RU2221295C2 - Electromagnetic device - Google Patents

Abstract

FIELD: electrical engineering. SUBSTANCE: proposed device can be used as choke coil, transformer, inductance coil, filter component, delay line, inductive ballast, and the like at power ranging between units of volt-amperes and kilovolt-amperes. Its winding is made of electrically insulated turns of three-layer strip whose external layers are made of metal possessing both electrical conductance and magnetic permeability. Intermediate insulating layer binds both of them into single structure. Cohesion between layers resembles linkage of anchor chain. Layers are disposed along straight or broken line, including closed one, aligned with their symmetry axes. EFFECT: reduced cost, improved characteristics, simplified design, facilitated manufacture. 4 cl, 3 dwg

Description

 The invention relates to electrical engineering, in particular to bipolar or multipolar (in terms of the number of poles for internal connections and the number of poles for external connection) elements of electrical circuits with dominant inductance and (or) mutual inductance characteristics, in particular for operation in industrial frequency alternating current circuits (50-60 Hz), e.g. to chokes, transformers, inductors, filter elements, delay lines, inductive ballasts, etc.

 Recommended power range from units B • A to units kV • A.

 Such devices necessarily contain two main parts organizing the working process: electrical and magnetic circuit. The first is used to channel electric current and is usually made in the form of an electrically insulated wire, tape, strip of material with high electrical conductivity (usually copper or aluminum), and the second is used to channel magnetic flux and is usually made in the form of isolated stamped plates, tapes, strips, wires of a material with high magnetic permeability (usually low-carbon steel, technically pure iron or its alloys).

 Known inventions [1-4], in which in order to improve the working, operational and cost characteristics of the above devices, a uniform implementation of their main parts is proposed so that they can simultaneously perform both functions: electrical and magnetic circuit.

 Such devices contain windings with electrically insulated turns of a material having both electrical and magnetic conductivity, consisting of at least one section and spatially interconnected through central holes in each of them.

 However, known devices in which active materials of construction combine the functions of an electric and magnetic circuit have disadvantages.

 Thus, the designs of the inductor [1] and induction device [3] have a toroidal shape, in which a satisfactory winding density and the magnetic conductivity of the magnetic circuit depending on it can be provided only at the ring coil. At the same time, a toroidal coil wound around an annular coil, due to a significant difference in the inner and outer diameters of the latter, will inevitably have gaps between the turns on the outer surface and, as a result, a decrease in its magnetic conductivity as a magnetic circuit. In addition, the implementation of the windings of the inductor according to [1] "from a conductor with a ferromagnetic additive in the form of a homogeneous alloy" will simultaneously lead to a sharp deterioration in its electrical and magnetic conductivity, and the implementation of the windings of the induction device [3] "by a wire consisting of a ferromagnetic base coated a copper sheath with insulation, "is equivalent to creating a short-circuited coil throughout its ferromagnetic base.

 Closer analogues of the proposed electromagnetic device are a transformer [2] and an electromagnetic device [4]. They eliminated the disadvantage of devices [1] and [3] due to the implementation of windings from bimetallic strips of foil, "one of the layers of which is ferromagnetic and the other layer is made of highly conductive material." Nevertheless, the devices [2] and [4] also have insufficient functionality associated with the presence of only two spatially coupled and magnetically disconnected windings. In particular, in electromagnetic devices [4] with three and five spatially interconnected windings, only one is magnetically independent of the other two and four, respectively, which are essentially electrically unconnected sections of the second winding wound on the first, as on magnetic circuit. Accordingly, the aspect ratio X = 0.52573 D, declared in [4], characterizes only the geometric conditions for filling the inner opening of the first winding with sections of the second and does not reflect the requirements for the optimization of electromagnetic processes in the device.

 The presence of only two magnetically independent windings also significantly limits the ability to design electromagnetic devices and adapt their overall dimensions to the layout requirements.

где k=1,2,3,...n
На фиг. 1 и 2 приведены две проекции общего вида и частичного разреза предлагаемого электромагнитного устройства, в котором сцепленные между собой обмотки расположены вдоль прямой линии, совпадающей с осями их симметрии. Там же стрелками показаны направления электрических токов и магнитных потоков в обмотках при k=1. Совершенно очевидно, что все обмотки (звенья цепи) электрически и магнитно независимы друг от друга, а их количество и абсолютные геометрические размеры практически ни чем не ограничены.The proposed electromagnetic device is free from the above-mentioned disadvantages due to the fact that its windings with electrically insulated turns of a material having both electrical and magnetic conductivity, consisting of at least one section and spatially interconnected through central holes in each of them, are interlinked between like the links of the anchor chain, each of them consists of one or more concentric electrically unconnected sections with conclusions for conductive connection to each other and connection to an external electrical circuit, and for any series and adjacent windings (links), for example, k-th, k + 1st, k + 2nd, k + 3rd .. .nth ratio of the areas S _k , S _{k + 1} , S _{k + 2} , S _{k + 3} , ... S _{n of the} central holes and the average lengths L _k , L _{k + 1} , L _{k + 2} , ... L _{n of} their turns are within

