Title of Invention

INSULATOR UNIT

Abstract

The invention relates to an insulator unit (1) with at least three supporting insulators (2, 3, 4). These supporting insulators each have a column-shaped core made from solid material, a foot section (16, 17, 18) and a head section (20, 21, 22). The foot sections (16, 17, 18) are mechanically rigidly connected to one another and the head sections (20, 21, 22) are mechanically rigidly connected to one another.

Full Text

2006P22544 IN - 1 - Description Insulator unit The invention relates to an insulator unit, which is suitable for example for supporting or mechanically holding electrically live objects, e.g. busbars, isolating switches or smoothing chokes. The use of individual free-standing insulators - so-called supporting insulators - for supporting electrically live objects is generally known. There is currently a demand for energy transmission systems and switchgear systems, which work with very high DC or AC voltages. Here, the development is tending towards so-called UHV-DC switchgear systems, for example (UHV-DC = Ultra High Voltage Direct Current). When very high voltages are used, special requirements are placed on the insulator units. In particular, there are very high requirements with regard to the necessary clearance distances and creepage distances. These requirements cannot be fulfilled with individual free-standing insulators. It can be seen, for example, from the International Standard IEC 62231, First edition 2006-02, "Composite station post insulators for substations with a.c. voltages greater than 1000 V up to 245 kV - Definitions, test methods and acceptance criteria", which is today applicable to solid-core composite insulators, that such individual solid-core composite insulators are only used for voltages up to 245 kV. The invention is based on the object of specifying an insulator unit, which can be used with very high voltages. According to the invention, this object is achieved by an insulator unit with at least three supporting insulators, which each have a column-shaped core made from solid material, a foot 2006P22544 IN - 2 - section and a head section, the foot sections being mechanically rigidly connected to one another and the head sections being mechanically rigidly connected to one another. At the same time, it is particularly advantageous that the at least three supporting insulators (more than three supporting insulators can also be used, for example four, five or six) are mechanically rigidly connected to one another. Advantageously, a very high stiffness and mechanical loading capability of the insulating unit is achieved as a result of the mechanically rigid connection (rigid coupling) of the at least three supporting insulators. This enables this insulator unit to be realized with very large mechanical dimensions, in particular with very large heights. Large clearance distances and long creepage distances can thus be realized, as a result of which such insulator units can also be used for very high voltages. Furthermore, it is advantageous that supporting insulators are used, which each have a column-shaped core made a solid material. Such supporting insulators are also called solid-core supporting insulators. With supporting insulators of this kind, which are available as inexpensive components, such an insulating unit, which with regard to its dimensions has a great height and can be used with very high voltages, can be realized with high stiffness and mechanical loading capability easily and cost effectively. Advantageous embodiments of the insulating unit are specified in the dependent claims. The insulator unit can be designed so that the column-shaped cores of the supporting insulators are arranged parallel to one another. This results in a compact insulator unit with regard to its external dimensions. The insulator unit can be designed so that the foot sections are mechanically rigidly connected to one another by means of a plate to which the foot sections are fixed. 2006P22544 IN - 3 - At the same time, the foot sections can be fixed to the plate by means of screw fasteners. The insulator unit can be designed so that the head sections are mechanically rigidly connected to one another by means of a plate to which the head sections are fixed. At the same time, the head sections can be fixed to the plate by means of screw fasteners. The mechanically rigid connection of the foot sections to one another and of the head sections to one another by means of a plate and by means of screw fasteners advantageously allows the supporting insulators to be mechanically connected to one another easily and cost effectively. Furthermore, advantageously, the screw fasteners can be released again, e.g. in the case of a repair, in order to replace individual supporting insulators of the insulator unit. The insulator unit can be designed so that the plate connecting the head sections (of the at least three supporting insulators) simultaneously connects the foot sections of at least three further supporting insulators rigidly to one another, the three further supporting insulators being aligned in the same direction as the at least three supporting insulators. As the plate connecting the head sections simultaneously connects the foot sections of at least three further supporting insulators rigidly to one another, this insulating unit advantageously has an electrical series circuit in which the at least three supporting insulators, the head sections of which are rigidly connected to one another by means of the plate, are connected electrically in series with the three further supporting insulators, the foot sections of which are rigidly connected to one another by means of the same plate. The withstand voltage of the insulator unit can be still further increased by this 2006P22544 IN - 4 - electrical series circuit, as a result of which the insulator unit can be used with very high voltages. The insulator unit can be designed so that the plate connecting the foot sections (of the at least three supporting insulators) simultaneously connects the head sections of at least three additional supporting insulators rigidly to one another, the three additional supporting insulators being aligned in the same direction as the at least three