JP2001524748A - Electromagnetic device - Google Patents

Abstract

(57) Abstract: An electromagnetic device includes at least one magnetic circuit (1) and at least one electric circuit (2, 3) including at least one winding (4, 5). The magnetic circuit and the electric circuit are inductively connected to each other. This device includes a controller (7) for controlling the operation of the device itself. The controller is configured to control the frequency, amplitude and / or phase associated with power exchanged with the device by a controller including means (9) for controlling magnetic flux in the magnetic circuit. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to an electromagnetic circuit including at least one magnetic circuit and at least one electric circuit including at least one winding, wherein the magnetic circuit and the electric circuit are inductively connected to each other, and the device is a device. It includes a control device that controls its own operation.

[0002] The electromagnetic device can be used for any electrotechnical connection. The power range is from VA to 1000 MVA. Applications at high voltages up to the maximum transmission voltage used today are primarily intended.

[0003] According to a first aspect of the present invention, a rotary electric machine is contemplated. Such electric machines include synchronous machines mainly used as generators which are connected to a power grid and a power grid, generally referred to below as a power grid. The synchronous machine may also be used as a motor or for phase adjustment and voltage control, but in this case as a mechanically idle machine. The art also includes doubly-fed machines, asynchronous converter cascades, external pole machines, synchronous flux machines and asynchronous machines.

According to another aspect of the invention, the electromagnetic device is formed by a power transformer or a reactor. Transformers are used for any transmission and distribution of electrical energy, the task of which is to allow the exchange of electrical energy between two or more electrical systems, and Electromagnetic induction is used in a known manner. The transformers primarily intended in the present invention are 3-4 kV to 400 kV-8
A few hundred kVA to 100 at rated voltage up to a very high transmission voltage of 00 kV or more
It belongs to a so-called power transformer having a rated power value exceeding 0 MVA.

[0005] Although the description of the prior art described below with reference to the second aspect above mainly describes a power transformer, the present invention is also applicable to both single-phase and three-phase reactors. is there. With regard to insulation and cooling, there are in principle the same embodiments as for transformers. Therefore, air-insulated and oil-insulated reactors and self-cooled and pressurized oil-cooled reactors are available. Although the reactor has one winding (per phase) and can be designed both with and without a magnetic core, the description of the background art is made in a wide range related to reactors.

[0006] The at least one winding of the electrical circuit is an air wound in some embodiments, but is in principle laminated normal or directional sheets or other, for example amorphous, Or a magnetic core consisting of a powder-based material or some other action suitable for the purpose of allowing alternating flux or windings. This circuit often includes one type of cooling system or the like. In the case of a rotating electric machine, this winding may be arranged in the stator or the rotor or both of the machine.

A problem with known embodiments of electromagnetic devices having the above properties is that they are relatively difficult to effectively control within a range of parameters or that the controller is relatively expensive. It is. In this regard, it has been pointed out that it is well known in generator technology to control operating parameters by field windings.
If the rotor has electromagnets, this field winding is attached to the rotor, but this has the disadvantage that it results in a more expensive and less controllable embodiment. In the case of the permanent magnet type rotor, there is a problem that the field control is practically impossible. Of course, this makes control more difficult in general control, especially in sensitive control situations. A further problem with the prior art is that with conventional winding techniques, winding acquisition is expensive. Known embodiments also cause significant energy losses and have limitations as far as where the windings are placed in the magnetic circuit.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is a method for simplifying and improving the controllability of an electromagnetic device according to claim 1, as well as improving the conditions for a reasonable winding production and installation. It is to devise.

A basic object of the invention is to provide a control device for controlling the frequency, amplitude and / or phase of the power exchanged with a device by a control device including means for controlling the magnetic flux in a magnetic circuit. Achieved.

Accordingly, the present invention is based on the idea of controlling the operation of the device by directly controlling the magnetic flux in the magnetic circuit as desired by controlling the magnetic flux. This makes the embodiment very reasonable and cost-effective,
Moreover, the possibility of controlling the operation to be optimized is increased.

According to one particular preferred embodiment of the invention, the control means comprises at least one control winding inductively connected to the magnetic circuit. Therefore, the control device controls the magnetic flux in the magnetic circuit as required by applying control parameters that influence the magnetic flux in the magnetic circuit within a necessary range by the control winding. Is possible. This control winding may be short-circuited. In this case, the magnetic flux may not pass through the control winding in certain embodiments.
Depending on the design of the magnetic circuit, the magnetic flux may be partially or totally interrupted.

Examples of control functions achieved by the solution according to the invention include voltage changes and voltage stabilization, transient elimination, damping of oscillations in power networks, harmonic filtering, frequency adjustment, phase adjustment ( In case the phases are controlled separately). The control device according to the invention can be adapted to add magnetic flux to the magnetic flux in the magnetic circuit,
That is, it is pointed out that the control device can operate directly from the energy source.

The control according to the invention for the magnetic flux in a magnetic circuit is, for example, in a transformer:
The secondary winding voltage can be better controlled, which means that the requirements imposed can be met, albeit with annoying fluctuations in the primary voltage, ie the load connected to the secondary winding.

Further details and advantages of the magnetic flux control according to the invention in a magnetic circuit will be clear from the following detailed description.

At least one or at least a portion of the windings of the electromagnetic device is capable of substantially sealing an electric field having magnetic permeability but generated around a conductor. It is within the scope of the present invention to include at least one flexible electrical conductor having a casing. In other words, this means that the flexible conductor and its casing (in the form of an insulator system) are formed of a flexible cable. This has considerable advantages in terms of manufacturing and mounting as compared to prefabricated shaped rigid windings that have been used to date. In addition, the insulator system according to the present invention eliminates gas and liquid insulating materials.

