RU2444076C1 - Transformer - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: transformer includes a short-circuited turn (4), arranged tightly with a short-circuited turn of a wire (3) along the middle line of a winding core (2), and inverters (5) for single shift of layers in turns of the winding core (2), connected into the break of these layers in that place, where the total length of turns becomes equal to the half of the total length of the winding core turns (2). The transformer may have all structures inherent in the prototype. It may replace all types of measurement and power transformers. Since dimensions of all proposed transformers are considerably lower than dimensions of standard three-phase transformers, this replacement will also provide for higher symmetry of voltage and current transformations. Compactness, best characteristics and commercial appeal of the transformer will make it possible to use it instead of power planar transformers in the electronic industry.

EFFECT: smaller dimensions of windings and the core, losses of energy in the transformer, increased stiffness of the core, higher reliability, increased range of currents and voltages, improved characteristics of the core and windings, reduced costs for manufacturing.

2 cl, 7 dwg

Description

The invention relates to electrical engineering and can be used in electromagnetic transformers.

Known inductive element (UK Patent No. 1203948, H01F 17/04, 09/03/1970) containing one or more windings covered by one or more layers of a ferromagnet forming a closed core connecting the windings. The windings and layers of the ferromagnet have gaps and, due to this, by choosing the connections of the turns of the windings and layers of the ferromagnet, it is possible to obtain chokes, transformers and other inductive elements with the necessary parameters. In the process of assembling an inductive element, both existing windings and layers of a ferromagnet are used, as well as windings, layers of a ferromagnet, insulation layers and compounds created directly by chemical, photochemical, electrochemical, thermal and vacuum deposition, etching, electrophoresis, enameling, glazing, burning metals in insulation, acoustic processing, laser processing, milling, welding, soldering, prestressing, using various protective masks and continuous and measuring element parameters. This combined technology of sequential growth on a thin substrate provides a dense and, therefore, compact design of planar (linear) inductive elements. The flat shape of the inductive element improves the heat removal from the windings and the core, but in order to reduce vortex losses and weaken the skin effect, it is recommended to carry out the windings with a wire whose vertical cross-sectional dimension is greater than the horizontal one (Tikhomirov P.M. Transformer design .: study guide for universities. - 5th ed. - M.: Energoatomizdat, 1986. - 528 p.), And a three-dimensional inductive element has better characteristics than a planar one (Samarin A. Technology and the scope of Claw Connect. - Components and Technologies, No. 12, 2006, p.136-142 ) In the manufacture of the inductive element, an extremely large number of the best technologies were used, however, the classical design of the inductive element was preserved. This does not significantly reduce its size and improve performance.

A known current to voltage converter (Sidiryakov E.V., Lyamets Yu.Ya., Kozlov V.N. RF Patent No. 1347025, G01R 19/00, 10/23/1987), containing a closed core, on which are short-circuited and measuring windings. Due to the low electrical resistance of the short-circuited winding of the converter, you can select any point on the magnetization curve of its core, including ensuring its complete demagnetization at any measured current in the external wire penetrating the converter core. However, the converter in question has large dimensions and losses in the windings, and therefore cannot be used as power transformers.

The closest technical solution is a transformer (Kazakov V.V., Nemtsev G.A. RF Patent No. 2320045, H01F 30/06, H01F 27/28, 03/20/2008), containing a core formed by vertical rods, the upper ends of which are magnetically connected through the upper yoke and the lower through the lower yoke, the ends of the rods being electrically isolated from the yoke, the primary windings covering the rods, the rods being wound in the form of rolls of enameled tape of a ferromagnetic material with high electrical conductivity, magnetic permeability and saturation induction, e.g. an example of electrolytic iron with a purity of 99.998%, and combine the function of the secondary windings or parts thereof, which can significantly reduce the size and improve the characteristics of the transformer.

The need to increase the thickness of non-magnetic electrical insulation between the rods and yokes in the manufacture of transformers with high output voltage leads to a deterioration in the characteristics of the core and the reliability of the insulation of the windings.

Due to the fact that with this design of the transformer only part of the core, namely its rods, can simultaneously perform the function of windings, a further reduction in the size of the transformer and losses in its windings and core is limited.