supporting insulators. As the plate connecting the foot sections of the at least three supporting insulators simultaneously connects the head sections of the at least three additional supporting insulators rigidly to one another, this insulating unit advantageously has an electrical series circuit in which the at least three supporting insulators, which are rigidly connected to one another, are connected in series with the three additional supporting insulators, the head sections of which are rigidly connected to one another by means of the plate. By this means, the withstand voltage of the insulator unit can be still further increased compared with an insulator unit, which consists only of the at least three supporting insulators, which are rigidly connected to one another. The insulator unit can be designed so that the foot section and/or the head section of the supporting insulators is constructed as an end fitting fixed to the core in each case. By means of such an end fitting (for example, made from steel), the supporting insulators can easily be rigidly connected to one another. The insulator unit can be designed so that the cores of the supporting insulators are made of glass fiber reinforced plastic. Supporting insulators with cores made of glass fiber reinforced plastic enable insulator units with high stiffness and large mechanical loading capability to be realized with a 2006P22544 IN - 5 - relatively low mass (compared with other supporting insulators, for example insulators made from porcelain). The insulator unit can be realized so that the cores are each provided with shields. At the same time, the shields can have a water-repellent surface. Such shields can be realized in a particularly easy and cost-effective manner in the case of supporting insulators, which have cores made from glass fiber reinforced plastic. For example, such shields can be shrunk onto the glass fiber reinforced plastic core, as result of which, for example, the production of expensive casting molds for casting a supporting insulator with shields is avoided. Advantageously, the insulator unit can be designed so that it has a height of at least 10 meters and/or that it has a rated withstand voltage of 800 kilovolts for DC. Advantageously, as a result of the mechanically rigid connection of at least three supporting insulators, which have a core made from solid material, an insulating unit can be realized, which is mechanically very stable, in particular which has a high stiffness and loading capability. Advantageously, as a result, it is possible to realize an insulator unit, which has a height of 10 m and above. Advantageously, very high voltages can be insulated by means of such insulator units, e.g. voltages of 800 kV and above. The insulator unit can be designed so that it is arranged to support busbars, smoothing chokes and/or isolating switches. In this way, this insulator unit can be used with advantage in so- called Ultra High Voltage Direct Current high voltage DC transmission systems. The insulator unit can also be realized so that it has a column shape. 2006P22544 IN - 6 - To explain the invention further, an exemplary embodiment of an insulator unit is explained in more detail below with reference to a drawing. The single figure shows an insulator unit 1, which comprises nine supporting insulators 2 to 10. Each of the supporting insulators has a column-shaped (cylindrical) core made from solid material (insulator core), which in the exemplary embodiment is made of glass fiber reinforced plastic (GRP). This core made from solid material is enclosed by a silicone sleeve to which a plurality of shields 11, 12, 13 etc. is fixed. The nine supporting insulators 2 to 10 therefore constitute solid core composite insulators in which a composite material comprising glass fiber reinforced plastic and silicone is present. The shields 11, 12, 13 have a water-repellent (hydrophobic) shield surface. Each of the supporting insulators has a foot section (foot-end flange, foot-end end fitting) and a head section (head-end flange, head-end end fitting). Hence, for example, the supporting insulator 2 has a foot section 16 and a head section 20; the supporting insulator 3 has a foot section 17 and a head section 21, and the supporting insulator 4 has a foot section 18 and a head section 22. These foot sections 16, 17, 18 and/or the head sections 20, 21, 22 can each be constructed as an end fitting, which is fixed to the solid material core. Such an end fitting can, for example, be made of steel and have holes through which screws are placed, which serve to provide a mechanically rigid connection, and by means of which the respective foot and head section can be screwed to plates. The column-shaped cores of the three supporting insulators 2, 3 and 4 are arranged parallel to one another, i.e. the axes of the essentially rotationally symmetrical cores (which also form the axes of the essentially rotationally symmetrical supporting insulators) run parallel to one another. Likewise, the column- 2006P22544 IN - 7 - shaped cores of the three further supporting insulators 5, 6 and 7 are arranged parallel to one another, and the cores of the three additional supporting insulators 8, 9 and 10 are arranged parallel to one another. The axes of all cores point in the same direction. The three supporting insulators 2, 3 and 4 are mechanically rigidly connected to one another. This is achieved in that the three foot sections 16, 17 and 18 are rigidly connected to one another, and that the head sections 20, 21 and 22 are rigidly connected to one another. The mechanically rigid connection of the foot sections to one another is realized in that the foot sections 16, 17 and 18 are fixed to a plate 25 by means of screw fasteners. The head sections 20, 21 and 22 are mechanically rigidly connected to one another in that these head sections are fixed to a plate 27 by means of screw fasteners. At the same time, the plate 27, which connects the head sections 20, 21 and 22 of the supporting insulators 2, 3 and 4, connects foot sections 30, 31 and 32 of the further supporting insulators 5, 6 and 7 rigidly to one another (in the figure, the foot section 31 is hidden by the plate 27) . In the same way, the foot sections 16, 17 and 18 of the supporting insulators 2, 3 and 4 are rigidly connected to one another by means of the plate 25, the plate 25 at the same time connecting head sections 35, 36 and 37 of the three additional supporting insulators 8, 9 and 10 rigidly to one another. Foot sections 38, 39 and 40 of the supporting insulators 8, 9 and 10 are rigidly connected to one another by means of a plate 43. This plate 43 forms a first (bottom) end of the insulator unit 1. Head sections 46, 47 and 48 of the supporting insulators 5, 6 and 7 are rigidly connected to one another by means of a plate 50. This plate 50 forms a second (top) end of the insulator unit 1. 