Since the electric field generated around the conductors in the cable in the present invention is substantially sealed in the insulation system, the generated losses are reduced by the present invention, and thus the device operates with higher efficiency I can do it. Also, such a reduction in losses reduces the temperature in the device, which in turn reduces the need for cooling, making the design of a possible cooling device simpler than without this aspect of the invention. Becomes possible.

In connection with this aspect of the invention as a rotary machine, it is thus possible to operate the machine at such a high voltage that a conventional step-up transformer can be omitted. That is, the machine can be operated at considerably higher voltages than machines according to the state of the art and can be connected directly to the power supply network. This means that the investment costs of systems with rotating electrical machines are significantly reduced and the efficiency of the overall system can be increased. Although the present invention eliminates the need for specific field control measures in certain areas of the winding, such field control measures were necessary in the prior art. A further advantage is that the present invention simplifies under-magnetization and over-magnetization, thereby reducing the reactive effects of voltage and current phase shift with respect to each other.

With regard to the embodiment according to the invention as a power network / reactor, the invention eliminates, inter alia, the need to fill the power transformer with oil and the problems and disadvantages associated therewith.

An insulator formed of a solid insulating material, at least along a portion of its entire length, and an inner layer inside and outside the insulator both made of semiconductor material By designing the winding to include an outer layer at
It is possible to seal the electric field throughout the device within the winding. As used herein, the term "solid insulating material" means that the windings lack a liquid or gaseous insulator, for example in the form of oil. In practice, this insulator is intended to be formed of a polymer material. Further, the inner layer and the outer layer are made of a polymer material, although they are semiconductive.

[0020] The inner layer and the solid insulator are rigidly connected to each other over substantially its entire boundary. Also, the outer layer and the solid insulator are rigidly connected to each other over substantially the entire boundary. The inner layer, due to its semiconducting properties, has an equalizing effect in terms of potential and thus also an electric field outside the inner layer. The outer layer is also intended to be made of a semiconductor material, so that at least its conductivity is higher than that of the insulator, so that the outer layer is connected to ground or other relatively low potential Has an equalizing effect in terms of electric potential, and thereby has a function of substantially sealing an electric field caused by the conductor inside the outer layer. On the other hand, the outer layer should have sufficient resistivity to minimize electrical losses in said outer layer.

The rigid interconnect between the insulating material and the inner and outer semiconductor layers should be uniform over substantially the entire boundary so that cavities, holes, and the like are not created. Because the present invention anticipates quite high levels of voltage, potential electrical and thermal loads can cause very large damage to the insulating material. It is well known that so-called partial discharge (PD) is generally a serious problem for insulating materials in high voltage installations. When cavities, holes or the like are created, internal corona discharges occur at high voltages, which can cause the insulating material to gradually degrade, resulting in dielectric breakdown in the insulator. This can cause severe dielectric breakdown of the electromagnetic device. Therefore, the insulator should be homogeneous.

The conductivity of the inner layer inside the insulator should be lower than the conductivity of the conductor, but at the same time it has an equalizing effect in terms of potential, and therefore equalizes to an electric field outside the inner layer. Should be at a level sufficient to have an effect. This, coupled with a rigid interconnect substantially throughout the interface of the inner layer and its insulator, i.e., the absence of cavities, etc., causes the electric field outside the inner layer to be substantially uniform, thus P
It means that the danger of D is minimal.

Preferably, the inner layer and the solid insulator are formed of a material having substantially equal coefficients of thermal expansion. The same is true for the outer layer and the solid insulator. This is because the inner and outer layers and the solid insulator expand and expand evenly as the temperature changes.
Shrinking means that such a temperature change forms the insulator system as a monolithic component without any destruction or decay at the boundary. In this way, the intimacy of the contact surface between the inner and outer layers and the solid insulator is assured, and conditions are maintained for maintaining this intimacy over a long operating period. Its bondability is such that at least the bond between the inner layer and the solid insulator, and preferably also the bond between the outer layer and the solid insulator, is ensured in conjunction with the bending that the conductor and insulator system undergo. Should be. It is pointed out here that the cable should be bendable or flexible with a radius of curvature of 25 times its diameter, preferably 15 times, so that threading of the windings is feasible. Most preferably, the cable is flexible to a radius of curvature less than eight times its diameter or substantially similar to this value.

It is important that the insulator system be made of a material having good elasticity. The E modulus of the material should be relatively low, ie, the resistance to deformation of the material should be relatively low. The electrical (E-modulus) of the layers included in the insulator system must be substantially equal to avoid troublesome shear tensions occurring at the boundary areas between the different layers included in the insulator system. Is desirable.

The electrical load on the insulator system is such that the inner and outer layers of semiconductor material tend to form a substantially equipotential surface around the insulator so that the electric field in the insulator is properly insulated. It is reduced as a result of being distributed relatively evenly throughout the body thickness.

It is well known that, for power transmission cables for high voltage and electric energy transmission, conductors are originally designed from a solid insulating material having an inner layer and an outer layer made of a semiconductor material.
For the transfer of electrical energy, it has long been recognized that insulators should not be defective. However, in high voltage transmission cables, the potential is constant over the entire length of the cable and is at the same level. However, even in a high-voltage cable for the purpose of power transmission, an instantaneous potential difference may occur due to a transient product such as lightning. According to the invention, the flexible cable according to the claims is used as a winding in an electromagnetic device.

It is further improved if the conductors in the windings are made up of smaller, so-called strands which are at least partially insulated from one another. By making the cross-sectional area of such a wire relatively small, preferably substantially circular, the magnetic field traversing the wire shows a constant shape with respect to the field and minimizes the generation of eddy currents.