The reduction of losses in the winding rods from eddy currents and the skin effect is achieved by the fact that they are wound in the form of rolls with tape containing a large number of identical, calibrated in width and electrically isolated from each other thin layers made of a ferromagnet with high electrical conductivity and high negative magnetic resistivity. Moreover, the multilayer tape does not increase the distributed capacity of the winding. Since the rods at the same time perform the function of secondary windings, then in each layer of the tape which such a winding is wound, the same intrinsic EMF is induced, which eliminates the redistribution of current between the layers due to the skin effect. Therefore, transposition of conductors in such windings is not required. However, the adjacent layers of the tape at their ends are electrically connected together and form a loop covering the part of the cross section of the core located between these layers. Therefore, between the ends of these layers an EMF difference is established equal to ΔU _SL = ω · B · (l _CR2 · d _W ), where ω is the cyclic current frequency in the windings, B is the magnetic field induction in the core, l _CR2 is the tape length, d _W - the thickness of the layer, and due to the coverage of the rod section by common turns, the value of B is distributed evenly over the rod section. To compensate for the difference in the EMF of the layers in the tape, the inner turns of the winding are wound only with the lower layer of the tape, the subsequent turns with the subsequent addition of the following layers. This compensation method requires an accurate calculation of the number of different internal and subsequent turns, because the error in the compensation of the difference in the interlayer EMF will cause an increase in losses in the secondary winding. The design of the terminals of the secondary winding is also complicated, which reduces their reliability.

The transformer description does not explain how the inner ends of the winding rods are connected to the transformer outputs. The wire through which such a connection is made can, for example, pass through the end of the winding rod and be part of a current loop covering the vertical section of the winding rod. Such a new electromagnetic system is similar to a current transformer with a torn secondary winding. Therefore, the current flowing through the connecting wire can cause perpendicular magnetic saturation of the rod, repeatedly reducing its magnetic permeability in the direction of the working magnetic flux. A similar phenomenon occurs with any other arrangement of the connecting wire. This limits the load current of the transformer.

The objective of the invention is to reduce the size of the windings and core, energy loss in the transformer, increase the stiffness of the core, increase reliability, increase the range of currents and voltages, improve the characteristics of the core and windings, reduce the cost of manufacturing a transformer.

The technical result is achieved by the fact that in the transformer containing the primary windings covering the core winding, the wire connecting the inner contact of the core winding with the first output terminal of the transformer, an isolated short-circuited coil located along a closed midline inside the core winding next to the wire is additionally introduced , also forming a short-circuited coil along a closed midline, and each coil of the core winding is made in the form of thin insulated, including between fight ferromagnetic layers with high conductivity through the simultaneous extension of the coil around the entire outer surface of the cross-section of both short-circuited windings, except for the opening of the space for passage of the isolated portion of the wire inside the winding-mandrel holes and other process; core layer inverters; moreover, all the beginnings of the layers of the ferromagnet are connected together on a short-circuited line of the wire, forming the inner contact of the core winding, the extension of the turns of the core winding is interrupted when their total length, determined in the cross section of the core winding, becomes equal to half the total length of the turns of the core winding, and the ends of the layers extended before the interruption are connected to the inputs of the parallel installed inverters of the layers, the number of which is determined from the condition of maximum filling of the line on which it interrupted s capacity turns; the beginnings of the layers of coils being further expanded are connected to the outputs of the inverters of the layers; the outer ends of the layers of the last turn of the core winding are connected together in one closed line, forming the outer contact of the core winding connected to the second output terminal of the transformer.

Thus, in order to achieve the technical result of the invention, the following changes are made to the transformer: a short-circuited coil is introduced, which is located closely with a short-circuited coil of wire along the midline of the core winding; Inverters were introduced for a single permutation of the layers in the turns of the core winding, connected to the gap of these layers in the place where the total length of the turns becomes equal to half the total length of the turns of the core winding.

A sketch of the transformer in horizontal section is shown in figure 1, and in the vertical - in figure 2. Figure 3 shows a sketch of the winding core, and figure 4 is its vertical section. In Fig.5 shows a sketch of the inverter layers, Fig.6 is an electrical diagram of the inversion of the layers, and Fig.7 is a connection diagram of the inverter.

The transformer contains:

1 - primary windings,

2 - core winding,

3 - wire

4 - insulated short-circuited coil,

5 - inverters of the layers of the turns of the core winding.