2006P22544 IN - 8 - The insulator unit 1 has a column shape. The insulator unit 1 has a height of ca. 10 m measured from the plate 43 to the plate 50. From an electrical point of view, the supporting insulators 5, 6 and 7 are electrically connected in parallel by the plates 27 and 50. In the same way, the supporting insulators 2, 3 and 4 are electrically connected in parallel by the plates 25 and 27. The supporting insulators 8, 9 and 10 are electrically connected in parallel by the plates 43 and 25. In addition, from an electrical point of view, the insulator unit also has a series circuit: the three supporting insulators 5, 6 and 7, which are electrically connected in parallel, are electrically connected in series with the three supporting insulators 2, 3 and 4 (which are electrically connected in parallel) and with the three supporting insulators 8, 9 and 10 (which are electrically connected in parallel). Due to the mechanically rigid connection of the supporting insulators to one another at the plates 43, 25, 27 and 50, which is realized by means of screw fasteners, an insulator unit is realized, which is very stiff and can be subjected to a high mechanical load. The plates 43 and 50 are so-called "end plates", because they each form an end of the column-shaped insulator unit 1. At the same time, the plates 25 and 27 constitute so-called "intermediate plates", because the supporting insulators are screwed to both sides of the plates 25 and 27, and these plates 25 and 27 are therefore effectively located "between supporting insulators". As a result of these intermediate plates 25 and 27, the strength and mechanical loading capability of the insulator unit is further increased compared with an insulator unit, which has no intermediate plates but only end plates similar to the plates 43 and 50 shown in the figure. In another exemplary embodiment, which is not shown in the figure, an insulator unit can also consist only of the three 2006P22544 IN - 9 - supporting insulators 2, 3 and 4 and the two plates 25 and 27. Such an insulator unit would then only have three supporting insulators and no intermediate plates; the two plates 25 and 27 would then be end plates. Because the supporting insulators 2, 3 and 4 are rigidly screwed to one another, an insulator unit designed in such a way could also be highly loaded mechanically, would be very stiff and would have a high strength. As a result, such an insulator unit could also be realized with a great height, as a result of which a high withstand voltage would likewise be achieved. A further exemplary embodiment, which is not shown in the figure, can be realized so that the foot sections and the head sections of more than three supporting insulators are each mechanically rigidly connected to one another. For example, not only three supporting insulators (namely the supporting insulators 2, 3 and 4) but for example also four, five or six supporting insulators can be arranged between the plates 25 and 27, the foot sections of these four, five or six supporting insulators being fixed by means of screw fasteners to the plate 25 (screwed to the plate 25) and the head sections of these four, five or six supporting insulators being fixed by means of screw fasteners to the plate 27 (screwed to the plate 27). In the same way, for example, four, five or six supporting insulators can also be arranged between the plates 43 and 25 and between the plates 27 and 50 in each case and rigidly connected to one another. An insulator unit with supporting insulators, which have a core made from solid material, in particular a core made from glass fiber reinforced plastic, has a series of advantages. Such supporting insulators are components, which are inexpensive to buy and which - in comparison with porcelain insulators for example - have comparatively low mass. With such supporting insulators, the shield shape and the shield pitch (i.e. the arrangement and distance of the shields) can be chosen 2006P22544 IN - 10 - relatively freely, because the shields can be fixed to the core easily and cost effectively by means of a shrink-on process. In particular, it is not necessary to produce expensive (e.g. customer-specific) casting molds for this purpose. Furthermore, the shields and a silicone sleeve, which encloses the core, can be made from ATH-filled HTV silicone (aluminum-trihydrate- filled high-temperature-vulcanized silicone). On the other hand, the use of such a silicone would not be possible in the case of molded insulators. Furthermore, supporting insulators with solid material core, in particular with cores made from glass fiber reinforced plastic, have the advantage that they are flexible or elastic so that any manufacturing tolerances or inaccuracies that may occur do not lead to problems with the rigid mechanical coupling of the supporting insulators. The flexibility or elasticity prevents breaking of the insulators - this is an advantage compared with porcelain insulators for example. In addition, for the same DC withstand voltage, an insulator unit with about 25% less height is sufficient - compared with an insulator unit made up of porcelain insulators - when shields with a water-repellent surface are used. This is a considerable advantage. Compared with an insulator unit made from porcelain insulators, this gives rise to a significantly lower mass, as a result of which such an insulator unit (with supporting insulators with solid material core) can also be safely used under extreme conditions, for example in the case of earthquakes. Due to the rigid connection of the individual supporting insulators and the resulting high strength, stiffness and mechanical loading capability of the insulator unit, the insulator unit only moves slightly at the top end (at the so- called head, i.e. at the plate 50 of the insulator unit in the exemplary embodiment) even in the case of strong wind, for example, i.e. only a small deflection of the top end of the insulator unit occurs. 