According to the invention, the windings are therefore preferably made in the form of a cable comprising a conductor and an insulation system having an inner layer extending around the aforementioned strand of this conductor. Outside the internal semiconductor layer is a main insulator in the form of a solid insulator material.

The external semiconductor layer according to the invention should exhibit electrical properties such that the potential is equalized along the conductor. However, the outer layer does not exhibit conductive properties such that an induced current flows along the surface, which results in losses, which also result in undesirable heat losses. In the case of the inner layer and the outer layer, the resistance values (at 20 ° C.) in Claims 22 and 23 are effective. For the inner semiconductor layer, the conductivity of the inner layer must be sufficient to equalize the electric field potential, but at the same time, this layer must have sufficient resistivity to ensure that the electric field is sealed. Must.

It is important that the inner layer equalizes the irregularities on the conductor surface to form a surface on TEPCO with a high surface finish at the boundary with the solid insulator. The thickness of the inner layer may vary, but a uniform surface must be ensured for the conductor and the solid insulator, with a suitable thickness of 0.5-1 mm.

Such a flexible wound cable used in the electromagnetic device according to the invention may be an XLPE (cross-linked polyethylene) cable or an EP (ethylene propylene)
Is an improved rubber insulator. This improvement includes new designs, both in terms of conductor strands and, in at least some embodiments, the cable does not have an outer casing to protect itself mechanically. I have. However, according to the present invention, it is possible to arrange the conductive metal shield and the external mantle outside the external semiconductor layer. In this way, the metal shield has, for example, the property of an external mechanical / electrical protection against lightning. Preferably, the internal semiconductor layer is above the potential of the conductor. For this purpose, at least one of the conductor strands is not insulated and care is taken to ensure good electrical contact with the internal semiconductor layer. Alternatively, separate strands may be in alternating electrical contact with the internal semiconductor layer.

Manufacturing a transformer or reactor winding from a cable as described above requires a significant difference in terms of electric field distribution between the conventional power transformer / reactor and the power transformer / reactor according to the present invention. Occurs. A decisive advantage of the windings formed by the cable according to the invention is that the electric field is sealed in the windings, and thus there is no electric field outside the outer semiconductor layer. The electric field achieved by the current-carrying conductor occurs only in the solid main insulator. From both a design and manufacturing perspective, this has the following considerable advantages:-The windings of the transformer can be formed without having to take into account any electric field distribution,
The transposition of the wires mentioned in the background section can be omitted;-the transformer core design can be formed without having to take into account any electric field distribution;-no oil is required for the electrical insulation of the windings, ie The medium surrounding the windings may be air; no special connection is required to make an electrical connection between the external connection of the transformer and the coil / winding connected adjacently. Because, in contrast to conventional plants, this electrical connection is integral with the windings; the manufacturing / testing techniques required for the power transformer according to the invention are conventional. It is much simpler than that of a power transformer / reactor, because the impregnation, drying and vacuum treatments mentioned in the background section are not required.

When the present invention is applied as a rotary electric machine, the heat load on the stator is significantly reduced. Therefore, a temporary overload on the machine is not very dangerous, and it is possible to drive the machine with the overload for a long time without causing damage. This means that it is a significant advantage for plant owners who are currently obliged to switch to other equipment quickly in the event of operational disruption to ensure legally regulated transmission requirements. .

With the rotary electric machine according to the invention, the maintenance costs are considerably reduced, because there is no need to include transformers and circuit breakers in the system to connect the machine to the power network. Because.

In the above, it has been described that the winding cable outer semiconductor layer is intended to be connected to the ground potential. The purpose is to maintain this layer at substantially ground potential over the entire length of the wound cable. The outer semiconductor layer can be divided by applying it to a plurality of portions, each of which is distributed along the entire length of the winding cable, each individual layer portion being directly connectable to ground potential. In this way, better uniformity is achieved along the entire length of the wound cable.

In the above, it has been described that the solid insulator and the inner and outer layers can be achieved, for example, by extrusion. However, other techniques are also possible, for example, by spraying the material on a conductor / winding to form these inner and outer layers and insulators, respectively.

The wound cable is preferably designed to have a circular cross section. However, if it is desired to achieve better packing density, other cross-sectional shapes may be used. To create a voltage in the rotating electric machine, the cables are arranged in a plurality of successive turns in slots of a magnetic core. The windings can be designed as multilayer concentric cables to reduce the number of coil end crossings. The cable may be made of tapered insulation to make better use of the magnetic core, but in this case the shape of the slot will be adapted to the tapered insulation of the winding.

The great advantage of the rotary electric machine according to the invention is that the E-field is almost zero in the coil end area outside the external semiconductor and that the electric field has to be controlled since the external casing is at ground potential. That is not. This means that the field cannot be concentrated in the sheet, in the coil end region, or in the transition region between them.

In the method of manufacturing the device according to the invention, a flexible cable threaded into the opening of the slot of the magnetic core of the rotating electric machine is used as a winding. Because the cable is flexible, it can be bent, thereby allowing the cable to fit within multiple turns of the coil. Then, the coil end will consist of the bent area in the cable. The cable can also be spliced such that its properties remain constant over the entire length of the cable. This method involves considerable simplification compared to the state of the art. So-called label bars are not flexible but must be shaped as desired. Insulation and coil impregnation are also very complex and expensive techniques when manufacturing rotary electric machines today.