The primary windings 1 cover the core winding 2. The entire core winding 2 additionally serves as the secondary windings of the transformer. Inside the core winding 2, a wire 3, an insulated short-circuited coil 4 and inverters 5 are installed in parallel for a single permutation of the layers in the turns of the core winding 2. A sketch of the inverter 5 layers is shown in figure 5, where: I, II, III, ..., n - the numbers of layers or contacts of the inverter corresponding to the numbers of inverted layers of the turns of the core winding 2. Inverters 5 are a set of electrically conductive thin-walled coaxial tubes of rectangular cross section, isolated between themselves and, for example, allowing rupture of one of their frontally th side of the perimeter, parallel to the longitudinal axis of the inverter.

Wire 3 connects the internal contact of the core winding 2 to the first output terminal of the transformer. An isolated short-circuited coil 4 is located along a closed midline l _c inside the core winding 2 next to (parallel) with a wire 3, also forming a short-circuited coil along a closed midline l _c . Around the entire outer surface of the cross-section of both short-circuited turns 3 and 4, the turns of the core winding 2 are synchronously expanded, with the exception of the space of the hole for passing the insulated part of the wire 3 inside the core winding 2 and other technological holes. Each coil of the core winding 2 is made in the form of isolated, including among themselves, and completely identical thin layers of a ferromagnet with high electrical conductivity. All the beginnings of the layers of the ferromagnet are connected together on a short-circuited line of the wire 3, forming the internal contact of the core-winding 2. Parallel installed inverters 5 are connected to the gap layers of the ferromagnet in the turns of the coil-core 2, i.e. the extension of the turns of the core winding 2 is interrupted at the point where the total length, determined in the cross section of the core winding 2, becomes equal to half the total length of the turns of the core winding 2. The ends of the layers of the ferromagnet, extended before the interruption, are connected to the inputs of the parallel installed inverters 5 layers of the core winding 2. The number of inverters 5 is determined from the condition of maximum filling of the line on which the build-up of the turns of the core winding was interrupted 2. The beginning of the layers of coils to be further expanded to the outputs of the inverters 5. The outer ends of the layers of the last turn of the core winding 2 are connected together in one closed line, forming the outer contact of the core winding 2, which is connected to the second output terminal of the transformer.

The transformer operates as follows.

When connecting an alternating voltage U _{1 of a} network with a cyclic frequency ω to the terminals of the primary winding 1 of the transformer with the number of turns N ₁ , in a closed magnetic circuit formed by the core winding 2, a magnetic flux Φ _slave = U ₁ / ωN ₁ ), proportional to turns I ₁ = i ₁ · N _{1 of the} primary winding, uniform across the cross section S _{c of} the core winding 2, due to the fact that it is covered by common turns, and inducing in the core winding 2 with the number of turns N _{2 the} voltage U ₂ = k _U ωN _{slave 2} F where k _U = (D + 2D _{ext Int)} / (3D + 3D _{ext Int),} D and D _{ext inner} - outer and inner diameters of the cross section of the core-winding 2. Since the electrically conductive sheet of the core-winding 2 in the direction of flow of the operating current is divided into two equal length segments, the same EMF difference equal to ΔU is induced between the ends of adjacent layers of each segment of the multilayer web _SL = ω · B · [l _CR2 / 2) · d _W ], where ω is the cyclic frequency of the current in the windings; In - the induction of the working magnetic field in the core winding 2; l _CR2 - the length of the blade in the direction of flow of the working current in it; d _W - the thickness of the iron of one layer. A single inversion of the arrangement of layers in the middle of a multilayer fabric of a high-conductivity ferromagnet from which the core winding 2 is rolled is provided by inverters 5. Due to a single rearrangement of the arrangement of adjacent layers of the fabric connected in series through inverters of 5 layers, the differences in the EMFs of the layers of both segments are directed opposite and their sum is zero.

In the secondary windings of transformers made of multilayer wires, consisting of insulated and completely identical thin layers, there is no effect of the skin effect on the current distribution between these layers, since the same EMF is induced in these layers, and the current is evenly distributed between the layers of the wires. Therefore, inverters of 5 layers perform only the function of equalizing the EMF of the layers. There are two completely equivalent explanations for the cause of the interlayer difference of the EMF: 1) the outer layer of the ferromagnetic winding covers a greater value of the magnetic flux than the inner layers; 2) the adjacent layers of such a winding form a closed loop covering the thread penetrating it.

