary to insulate the conductors of the three-phase primary 7 and multiphase secondary 8 windings relative to the magnetic circuit .

Assembly of a multiphase transformer.

First, the middle part of the magnetic circuit is assembled by gluing rings 2 and 3 together with unpolished sides. Then, cast parts 10,11 of the groove insulation 9 are mounted symmetrically with respect to each other on the end surfaces of the middle magnetic circuit and fastened with adhesive heat-resistant tape. Next, ferromagnetic glue is applied to one of the polished ends of the teeth 5 and with this end the teeth 5 are inserted into the inner holes 15 of the parallelepipeds 14.

In the grooves 6 between adjacent parallelepipeds 14 lay sections of a three-phase primary and m-phase secondary windings with coverage of the middle part of the magnetic circuit.

On two opposite sides, two lateral ring twisted magnetic circuits 1 and 4 are glued to the teeth glued to the ends of the middle magnetic circuit.

In contrast to the prototype, where groove insulation is used, made of electrical cardboard in the form of separate fragments (elements) for each groove and tooth separately, which fit into the grooves and are located on the teeth after these teeth are glued to the end surfaces of the middle part of the magnetic circuit and welded to the rings of the middle part of the magnetic circuit along their outer and inner generators, in the proposed design, the groove insulation is made in the form of two cast parts, in the inner holes parallel the elec- trons of which are rigidly fixed without welding, the teeth glued to one of the polished end surfaces to the polished end surfaces of the rings of the middle part of the magnetic circuit, which eliminates their separation when laying the coils of the primary and secondary windings, simplifies the technology and, therefore, reduces the complexity of the transformer assembly.

Work.

Multiphase transformer operates as follows. When a three-phase primary winding is connected to the supply network, a rotating magnetic field is created in the middle part of the transformer magnetic circuit, which induces an m-phase EMF system in the multiphase secondary winding. In this case, the EMF of any two adjacent secondary windings is phase shifted by an angle of 2p / m. As a result, a three-phase primary voltage system is converted into an m-phase secondary system. In this case, the groove insulation of the conductors of the three-phase primary and multiphase secondary windings relative to the magnetic circuit, made in the form of two identical cast parts, ensures reliable operation of the transformer.

Industrial applicability

 The inventive multiphase transformer is implemented from industrially produced materials, can be assembled at a machine-building enterprise and will be widely used in multiphase semiconductor converters of electrical energy.

Information sources.

1. Patent No. 2187163. MULTI-PHASE TRANSFORMER. Published: August 10, 2002.

2. Patent No. 2246151. MULTI-PHASE TRANSFORMER. Published: 02/10/2005 - the closest analogue.

Claims (1)

A multiphase transformer with a magnetic circuit made of four identical twisted rings polished on one side and rectangular burnt, polished at the ends of the teeth, and assembled so that two rings glued together with unpolished sides form the middle part of the magnetic circuit, and the other two rings facing polished sides to the middle part of the magnetic circuit, form its lateral parts adjacent to the middle part through equidistant to the axis of symmetry of the rings and relative to each other around the circumference of the tooth cores glued by polished ends to the middle and side parts of the magnetic circuit and forming grooves with them for laying the coils of the three-phase primary and multiphase secondary windings covering the middle part of the magnetic circuit, isolated from the rings of the middle part and the cores of the magnetic circuit by groove insulation of dielectric material, characterized in that the groove the insulation is formed by two identical cast parts made of dielectric material located at both ends of the middle part of the magnetic circuit, mirrored In the form of a straight circular hollow cylinder, in the wall of which there is an annular recess from one end, the width and depth of which is equal to the width and height of one of the rings of the middle part of the magnetic circuit, and from the opposite end of the wall of the specified cylinder there are radially mutually equidistant hollow rectangular parallelepipeds in number teeth adjacent to one of the ends of the middle part of the magnetic circuit, the width, depth and length of the through inner holes of which are respectively equal to the width, height and length of the teeth; moreover, all the walls of the cast parts of the groove insulation have the same thickness necessary to ensure insulation of the conductors of the three-phase primary and multiphase secondary windings relative to the magnetic circuit.

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