FI118398B - Method and arrangement for making a choking coil and choking coil - Google Patents

Description

118398

Method and arrangement for making a choke and a choke

Background of the Invention

The invention relates to a method of making a choke, the method comprising forming at least one coil having conductor layers and an inner sheath of fibrous reinforcement material and resin and an outer sheath of fibrous reinforcing material and resin.

A further object of the invention is an arrangement for making a choke, the arrangement comprising means for winding the insulated conductor to form a conductor layer to provide a coil.

The invention further relates to a choke having at least one winding having conductor layers and an inner sheath on the inside and an outer sheath on the outside.

Dry insulated air-core chokes are used in a wide variety of applications. The chokes can be used, for example, as damping chokes in connection with compensation capacitor units, as filter chokes for filtering harmonics in the mains and as parallel chokes to compensate for the capacitive reactive power of transmission lines. Further, the chokes can be used in many filtration sites as current limiting devices. In addition, the inductors have many other applications.

20 Fl publication 70755 discloses a choke whose coil is formed · · * · *. bundles of wires. A permeable insulating material is provided around the coil, which may be, for example, of fiberglass. The insulation material is impregnated with

! ·. *: Resin. Similar reactors are also disclosed in EP

• · · 0084412 and Fl 91570. The formation of coils from conductor wood makes it difficult to • * ·! * Y 25 coil precise dimensioning. For example, a small change in capacitance in a choke • · · · · · · · · · · · · · · · · · · · · · · · · · · · · · It is particularly difficult to get the resin impregnated at any point around the throttle and between the conductors. Thus, the choke is reasonably difficult to manufacture and is quite demanding to make the choke sufficiently rigid in its mechanical structure.

BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a novel type of ·: ··: solution for the manufacture of a choke and a new type of choke.

·: * ·· The process of the invention is characterized in that a fiber reinforcing material strand wound on an outer sheath, wrapped in an outer sheath, wrapped in an outer sheath, wetting fibrous reinforcing wire yarn into an epoxy or polyester resin and wrapping an interlayer layer of fibrous reinforcing yarn woven into an epoxy or polyester resin onto the conductor layer, wrapping the outer layer of the conductor or conductors, reinforcing material yarn in epoxy or polyester resin and wrapped outside of the outer conductor layer with a fibrous reinforcement wetted with epoxy or polyester resin outer casing of meal wire.

Further, the arrangement of the invention is characterized in that the arrangement includes means for wetting the fibrous reinforcing material yarn into the epoxy or polyester resin and the fibrous reinforcing material yarn wetted into the epoxy or polyester resin to form the inner sheath of the coil and the outer sheath.

Further, the inductor according to the invention is characterized in that the inner sheath and the outer sheath are formed by wrapping a fibrous reinforcement material wetted with an epoxy or polyester resin and that there are intermediate layers between the conductor layers formed by an epoxy or polyester resin wetted fiber.

·· f: V In the solution shown, the throttle is formed by winding a resin-wetted fibrous reinforcement material, **: *, for example, in the first step: for example, a roving yarn in the form of a cylinder. The insulating layer thus formed is wound with an insulated conductor to form a conductor layer. Wiring:. ·. a layer of resin-impregnated fibrous reinforcing material, such as roving yarn, is wound again on top of the layer. Again, a layer of insulated conductor is wound onto the intermediate layer. The insulated conductors are wound with at least two layers, but there may be several layers of conductors. An interlayer of fibrous reinforcement material, for example roving, is wound between each layer of conductor • ·: 30. An outer layer of fibrous reinforcement material, such as roving •. · * ·, Is wound on the outer layer of conductor. yarn. As shown, the resin can be applied uniformly to the choke on all sides. Also, very good resin insulation between the conductors, especially the conductor layers, is obtained. All in all, the throttle structure is very sturdy. Implementation of the solution is also reasonably easy to automate, 3 118398, saving considerable manufacturing costs. Further, the solution can be implemented under normal atmospheric pressure, i.e. without overpressure and underpressure, and nevertheless the resin is very well sandwiched between the conductors.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be explained in more detail in the accompanying drawing, in which Figure 1 schematically shows a top view of a throttle, Figure 2 schematically shows a side view and a cross-section of a throttle, and Figure 3 schematically shows a solution for manufacturing.

Detailed Description of Some Embodiments of the Invention

Figure 1 shows a choke 1. The choke 1 is a dry insulated and air-core choke. The choke 1 can be used, for example, as a damping choke for parallel compensation capacitor batteries, or as a filtering data choke to filter harmonic harmonics from power distribution networks. Further, the inductor can be used, for example, as a parallel throttle to compensate for the capacitive reactive power of long, lightly loaded transmission lines. Further, the inductor 1 can be used as a current limiting inductor to limit the short-circuit current, for example in the case of power distribution networks, or the inductor 1 can be used for some other suitable application.