The resistance R _KZ short-circuited coil 4 is significantly less than the total resistance of the connecting wires, the core winding 2 and the load of the transformer. This ensures zeroing of any magnetic flux perpendicular to the _slave , and eliminates the deterioration of the magnetic characteristics of the core winding 2 due to the load current of the transformer.

Thus, in comparison with analogues and prototype achieved the following advantages:

1) the entire core of the transformer additionally performs the functions of its secondary windings. This allows you to reduce the size of the windings and the core, and therefore, the energy loss in the transformer, proportional to these sizes;

2) due to the solid core, which does not have a jerk, all points of each turn of the core winding 2, aligned in a line parallel to the midline l _from the core winding 2, are equipotential. Therefore, the restrictions on the maximum secondary voltage U _{2 of the} transformer are removed, associated with the need to increase non-magnetic insulation between the parts of the core. As well as a simultaneous increase in the rigidity of the core structure, this significantly increases the reliability of the transformer;

3) the use of inverters 5 layers of simple design increases commercial attractiveness, because reduces the cost of manufacturing a transformer; however, a large number of layers in the turns of the core winding 2, used to increase the load current and reduce losses, improves the characteristics of the core and windings;

4) due to the neutralization by a short-circuited coil 4 of the perpendicular magnetization of the core winding 2 by the current of the connecting output wire 3 or by other currents causing this magnetization, the restrictions on the maximum current I ₂ of the transformer load are lifted.

The transformer can be made of the same materials from which the prototype is made. For example, the core winding 2 can be made of 5-50 μm layers of 99.998-99.999% electrolytic iron produced by electro-magnetic refining at the Kyshtym Copper-Electrolyte Plant, or at Industrial metal powders {India) pvt. ltd., enameled with 3 μm polyimide with a coloring filler Al ₂ O ₃ and having the following characteristics: resistivity ρ _{26 ° C} = 0.0947 μOhm · m; relative magnetic permeability µ = 100000 ... 120000; saturation induction B _max = 2.66-2.70 T; coercive force H _c <2 A / m.

The core winding 2 can be produced by butt low-temperature (80 ° C) welding of foil strips of ferromagnetic metal using the DIMET device (manufactured by the Obninsk powder spraying center) with copper or iron vapor, or from pre-stamped semi-cylindrical or rectangular parts, joining them using the DIMET device . The core winding 2 can also be made by the method of layer-by-layer growth of iron using penta-carbonyl technology and the formation of insulation by oxidation using appropriate masks.

The transformer can have all the designs inherent in the prototype, and can replace all types of measuring and power transformers. Since the dimensions of the three transformers made according to the claimed invention are significantly smaller than the dimensions of standard three-phase transformers, such a replacement will also provide an increase in the symmetry of the transformation of voltages and currents.

The compactness, best characteristics and commercial attractiveness of the transformer will make it possible to use it instead of power planar transformers in the electronics industry.

Claims (2)

1. A transformer containing primary windings covering the core winding, a wire connecting the inner contact of the core winding with the first output terminal of the transformer, characterized in that it further comprises inverters of the layers of the turns of the core winding and an isolated short-circuited coil located inside the core winding along its closed midline parallel to the wire installed along the midline of the core-winding with the possibility of forming a short-circuited coil, each coil of the winding -the core is made in the form of thin insulated, including between each other, layers of a ferromagnet with high electrical conductivity located by synchronously building up this coil around the entire outer surface of the cross section of both short-circuited turns except for the hole for passing the insulated part of the wire inside the core winding, all the beginnings of the layers of the ferromagnet are connected together on a short-circuited line of the wire with the possibility of the formation of an internal contact of the winding-core, the turns of the core winding are interrupted with a total length in the cross section of the core winding equal to half the total length of the turns of the core winding, the ends of the layers of the ferromagnet extended to interrupt are connected to the inputs of parallel installed inverters, the number of which corresponds to the condition of maximum filling of the line on which the interrupt build-up of turns, and the beginning of the layers of turns of the core winding, further expanded, are connected to the outputs of the inverters;
the outer ends of the layers of the last turn of the core winding are connected together in one closed line with the possibility of forming an external contact of the core winding connected to the second output terminal of the transformer. 2. The transformer according to claim 1, characterized in that the inverters of the layers of the turns of the core winding are made in the form of a set of electrically conductive thin-walled coaxial tubes of rectangular cross section, insulated between each other, and, for example, allowing rupture of their one front side of the perimeter parallel to the longitudinal axis of the inverter.

Images