In summary, the electromagnetic device in the form of a rotary electric machine according to the invention therefore has a considerable number of significant advantages over the corresponding models according to the prior art. First, the machine according to the invention can be connected directly to the power network at any type of high voltage. Another important advantage is that the ground potential, at least part of the winding, and preferably throughout, is conducted consistently,
This means that the coil end area can be reduced in size, and that the brace means in the coil end area can be set to substantially the ground potential. Yet another important advantage is that oil-based insulation and cooling systems are eliminated in the rotating electric machine as already described above in connection with the power transformer / reactor. This means that there are no sealing problems and that the previously described dielectric ring is not required. It is also important that any forced cooling can be performed at ground potential.

[0041]

[Description of preferred embodiments]

 Embodiments of the present invention will be described below in more detail with reference to the accompanying drawings.

The electromagnetic device shown in FIG. 1 has the properties of a transformer. It is magnetic circuit 1 and 2
Electrical circuits 2, 3 each of which has at least one coiled winding 4
And 5.

It is shown in the figure that the transformer comprises a magnetic core 6. The core consists of a set of magnetic sheets to reduce eddy current losses. However, it should be noted that the presence of a core is not necessary for applications of the present invention. Therefore, air-wound embodiments and the like are sufficiently possible within the scope of the present invention. From this it can be seen that the term magnetic circuit is interpreted in a broad sense. So the term in question is
It only means that the magnetic field generated by the presence of the windings 4, 5 can generate a magnetic flux.

The device according to the invention comprises a device, generally indicated at 7, for controlling a transformer.
This controller 7 is adapted to control the frequency, amplitude and / or phase of the power output from the transformer.

In the illustration, the electric circuit 2 forms the primary side of the transformer, while the electric circuit 3 forms the secondary side of the transformer. The output power from the device therefore passes through a second circuit 3 coupled with a load, generally indicated at 8. This load can have any characteristic, such as power distribution and grid, as well as the consumer himself.

The control device 7 includes means 9 for controlling the magnetic flux in the magnetic circuit 1. Control means 9
Includes, in an application, at least one control winding inductively connected to the magnetic circuit 1. In the example, this control winding 9 is wound on a part of the core 6. In a coreless transformer embodiment, the control winding 9 is combined with the primary and secondary windings 4,5 so that the magnetic flux in the coreless magnetic circuit is inductively coupled with the control winding 9.

The control device 7 according to a preferred embodiment of the present invention is considered to be of the active type,
That is, the controller 7 can be adapted to actively control the magnetic flux in the magnetic circuit 9 through the control winding 9 to obtain desired characteristics. The control device 7 then preferably comprises an external power supply, so that the control device 7 can control the magnetic flux through the magnetic circuit 1 by generating a current flowing through the winding 9. The invention is particularly preferably used for high voltage applications. This means that relatively high voltages are usually associated with the electric circuits 2 and 3. However, for the purpose of control in such a case, it is sufficient for the control device 7 to generate a relatively high current flowing in the winding 9 at a relatively low voltage. The control device 7 can be adapted to perform the addition of magnetic flux to the magnetic flux in the magnetic circuit 1 for control purposes. The addition of the magnetic flux is made to a separately generated magnetic flux. By appropriately controlling the addition of the magnetic flux, the secondary circuit 3
The desired parameters for the power output through are achieved. The device 7 can be adapted to receive information about the voltage in the secondary circuit and / or to the load 8 from the voltage measuring device 10 as a basis for its control function. The current measuring member 11 measures a current in the secondary circuit 3. As described above, the addition of the magnetic flux generated through the control device 7 is performed based on the frequency of the power output through the secondary circuit 3,
Can be used to control amplitude and / or phase.

It should be noted that the controller 7 can be adapted to obtain an external control command via the input 12.

It should further be noted that the control device 7 can be adapted to provide passive control through the control winding 9. Passive control in this regard means that no external power supply is used for control. At this point, it should be noted that the control device 7 can couple one or more passive elements, such as resistors, capacitors or inductances coupled in series or in parallel, over the control winding 9. Such a passive element, which is coupled to the control winding 9 to suit its purpose, thus has a different effect on the magnetic flux, which in turn thereby differs in frequency, amplitude and / or phase with respect to the power from the device. The result comes.

It can also be seen from FIG. 1 that the device on the primary side includes a voltage measuring device 13 and a current measuring device 14 similar to those on the secondary side.

FIG. 2 shows that the magnetic circuit 1 comprises a core 6, which in addition to the secondary leg of FIG. 1 at 15 and the primary leg at 17, further comprises a leg 16. An embodiment of a transformer is shown that differs from FIG. This therefore means that the core 6 of FIG. 2 forms two different flux paths, indicated generally at 18 and 19, respectively. The control winding 9a is in this case arranged around the central leg 16, i.e. in the flux path 18 through the primary winding 4 of the transformer. The secondary flux path 19 conversely passes through the secondary winding 5 and around the control winding 9a. In turn, it is possible to act on the magnetic flux in the leg 16 via the control device 7 using the control winding 9 a, thereby also affecting the magnetic flux in the leg 15 via the secondary winding 5. In other words, the control winding 9a is now only connected to one of the two flux paths.

The modification in FIG. 3 is obtained by further adding a control winding 9b2 to the winding 9b1. These two control windings are arranged around their own legs 16b, 15b, ie these control windings 9b1 and 9b2 belong to their own flux paths 18,19. The control device 7b includes a control unit 20, which also has control elements 2 associated with the control windings 9b1 and 9b2, respectively.
1 and 22 are controlled. By actively or passively controlling the control elements 21, 22 through the control unit 20, the magnetic flux is adjusted to pass through only one of the flux paths 18, 19 or to diverge to the same side.