2006P22544 IN - 11 - Such insulator units can therefore be used with advantage, for example, in regions at risk of earthquake, with high wind loading, with high connecting forces of a busbar supported by the insulator unit or when only small deflections are- permitted at the head of the insulator unit. As a result, the faulty operation of an isolating switch arranged on the insulator unit or possible deformation of busbars arranged on the insulator unit can be prevented, for example. Because of the use of supporting insulators with solid material core, further advantages of the insulator unit consist in the fact that no potential control problems and boundary layer problems occur inside the insulator core, that only extremely low amounts of moisture can penetrate into the core, and that (because of the non-existence of cavities in the core) no filler media and no devices for monitoring cavities (of a hollow-bodied insulator) are necessary. An insulator unit has been described, which consists of several supporting insulators rigidly connected to one another, which have a core consisting of a solid material. This insulator unit has a high strength, stiffness and mechanical loading capability. As a result of this, this insulator unit can be realized with heights of 10 m and higher, as result of which high withstand voltages (e.g. of 800 kV DC rated voltage and above) can be achieved. In particular, the insulator unit can be used with voltages higher than 245 kV and therefore clearly exceeds the limitations specified in the standard IEC 62231. The insulator unit is suitable for supporting a wide range of electrically live objects, for example for supporting busbars, smoothing chokes and/or isolating switches. As a result, the insulator unit is particularly suitable for use with ultra high direct voltage (UHV DC - ultra high voltage direct current), such as occurs in high voltage direct current transmission systems, for example. This insulator unit enables the clearance 2006P22544 IN - 12 - distance and creepage distance requirements that occur here to be fulfilled by choosing an appropriately large overall height of the insulator unit. 2006P22544 IN - 13 - Patent claims 1. An insulator unit (1) with at least three supporting insulators (2, 3, 4), which each have a column-shaped core made from solid material, a foot section (16, 17, 18) and a head section (20, 21, 22), the foot sections (16, 17, 18) being mechanically rigidly connected to one another and the head sections (20, 21, 22) being mechanically rigidly connected to one another. 2. The insulator unit as claimed in claim 1, characterized in that the column-shaped cores of the supporting insulators (2, 3, 4) are arranged parallel to one another. 3. The insulator unit as claimed in claim 1 or 2, characterized in that the foot sections (16, 17, 18) are mechanically rigidly connected to one another by means of a plate (25) to which the foot sections are fixed. 4. The insulator unit as claimed in claim 3, characterized in that the foot sections (16, 17, 18) are fixed to the plate (25) by means of screw fasteners. 5. The insulator unit as claimed in one of claims 1 to 4, characterized in that the head sections (20, 21, 22) are mechanically rigidly connected to one another by means of a plate (27) to which the head sections are fixed. 6. The insulator unit as claimed in claim 5, characterized in that the head sections (20, 21, 22) are fixed to the plate (27) by means of screw fasteners. 7. The insulator unit as claimed in claim 5 or 6, characterized in that the plate (27) connecting the head sections (20, 21, 22) simultaneously connects the foot sections (30, 31, 32) of at least three further supporting insulators 2006P22544 IN - 14 - (5, 6, 7) rigidly to one another, the three further supporting insulators (5, 6, 7) being aligned in the same direction as the at least three supporting insulators (2, 3, 4). 8. The insulator unit as claimed in one of claims 3 to 7, characterized in that the plate (25) connecting the foot sections (16, 17, 18) simultaneously connects the head sections (35, 36, 37) of at least three additional supporting insulators (8, 9, 10) rigidly to one another, the three additional supporting insulators (8, 9, 10) being aligned in the same direction as the at least three supporting insulators (2, 3, 4) . 9. The insulator unit as claimed in one of the preceding claims, characterized in that the foot section (16, 17, 18, 38) and/or the head section (20, 21, 22, 35) of the supporting insulators (2, 3, 4, 8) is constructed as an end fitting fixed to the core in each case. 10. The insulator unit as claimed in one of the preceding claims, characterized in that the cores are made of glass fiber reinforced plastic. 11. The insulator unit as claimed in one of the preceding claims, characterized in that the cores are each provided with shields (11, 12, 13). 12. The insulator unit as claimed in claim 11, characterized in that the shields (11, 12, 13) have a water-repellent surface. 13. The insulator unit as claimed in one of the preceding claims, characterized in that it has a height of at least 10 meters. 2006P22544 IN - 15 - 14. The insulator unit as claimed in one of the preceding claims, characterized in that it has a rated withstand voltage of 800 kilovolts for DC. 15. The insulator unit as claimed in one of the preceding claims, characterized in that it is arranged to support busbars, smoothing chokes and/or isolating switches. 16. The insulator unit as claimed in one of the preceding claims, characterized in that it has a column shape. The invention relates to an insulator unit (1) with at least three supporting insulators (2, 3, 4). These supporting insulators each have a column-shaped core made from solid material, a foot section (16, 17, 18) and a head section (20, 21, 22). The foot sections (16, 17, 18) are mechanically rigidly connected to one another and the head sections (20, 21, 22) are mechanically rigidly connected to one another.