where k = 1,2,3, ... n
In FIG. 1 and 2 show two projections of a general view and a partial section of the proposed electromagnetic device, in which the windings interlocked are located along a straight line coinciding with the axes of their symmetry. The arrows in the same direction show the directions of electric currents and magnetic fluxes in the windings at k = 1. It is completely obvious that all windings (chain links) are electrically and magnetically independent of each other, and their number and absolute geometric dimensions are practically unlimited.

 Technically and economically feasible restriction can be imposed only on the ratio of geometric dimensions that implement the optimal mode of electromagnetic work processes in the windings. As an optimum, first of all, a mode can be adopted in which the constancy of physical quantities that characterize the intensity of the electric and magnetic fields in the entire working volume of the windings, or rather their active material, is achieved. Typically, in technical projects, such quantities are the electric current density and magnetic field strength or magnetic induction (magnetic flux density).

As is known, the values of the density j of the electric current in the electric circuit and the intensity H of the magnetic field created by this current in the magnetic circuit are interconnected by the law of the total current
∫Hdl = ∫jds,
where dl and ds are, respectively, elements of the length of the magnetic field line and the cross-sectional area of the electric current.

If H _k and j _k are the average values of the magnetic field strength and current density in the k-th winding, then taking into account the notation of FIGS. 1 and 2
H _k + 1L _{k + 1} = (J _k S _k + J _k + 2S _k +2) K _s , (2)
where K _z - fill factor of the inner hole of the winding with the active material.

 If, in addition, the average values of the magnetic field strength H and the current density j in all windings are the same and equal to the optimal design values, then condition (1) follows from (2), which is the hallmark of the proposed electromagnetic device.

 Figure 3 shows a General view of the proposed electromagnetic device in which interconnected windings are located along a broken line, in particular, a closed line. Essentially, figure 3 shows a General view of a three-phase electromagnetic device consisting of 6 windings.

 A fundamental feature of electromagnetic devices with a uniform structural and technological design of an electric and magnetic circuit in the form of twisted windings from a material having both electric and magnetic conductivity is the need to use shuttle winding for every second of a pair of interconnected windings. In the process of shuttle winding, the winding material with the length required to complete one winding is first wound around the shuttle, and then, using the shuttle, it is wrapped around the other (other) previously made windings. In this case, the windings of the winding material slide in and out of each other inevitably and their inter-turn insulation may be damaged. The latter is the most frequent reason for the decrease in reliability, service life, as well as yield of suitable products (electromagnetic devices) due to manufacturing defects. In the proposed electromagnetic device, the noted drawback is eliminated due to the fact that the windings are made of a three-layer tape, the outer layers of which are metal, and the inner layer connecting them together is dielectric.

Sources of information
1. USSR author's certificate 344515 with priority of 07/14/70.

 2. USSR copyright certificate 630654 with priority of 05.24.77.

 3. USSR author's certificate 1345267 with priority of 02.24.86.

 4. US patent 4916425 with priority from 08.31.88.

Claims (4)

1. An electromagnetic device comprising windings with electrically insulated turns of a material having both electrical and magnetic conductivity, consisting of at least one section and spatially interconnected through central holes in each of them, characterized in that the said windings are interconnected Like the links of the anchor chain, each of them consists of one or more concentric electrically unconnected sections with conclusions for connection between themselves and connections to an external electric circuit, and for any sequentially located in the circuit and adjacent windings, for example, k-th, k + 1st, k + 2nd, k + 3rd, ....., n-th the ratio of the areas S _k , S _{k + 1} , S _{k + 2} , S _{k + 3} , ..., S _{n of the} central holes and the average lengths L _k , L _{k + 1} , L _{k + 2} , ....., L _{n of} their turns are within

where k = 1, 2, 3, ... n. 2. The electromagnetic device according to claim 1, characterized in that the windings interlocked with each other are located along a straight line coinciding with the axes of their symmetry. 3. The electromagnetic device according to claim 1, characterized in that the interconnected windings are located along a broken line, including a closed line. 4. An electromagnetic device according to any one of claims 1 to 3, characterized in that the windings are made of a three-layer tape, the outer layers of which are metal, and the inner layer connecting them together is dielectric.

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