In FIG. 3, the secondary winding 4 b of the transformer comprises two or more winding parts 23 and 24 each connected in series. The magnetic flux in both flux paths 18, 19 passes through main winding section 23, but only the magnetic flux in flux path 19 passes through winding section 24. This therefore means that there is no magnetic flux passing through the winding portion 24 when the magnetic flux can only pass through the leg 16b by the control windings 9b1 and 9b2. Thus, this means an output voltage that is lower than the voltage that results in an operating condition in which the entire flux passes through the flux path 19 than if the entire flux passes through both the secondary winding portions 23 and 24. Thus, in such an operating state, it means that the control winding 9b1 has completely or at least partially interrupted the magnetic flux passing through the leg 16b.

FIG. 4 shows an embodiment of a reactor somewhat reminiscent of the transformer according to FIG. The difference is that the reactor does not have any secondary side, instead its power winding is split into two winding parts 25,26.
As in the previous example, there are two control windings 9c1 and 9c2, which control the magnetic flux to pass through winding portion 26 to the desired extent. All the magnetic flux always passes through the winding portion 25.

FIG. 5 shows a very simple generator embodiment, the rotor of which is indicated at 26. In this example, this rotor is considered as a permanent magnet rotor. However, it can also be designed as a rotor with field windings. The magnetic circuit 1d here comprises an electric output circuit 5d inductively coupled to the magnetic flux in the core 6d. The core 6d has a portion adjacent to the rotor 26, and the permanent magnet generates a magnetic flux in the core during rotation of the rotor. This magnetic flux passes through the output winding 5d and produces an output effect there. The control device 7d has a control winding 9d inductively coupled to the magnetic flux circuit 1d as described above.
including. Voltage and current measuring devices 10d and 11d, respectively, are also installed to manage the output power. By using the control device 7d, the control winding 9d is in turn necessary for the control to passively or actively impart the desired characteristics of frequency, amplitude and / or phase to the output power from the generator. The target of the function.

Note that what is shown in the figure is a very simple, ie, single-phase, embodiment. The actual embodiment is a more complex, specifically a multi-phase embodiment.
The number of windings and winding sections is much higher than previously discussed for the number of control windings as well as the primary and secondary windings. The design of the magnetic circuit is also changed due to its functional requirements.

It should be particularly noted that at least one of the windings installed according to the invention is surrounded by two spaced-apart equipotential layers and a solid insulator placed between them. The inclusion of an insulated conductor means that the electric field around the conductor is substantially confined within the cable so that the primary and secondary windings can be placed with very great freedom anywhere on the magnetic circuit. Even intermediate insertion of the windings is possible. Thus, the controller is effective for both core and shell type transformers.

Especially for high voltage applications, the winding design just described is suitable. Usually, the control winding (control windings) 9 has a lower potential than the power windings, so that the control winding (control windings) 9 does not necessarily have at least one insulator, such as a power winding. There is no need to have a system.

An important aspect which makes it possible to provide an electromagnetic device according to the invention is to use a conductor cable having a solid electrical insulator for at least one of the windings. This includes
An internal semiconductor layer or casing is provided between the insulators, one or more conductors disposed therein, and an external semiconductor layer or casing disposed outside the insulator. Such cables are used as standard cables in other useful power engineering or power transmission fields. First, a short description of a standard cable will be given to enable description of the embodiments. The internal conducting conductor includes a plurality of strands. Around the strand is a semiconductor inner layer or casing. Around this semiconductor inner layer is an insulating layer of a solid insulator. The solid insulator is formed of a polymer material having low electrical loss and high penetration resistance. Specific examples include polyethylene (PE) and especially cross-linked polyethylene (XLPE) and ethylene propylene (EP). A metal shield and an outer insulating casing are provided around the outer semiconductor layer. The semiconductor layer includes a conductive component such as conductive soot or carbon black,
For example, it is made of a polymer material such as an ethylene copolymer. Such a cable is hereinafter referred to as a power cable.

A preferred embodiment of a cable intended for winding in a rotating electric machine is shown in FIG. The cable 41 is shown as including a current-carrying conductor 42 that includes transported non-insulated and insulated strands. Electromechanically crossed and tightly insulated strands are also possible. These strands can be twisted and intersected in multiple layers. Surrounding the conductor is an internal semiconductor layer 43, which is further surrounded by a homogeneous layer of solid insulating material. The insulator 44 does not use any liquid or gas type insulating material. This layer 44 is surrounded by an external semiconductor layer 45. Cables used as windings in the preferred embodiment may include, but are not required to have, metal shields and jackets. In order to avoid induced currents and associated losses in the outer semiconductor layer 45, this is cut off at the coil ends, ie at the transition from the stack of sheets to the end winding. The disconnection is performed such that the external semiconductor layer 45 is divided into several parts distributed along the cable, and is completely or partially electrically separated from each other. Each of the decoupling portions is connected to ground, whereby the external semiconductor layer 45 is maintained at or near ground potential over the entire length of the cable. This means that, around a winding completely insulated at the coil end, the contactable surface and the dirty surface after several uses have a negligible potential with respect to ground, and they have a negligible electric field. Only means that

In order to optimize the rotating electrical machine, the design of the magnetic circuit for each of the slots and teeth is of critical importance. As mentioned above, the slot should be connected as close as possible to the casing on the coil side. It is also desirable that the teeth at each radial level be as wide as possible. This is important for minimizing machine losses and magnetization requirements.