• ·

The choke 1 has at least one cylindrical coil 2, but • · [· /. the inductor may also have a plurality of nested cylindrical coils 2.

. *. * In the case of Fig. 1, the throttle 1 has three nested cylindrical • • · * / \: coils 2. The coils 2 are separated from each other by means of insulating material supports 3.

• · · 25 This provides an air gap between the coils 2 to ensure cooling of the choke 1. The coils 2 are connected to the end rails 4 in a manner known per se. Typically, the coils 2 are connected in parallel.

Each coil 2 is formed of insulated-coated conductors as shown in Figure 2. The conductors 5 may be, for example, aluminum or copper. The insulation over the conductors may be, for example, polyethylene terephthalate PET film, paper, enamel, aramid paper, polytetrafluoroethylene PTFE or other suitable, reasonably thin insulation. The inner part of the coil 2 is formed by an inner jacket ** and the outer part 7 of the coil 2 is formed by an outer jacket 7. The conductors 5 form conductive layers: 8. * There are intermediate layers 9 between the conductive layers 8.

4, 118398

The inner sheath 6 is formed by wrapping a resin-soaked roving yarn around a cylindrical mold. Subsequently, a conductor 5 is wrapped on the outside of the inner sheath to form a conductor layer 8. An intermediate layer 9 is also wrapped on the conductor layer 8, which is also formed of resin-wetted 5 roving yarns. Thereafter, the next conductor layer 8 is wrapped and the following intermediate layer 9 is wrapped thereon. The third intermediate layer 8 is wrapped around the second intermediate layer 9 and so on. On the outside of the fifth, which in this case is the outer conductor layer, an outer sheath 7 is formed. Also, the outer sheath 7 is formed of a resin-wetted roving yarn. Typically, the coils together have 1 to 20 conductor layers 8.

Fig. 3 schematically shows an arrangement for making a choke. The arrangement includes a cylindrical mold 10. The mold 10 is rotated about its axis to wrap the roving yarns 11. The roving yarns 11 are disengaged from the roving yarn coils 12. In the accompanying figures, only four roving yarn coils 12 are shown, but preferably, the roving yarns 11 are wound around the mold 10 at the same time, for example, about 10-50 pieces. The weight of the ro-wing yarn 11 per unit length, i.e. the yarn number, is, for example, about 400 to about 2400 tex. For example, using 40 roving yarns 11, the roving yarns can be spread over the mold 10 as a mat of several centimeters. Prior to winding the mold 10, the roving yarns 11 are dipped in resin 13. The resin may be, for example, an epoxy resin or a polyester resin.

For example, watering of the roving yarns may be done by placing the resin 13 in the vessel 14. A cylinder 15 is fitted over the vessel 14, the underside of which contacts the resin 13, and the cylinder 15 rotates to irrigate the roving yarns 11 passing through it. A plurality of layers of roving yarn 11 soaked in resin 13 are wound around the mold 10. In this way, the thickness of the inner sheath 6 can be varied, for example, between 1 and 10 mm.

• ·

Once the inner sheath 6 has been formed, the first conductor layer 8 is wound over it. The conductor layer 8 is formed by an insulated-coated conductor 5 which is disengaged from the conductor coil 16. Figure 3 shows two conductors 5 to be wound simultaneously in parallel. For example, the diameter of the conductor 5 may be, for example, 1-5 mm when using a circular conductor "* t 5. The conductor 5 may, of course, also be square or rectangular.

* | Figure 3 shows the simultaneous winding of the roving yarns 11 and the conductor 5, but in practice the winding is not usually done simultaneously, but first the inner sheath 6 is formed and the roving yarns 11 are cut and then the wire 5 and so on are wound.

After the conductor layer 8 is formed, the conductor 5 is cut off. Then the intermediate layer 9 is wound on the roving yarns 11 made with resin 13 and the next conductor layer 8 is wrapped again on the intermediate layer 9, etc. The thickness of the intermediate layer 9 is e.g. 0.1 - 0.2 mm. The thickness of the intermediate layer 9, i.e. the distance 5 of the conductors 5 from two different conductor layers 8, is preferably as small as possible. In this case, the intermediate layer 9 may be so thin that it does not need to be taken into account in the design calculation of the choke 10. On the other hand, the intermediate layer 9 also has thicker points which fill the cavities resulting from the cross-sectional shape of the conductors 5. Thus, there is preferably so much resin that there are substantially no air gaps between the conductor layers 8. The various conductor layers 8 are electrically connected to each other in a desired manner, either in series or in parallel with the outer shell 7. The outer sheath 7 has a thickness of about 1 to 10 mm. More resin 13 is applied to intermediate layer 9 than to inner liner 6 and outer shell 7. This means that when forming intermediate layer 9, the roving yarns 11 are wetted, i.e. more resin 13 is applied.