Documents:

01489-kol-2007-abstract.pdf

01489-kol-2007-claims.pdf

01489-kol-2007-correspondence others 1.1.pdf

01489-kol-2007-correspondence others.pdf

01489-kol-2007-description complete.pdf

01489-kol-2007-drawings.pdf

01489-kol-2007-form 1.pdf

01489-kol-2007-form 2.pdf

01489-kol-2007-form 3.pdf

01489-kol-2007-form 5.pdf

01489-kol-2007-gpa.pdf

01489-kol-2007-others.pdf

01489-kol-2007-priority document.pdf

01489-kol-2007-translated copy of priority document.pdf

1489-KOL-2007-(02-11-2012)-ABSTRACT.pdf

1489-KOL-2007-(02-11-2012)-ANNEXURE TO FORM 3.pdf

1489-KOL-2007-(02-11-2012)-CLAIMS.pdf

1489-KOL-2007-(02-11-2012)-CORRESPONDENCE.pdf

1489-KOL-2007-(02-11-2012)-FORM-1.pdf

1489-KOL-2007-(02-11-2012)-FORM-2.pdf

1489-KOL-2007-(02-11-2012)-PETITION UNDER RULE 137.pdf

1489-KOL-2007-CORRESPONDENCE OTHERS 1.2.pdf

1489-KOL-2007-FORM 18.pdf

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