Given the availability of winding conductors, such as the aforementioned cables, there is great potential to optimize the magnetic core in several respects. The magnetic circuit in the stator of the rotating electric machine will be described below. An axial end view of the sector / pole pitch 46 of the machine according to the invention is shown in FIG. A rotor with rotor poles is shown at 47. In a conventional method, the stator consists of a laminated core of electrical sheets, which in turn consist of sector-shaped sheets. A number of teeth 49 located at the outermost end from the core back portion 48 extend radially in and out of the rotor. There is a corresponding number of slots 50 between the teeth. In particular, by using the cable 51 according to the above, the depth of the slots for high-voltage machines can be made greater than is possible in the state of the art. As the need for cable insulation decreases in the direction of the rotor for each winding layer, the slots have a cross-sectional shape that tapers in the direction of the rotor. As you can see from the figure, the slots are virtually
It consists of a circular cross section 53 around each winding layer with a narrow waist 53 between the layers. The cross section of such a slot is suitably referred to as a "cycle chain slot". Insulation and anchoring of cables because relatively high layers are required in such high voltage machines and the availability of cables with appropriate dimensions, adequate insulation and external semiconductors is limited. Achieving the intended continuous tapering of each of the child slots is not really easy. In the embodiment shown in FIG. 7, a cable having three different sized cable insulations is used and placed in three correspondingly sized cross-sections 54, 55, 56. That is, a modified cycle chain slot is obtained. It can also be seen from the figure that the stator teeth 49 can be shaped with a substantially constant radial width along the depth of the entire slot.

Again, note that the windings represented by 54, 55, 56 in FIG. 7 correspond to the windings represented by 5d in FIG. Conversely, one or more windings corresponding to control winding 9 in FIG. 5 are represented by 40 in FIG. In this embodiment, these control windings 40 are disposed radially outermost from the rotor. Control winding 9 is connected to 4 in FIG.
Note that it is not necessary to place it at the location represented by zero.

In an alternative embodiment, the cable used as the winding may be a conventional power cable, such as the power cable described above. At this time, the grounding of the external semiconductor layer 45 is performed by peeling the metal shield and the jacket of the cable at appropriate positions.

The scope of the present invention applies to many alternative embodiments based on available cable dimensions as far as insulators and outer semiconductor layers are concerned. Embodiments having a so-called cycle chain slot can be modified in more than the manner described here.

As mentioned above, the magnetic circuit can be located in the stator and / or rotor of the rotating electric machine. However, the design of the magnetic circuit depends on whether it is a stator and / or
Or to a large extent irrespective of whether they are arranged in the rotor or not.

For the winding, it is desirable to use the winding described as the winding of the multilayer coaxial cable. In such a winding, the number of intersections at the coil ends is
Minimization is achieved by placing all coils in the same group radially outward from each other. This also facilitates the method of manufacturing and threading stator windings in different slots. The windings are obtained by a relatively simple threading operation in which the flexible cable is threaded into the opening 52 in the slot 50, since the cable used in accordance with the invention relatively easily gains flexibility.

FIG. 8 shows a simple basic diagram of the electric field distribution around the windings of a conventional power transformer / reactor. There, 57 represents a winding, 58 represents a core, and 59 represents an equipotential line, ie a line where the electric field is of the same magnitude. The portion below the winding is considered to be ground potential.

Since the potential distribution is necessary for sufficient insulation between adjacent turns of the winding and between each turn and ground, the potential distribution determines the configuration of the insulator system. Thus, the figure shows that the upper part of the winding has a higher insulation load. Thus, the design and position selection of the winding, as compared to the core, is substantially determined by the electric field distribution in the window of the core.

A cable that can be used for windings housed in a dry power transformer / reactor according to the present invention is shown in FIG. As already mentioned, the cable can be provided with other additional outer layers for specific purposes, for example to prevent excessive electrical loading on other areas of the transformer / reactor. In terms of geometric size, the conductor area of the cable is between ² and 3000 mm ² and the diameter of the outer cable is between 20 and 250 mm
It is.

The power transformer / reactor windings made from the cables described in the Summary of the Invention can be used for all single-phase, three-phase, and polyphase transformers / reactors, regardless of the core shape. Can be used. One embodiment is shown in FIG. 8, which shows a three-phase stacked core transformer. The core is a rim 60 of three cores as in the conventional type,
61 and 62 and support yokes 63 and 64. In the embodiment shown, both the core rim and the yoke have a tapered cross section.

The winding on which the cable is formed is coaxially arranged around the core rim. As can be seen, the embodiment shown in FIG. 9 has three coaxial winding turns 65, 66 and 67. The innermost winding 65 represents the primary winding and the other two windings 63,6
4 represents a secondary winding. The winding connections are not shown in order to avoid obscuring the figure. Otherwise, in the present embodiment, spacing bars 68 and 69 having several different functions are arranged at predetermined positions around the winding. The spacing bar can be made from an insulating material to maintain a predetermined spacing between turns of the coaxial winding for purposes such as cooling and support. They may also be made from conductive materials to form part of the winding grounding system.

FIG. 9 does not show the control winding 9.

Design of Other Cables In a modification of the cable shown in FIG. 10, the same reference numerals as before are used, with the addition of the letter a, which is unique to this embodiment. In this embodiment, the cable is an insulator 4
4a includes several conductors 42a separated from each other. In other words, the insulator 44a functions as an insulator between the individual adjacent conductors 42a and an insulator between them. The different conductors 42a can be arranged in different ways, thereby allowing the overall cross-sectional shape of the cable to be changed. In the embodiment according to FIG. 10, the conductors 42a are arranged in a straight line, resulting in a relatively flat cable cross-sectional shape. From this, it can be concluded that the cross-sectional shape of the cable is deformable in a wide range.

In FIG. 10, it is considered that a voltage lower than the phase voltage exists between the adjacent conductors. That is, conductor 42a in FIG. 10 is considered to be formed by different rotations of the windings, so that the voltage between adjacent conductors is relatively low.