By applying more resin to the intermediate layers 9 than to the inner sheath 6 and the outer sheath 7, it is ensured that a resin is matched between each of the conductor layers 8. This ensures that the choke construction becomes extremely rigid.

: \ | The amount of resin 13 may be controlled, for example, by means of a scraper 17 J 25. The scraper 17 is disposed in the vicinity of the cylinder 15. By adjusting the controls ··· t:. on the road 18, the distance of the scraper 17 from the cylinder 15 is adjusted to the amount of resin 13 to be fitted to the roving yarns 11] * ·.]. When the scraper 17 is further away from the cylinder 15, there is more resin above the cylinder 15 to engage the roving yarns 11.

.. while the scraper 17 is fitted close to the cylinder 15, there is • 30 more resin on the cylinder 15 to grip the roving yarns 11. The amount of resin is affected by * ···! also the rotational speeds of the mold 10 and the cylinder 15. Mold 10 and cylinder 15 · * ·,. the rotation is also controlled by the control 18. The cylinder 15 may also rotate. · * ·. freely spun by roving yarns 11.

For the sake of clarity, Fig. 3 does not show the support structures *] 35 of the arrangement and other similar means, such as rotating means and, for example, robotic arms, by means of which the roving yarns 11 and the wires 5 are inserted. The roving yarns 11 and the conductors 5 can also be placed manually at the beginning of the winding. The resin 13 may be heated before wrapping to reduce the viscosity of the resin.

Once the innermost coil 2 has been formed, the insulating material supports 3 are fitted on the outside thereof, and then the inner coil of the next coil is wound on these supports 3 and on the inner coil 6 again a conductor layer 8, followed by an intermediate layer 9 etc.

If desired, the outer coils 2 can also be formed on the mold 10. The choke 1 is then formed by placing the finished coils 2 on top of one another and inserting insulating material supports 3 therebetween.

In addition to the roving yarns 11, axial fibers of the coil 2 are also fitted to the inner sheath 6 and the outer sheath 7. This increases the structural strength of the coil 2. When the coil is complete, the resin hardens. The curing of the resin can take place at room temperature, whereby the curing typically takes about a couple of hours. If desired, curing can be accelerated by heating the resin in the coil. After curing, the mold 10 may be removed. If the mold 10 is of suitable material, it can also be left inside the inner coil 2. Preferably, the conductor layers 8 are formed by wrapping one or more parallel conductor 20s in the axial direction. In this case, the mechanical solution of the arrangement is simple. Further, when dimensioning the choke, it is easy to change the characteristics of the * * t • V choke, if necessary, since, for example, only one strand of wire can be added instead of, for example, 10 bundles of wire. One layer of conductor 8: * · · · is thus formed by winding, for example, 1-40 conductors simultaneously.

• ·; It is still possible to form bundles of conductors with a plurality of conductors ··· t both axially and radially, but it is slightly more difficult to obtain a resin between each conductor to ensure structural t rigidity.

.. The diameter of the throttle 1 may vary, for example, between 30 cm and 4 m. · ·: ** 30 and the height of the throttle 1 may vary between 30 cm and 4 m. In this case, the weight of the inductor 1 typically varies between 5 kg and 15000 kg. The choke 1 · ** .. does not necessarily have to be an air core; also applies to the manufacture of an iron-core choke. The fibrous reinforcement material is most preferably roving yarn. Instead of a roving yarn, i.e. a non-twisted or * * 35 lightly twisted glass fiber bundle, another suitable glass fiber reinforcement may be used to make the throttle. Further, of the roving yarns, 7,118,398 are the most advantageous to use fully untwisted, i.e., straight-wound roving yarn. Hereby, for example, the glass fiber bundle spreads very well and evenly when forming the interlayer 9, whereby the interlayer is relatively thin. The further fibrous reinforcement material may be, for example, Kevlar or polyester. It is also essential that a wet blend of fibrous reinforcement material and resin be used in the manufacture.

In some cases, the features set forth in this application may be used as such, despite other features. On the other hand, the features disclosed in this application may be combined, if necessary, to form various combinations.

The drawings and the description related thereto are intended only to illustrate the idea of the invention. The details of the invention may vary within the scope of the claims.

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Claims (22)

8 118398 A method of making a choke comprising forming at least one coil (2) having conductive layers (8) and an inner sheath (6) of fibrous reinforcement material and resin and an outer sheath (7) of fibrous reinforcing material and resin at ul-5. by wetting the fibrous reinforcing material yarn into an epoxy or polyester resin (13) and wrapping the fibrous reinforcing yarn into an epoxy or polyester resin (13) wound an inner sheath (6), 10 wound from an insulated wire (5) or insulated outside the inner sheath (6); ) wire layer (8) wetted fibrous reinforcing wire to epoxy or polyester resin (13) and wound fibrous reinforcing wire wound into epoxy or polyester resin (13) onto wire layer (8), interlayer (9) or outer layer (9) a layer (8) of conductors following the conductors (5), wherein the conductor forming at least two layers (8) and forming an intermediate layer (9) between each conductor layer (8) and wetting the fibrous reinforcing material yarn into an epoxy or polyester 20 resin (13) and wrapping it outside the thinnest conductor layer (8) in an epoxy or polyester resin (13) kast outer sheath (7) of wetted fibrous reinforcing yarn. • t *; A method according to claim 1, characterized in that:: *: 25 the fibrous reinforcing material is fiberglass. Method according to claim 2, characterized in that tn ·. ···. that • · fiberglass is roving yarn (11). The method according to claim 3, characterized in that the roving yarn (11) is a straight-wound roving yarn. Method according to one of the preceding claims, characterized in that the · φ · conductor layer (8) is formed by winding a single conductor (5) or only 35 axially parallel conductors (5). • «118398 g Method according to one of the preceding claims, characterized in that more resin is applied to the intermediate layer (9) than to the inner sheath (6) and the outer sheath (7), in relation to the length of the fibrous reinforcement material. A method according to any one of the preceding claims, characterized in that a fibrous reinforcement material is also fitted in the inner shell (6) and the outer shell (7). Arrangement for making a choke comprising 10 means for winding an insulated conductor (5) to form a conductor layer (8) to provide a coil (2), characterized in that the arrangement comprises means for draping the fibrous reinforcing material yarn in an epoxy or polyester resin (13). or for conducting a fibrous reinforcing material yarn immersed in a polyester resin (13) to form an inner sheath (6), an outer sheath (7), and intermediate layers (9) of the winding (2) between the conductor layers (8). An arrangement according to claim 8, characterized in that the fibrous reinforcing material is glass fiber. Arrangement according to Claim 9, characterized in that the fiberglass M · s V is a roving yarn (11). Arrangement according to Claim 10, characterized in that * · •: * · 25 roving yarn (11) is a straight-wound roving yarn. Arrangement according to one of Claims 8 to 11, characterized in that the conductor layer (8) is arranged to be formed from a single conductor (5) or only from axially parallel conductors (5). An arrangement according to any one of claims 8 to 12, characterized in that the arrangement comprises a control means for adjusting the fiber-like reinforcement · ···. defining a resin (13) to be applied to the material such that the guide means is arranged · * to guide the interlayer (9) to the fibrous reinforcement material over its length * | 35 with respect to the length of the fibrous reinforcement material of the inner sheath (6) and the outer sheath (7). 10 118398 Arrangement according to one of Claims 8 to 13, characterized in that the arrangement comprises means for fitting an axially fibrous reinforcing material to the inner jacket (6) and outer jacket (7). 15. A choke having at least one coil (2) having conductor layers (8) and an inner sheath (6) and an outer sheath (7) on the inside, characterized in that the inner sheath (6) and the outer sheath (7) are formed by wounding a fibrous reinforcing yarn wetted with an epoxy or polyester resin (13) and having spacer layers (9) formed between the wiring layers (8) by wounding a fibrous reinforcing yarn wound with an epoxy or polyester resin (13). A choke according to claim 15, characterized in that the fibrous reinforcement material is glass fiber. Inductor according to Claim 16, characterized in that the fiberglass is a roving yarn (11). A choke according to claim 17, characterized in that the roving yarn (11) is a straight-wound roving yarn. A choke according to any one of claims 15 to 18, characterized in that the conductor layer (8) is formed of single conductors (5) or parallel to the axial direction parallel to the earth. management: '! ·! ta (5). • · ♦ A choke according to any one of claims 15 to 19, characterized in that the "intermediate layers (9) have more resin (13) per fiber reinforcing material (13) than the inner (6) and outer (7). A choke according to any one of claims 15 to 20, characterized in that * j '··. Throttle (1) is an air core choke. A choke according to any one of claims 15 to 21, characterized in that the inner sheath (6) and the outer sheath (7) have a fibrous reinforcing material in the axial direction. 5 ··· • · f • · • «« · • · * • § § • • • • • • • • • • • • • • •••••• I * • · # ·· «· ··· • • • * · · · · 999 * · • · 999 ··················••••••••••••••••••••••• 9 9 9 9 12 118398