As before, a semiconductive outer layer 45a made of a solid electrically insulating material is provided outside the insulator 44a. An inner layer 43a of semiconductive material is disposed for each of its conductors 42a, ie, each of these conductors has an inner semiconductive layer 43a surrounding itself. This layer 43a thus functions for potential equalization as far as the individual conductors are concerned.

In the modification of FIG. 11, the same reference numerals as before are used, with the addition of a letter b specific to this embodiment. Again, some or three conductors 42b are provided. A phase voltage, ie a voltage substantially higher than the voltage developed between the conductors 42a in the embodiment according to FIG. 10, is considered to be present between these conductors. FIG.
In No. 1, an internal semiconductive layer 43b in which a conductor 42b is disposed is provided. Each of the conductors 42b, however, is surrounded by its own additional layer 70, which has properties corresponding to those described above with respect to the inner layer 43b. An insulating material exists between each additional layer 70 and the layer 43b disposed therearound. Therefore, this layer 43b functions as a potential equalizing layer outside the additional layer 70 of the semiconductive material belonging to the conductor, and the additional layer 70 is connected to each conductor 42b and located at the same potential as the conductor.

Possible Variations It is clear that the invention is not limited to the embodiments described above. Accordingly, those skilled in the art will recognize that many detail changes may be made, provided that this basic concept of the invention is maintained without departing from the basic concept defined in the appended claims. As an example, it should be noted that the present invention is not limited to only the particular material choices exemplified above. Thus, functionally equivalent materials may be used instead. For the creation of the insulator system according to the invention, other techniques than extrusion and spraying are also possible, as long as the intimacy between the various layers is reached. Note that additional equipotential layer arrangements are possible. For example, one or more equipotential layers of semiconducting material may be "inside" and "outside"
Can be placed in the insulator between these layers. According to the invention, the control winding 9 is usually not necessarily the same as described above, as a result of the fact that the control winding or control windings are usually at a lower potential than the other windings of the electromagnetic device. It should also be noted that it need not be formed by a flexible cable, such as a cable. Specifically, the other windings are truly high voltage windings. In other respects, it should be noted that the exact control principle in performing the method according to the invention can be varied within the scope of the intended control function.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a device according to the invention in a transformer.

FIG. 2 is a circuit diagram of a modified example of a transformer.

FIG. 3 is a circuit diagram of a further modification of the transformer.

FIG. 4 is a circuit diagram of an embodiment similar to the modification of FIG. 3, but involving a reactor.

FIG. 5 is a circuit diagram showing an embodiment of a generator.

FIG. 6 is a diagram showing components included in a standard cable whose current capacity has been modified.

FIG. 7 is a diagram of an axial end of a sector / pole pitch of a magnetic circuit according to the present invention.

FIG. 8 is a diagram showing an electric field distribution around a baseline of a conventional power transformer / reactor.

FIG. 9 is a perspective view showing an embodiment of a power transformer according to the present invention.

FIG. 10 is a cross-sectional view of a cable structure having a plurality of conductors obtained by modifying the embodiment of FIG. 1;

11 is a cross-sectional view of a further cable structure including a plurality of conductors, but having a different arrangement than the embodiment of FIG.

[Explanation of symbols]

 1, 2 Magnetic circuit 3, 4 Electric circuit 4, 5 Coiled winding 6 Core 7 Device 8 Load 9 Control winding 10, 13 Voltage measuring device 11, 14 Current measuring member 12 Input 15 Leg (secondary side) 16 Leg 17 Leg (primary side) 18, 19 Magnetic flux 20 Control unit 21, 22, Control element 23, 24, 25, 26 Winding part 41 Cable 42 Conductive conductor 43 Internal semiconductor layer 44 Insulator 45 External semiconductor layer 46 Magnetic pole pitch 47 Rotor 48 Back part 49 Teeth 50 Slot 51 Cable 57 Winding 58 Core 59 Equipotential line 60, 61, 62 Rim 63, 64 Support yoke 68, 69 Spacing bar 70 Additional layer

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GE, GH, GM, HR, HU, ID, IL, IS, JP, KE, KG, KP , KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZWF Term (reference) 5E043 AA02 AB01 5E044 AA08 AC01 CA01 5H604 AA01 BB01 BB03 BB09 BB10 BB14 CC01 CC02 CC05 DA14 DA17 DB16 PB01 PD06 PD07

Claims (36)

[Claims] 1. An electromagnetic device comprising at least one magnetic circuit (1) and at least one electric circuit (2, 3) comprising at least one winding (4, 5), said electromagnetic circuit comprising: The electric circuits are inductively connected to each other and the device comprises a controller (7) for controlling the operation of the device; the controller (7) controls the magnetic flux in the magnetic circuit Means for controlling the frequency, amplitude and / or phase of the power transferred to and from the device by the controller comprising means (9) for controlling the at least one winding (4,
5) or at least one part thereof having an insulator system including an electrical insulator (44) formed inside the inner layer (43) by a solid insulating material.
Two conductors (42); said at least one conductor (42) comprising said inner layer (42).
43); and said inner layer is lower than the conductivity of said conductor, but sufficient for said inner layer (43) to cause an equalizing effect on an electric field outside said inner layer. An electromagnetic device having electrical conductivity. 2. The device according to claim 1, wherein said control means comprises at least one control winding (9) inductively connected to said magnetic circuit. 3. The device according to claim 1, wherein the controller is configured to control reluctance in the magnetic circuit. 4. The device according to claim 1, wherein the control device is configured to add a magnetic flux to a magnetic flux in the magnetic circuit. 5. A magnetic circuit comprising a material having a magnetic permeability of more than one, and wherein said control device (7) comprises one or more sections of said magnetic circuit having a variable magnetic permeability. 4. The device of claim 3, wherein the device is configured to control reluctance in the magnetic circuit by changing the magnetic permeability of the device. 6. The device of claim 5, wherein the one or more areas having variable magnetic permeability include one or more gaps in the magnetic circuit. 7. The device according to claim 1, wherein the magnetic circuit has no magnetic core. 8. The device according to claim 1, wherein the winding is wound around a magnetic core. 9. The control winding (9) and the windings (4, 5) of the electric circuit are arranged such that substantially the same magnetic flux passes therethrough. The device according to any one of 1, 3 to 8, above. 10. The device is configured to control, by the at least one control winding, a frequency, amplitude and / or phase with respect to power flowing in the windings (4, 5) of the electrical circuit. The device according to claim 1, wherein a reactor is formed. 11. The electric circuit (2) comprising at least two windings (2) coupled in series.
3, 24); wherein the magnetic circuit comprises at least two alternating flux paths (18,
19); the at least one control winding controls the magnetic flux to pass through one or both of the flux paths; and the two windings of the electrical circuit include one of the two windings. 11. The device according to claim 1, wherein the at least one control winding is arranged to be decoupled from the magnetic flux by the at least one control winding. 12. 12. The device according to claim 1, wherein the magnetic circuit is arranged in a stator or a rotor of a rotary electric machine. 13. The magnetic circuit (1) belongs to a transformer having a primary winding and a secondary winding (4, 5); and the primary and secondary windings and the control winding (9) are the same. Device according to any of the preceding claims, arranged to be passed by a magnetic flux. 14. In a transformer, said secondary winding of said transformer comprises at least two winding portions coupled in series; said magnetic circuit comprising at least two alternating flux paths (18, 19). At least two generated control windings (9b1,
9b2, 9c1, 9c2) controls the magnetic flux to pass through one or both of these paths; and the two winding paths of the secondary winding are controlled by the control winding of the winding paths. A device according to any of the preceding claims, characterized in that one of the devices is arranged such that it can be disconnected from the magnetic flux. 15. The device includes a magnetic core having at least three legs coupled in parallel; and two of the legs belong to separate flux paths, and a third leg is connected to the two legs. The device according to claim 11, wherein the device is common to a magnetic flux path. 16. The insulator system external to the insulator includes an outer layer (45) having a higher conductivity than the insulator to provide a ground potential or other relatively lower potential. The device according to any one of claims 1 to 15, wherein the device is operable to equalize a potential by connection with the device. 17. The method according to claim 16, wherein the outer layer is arranged to substantially surround an electric field generated by the conductor inside the outer layer. Item 1
The device according to any one of claims 16 to 16. 18. The device according to claim 1, wherein the inner layer and the solid insulator exhibit substantially equal thermal properties. 19. The device according to claim 1, wherein the outer layer and the solid insulator exhibit substantially equal thermal properties. 20. The device according to claim 1, wherein the at least one conductor forms at least one dielectric winding. 21. The device according to claim 1, wherein the inner layer and / or the outer layer comprise a semiconductor material. 22. The method according to claim 19, wherein the inner layer (43) and / or the outer layer (45) is 10 ^{−6 to} 100
The device according to any of the preceding claims, characterized in that it has a resistivity in the range of K? Cm, preferably ^{10-3 to} 1000? Cm, preferably 1 to 500? Cm. 23. The method according to claim 20, wherein the inner layer (43) and / or the outer layer (45) have a resistivity in the range of 50 μΩ to 5 MΩ per meter length of the conductor / insulator system. Item 23. The device according to any one of Items 1 to 22. 24. The method according to claim 1, wherein the solid insulator and the inner layer are formed of a polymer material. The described device. 25. The inner layer (43) and / or the outer layer (45) and the solid insulator (44) have substantially the entire boundary so as to ensure adhesion even during bending and temperature changes. 1 and 2 are rigidly connected to each other.
5. The device according to any one of 4. 26. The solid insulator and the inner layer and / or the outer layer are formed of a material having a high modulus of elasticity that maintains mutual bonding during strain during operation. A device according to any of the preceding claims. 27. The method according to claim 1, wherein the solid insulator and the inner layer and / or the outer layer are made of a material having a substantially equal E modulus. device. 28. The method according to claim 28, wherein the inner layer (43) and / or the outer layer (45) and the solid insulator (44) are formed of a material exhibiting substantially equal coefficients of thermal expansion. A device according to any of the preceding claims. 29. A flexible cable (41) wherein said inner layer (42) and its insulation system are flexible.
Device according to any of the preceding claims, comprising a winding formed by: 30. Device according to claim 1, wherein the inner layer (43) is in electrical contact with the at least one conductor (42). 31. The at least one conductor (42) includes multiple strands and the conductor (42)
) Is at least partially not insulated and the inner layer (4)
Device according to claim 30, characterized in that it is in electrical contact with 3). 32. The conductor (42) and its insulation system are designed for high voltages, preferably higher than 10 kV, in particular higher than 36 kV, preferably higher than 72.5 kV. A device according to any of the preceding claims, characterized in that it is located. 33. The machine according to claim 12, wherein the magnetic circuit comprises one or more magnetic cores (48) having slots (50) for the windings (41). 34. The device according to claim 12, comprising a generator, a motor or a synchronous compensator. 35. A power supply for high voltages, preferably higher than 36 kV, connected directly without an intermediate transformer.
A device according to any of the preceding claims. 36. The device according to claim 1, wherein the device is constituted by a power transformer / reactor.