EP2180485B1 - High-voltage bushing - Google Patents

High-voltage bushing Download PDF

Info

Publication number
EP2180485B1
EP2180485B1 EP08460041A EP08460041A EP2180485B1 EP 2180485 B1 EP2180485 B1 EP 2180485B1 EP 08460041 A EP08460041 A EP 08460041A EP 08460041 A EP08460041 A EP 08460041A EP 2180485 B1 EP2180485 B1 EP 2180485B1
Authority
EP
European Patent Office
Prior art keywords
layer
current
collecting member
bushing
field
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP08460041A
Other languages
German (de)
French (fr)
Other versions
EP2180485A1 (en
Inventor
Jan Czyzewski
Jens Rocks
Norbert Koch
Kenneth Johannsson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Research Ltd Switzerland
ABB Research Ltd Sweden
Original Assignee
ABB Research Ltd Switzerland
ABB Research Ltd Sweden
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by ABB Research Ltd Switzerland, ABB Research Ltd Sweden filed Critical ABB Research Ltd Switzerland
Priority to EP08460041A priority Critical patent/EP2180485B1/en
Priority to AT08460041T priority patent/ATE509353T1/en
Publication of EP2180485A1 publication Critical patent/EP2180485A1/en
Application granted granted Critical
Publication of EP2180485B1 publication Critical patent/EP2180485B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01BCABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B17/00Insulators or insulating bodies characterised by their form
    • H01B17/26Lead-in insulators; Lead-through insulators
    • H01B17/28Capacitor type

Definitions

  • the subject of the invention is a high-voltage bushing applicable in electric power engineering.
  • a typical condenser bushing for medium- or high-voltage applications that is, from 24kV to 800kV and above, comprises a condenser core with a number of concentric electrically conducting field-grading layers of cylindrical shape arranged around the central conductor so as to form a capacitive divider uniformly distributing the voltage among the field-grading layers.
  • the electric field generated by the high voltage is also uniformly distributed, both inside the condenser core in the radial direction, and outside, close to the outer surface of the bushing, along its axis.
  • Field-grading layers of the condenser core are usually made of metal foil. Bushings using such field-grading layers are known, e.g. from the following patent descriptions: US 3875327 , US 4 362 897 , US 4 338 487 , US 4 387 266 , US 4 500 745 and GB 1 125 964 .
  • Field-grading layers made of metal foil are characterized by very low surface resistivity, typically 1-3m ⁇ per square.
  • the geometrical arrangement of the field-grading layers of such low resistivity in the condenser core constitutes a number of interconnected capacitance and inductance elements prone to resonant high-frequency oscillations of large quality factor. Such oscillations are triggered by electric impulses of high frequency and lead to local occurrence of high electric field in the condenser core, with a risk of insulation damage.
  • Field-grading layers used in a bushing known from patent description WO2006/001724 are made on the basis of paper, fabric or nonwoven cloth and contain conducting particles suspended in it and forming a percolating network, electrically conducting in the layer plane.
  • the particles can be e.g. carbon nanotubes, carbon nanofibers, metallic microfibers.
  • Such percolative structures are also characterized by electric resistivity higher then that of metals.
  • the innermost field-grading layer of the condenser core of a bushing is electrically connected to the conductor of the bushing.
  • the outermost, and/or one of the other outer field-grading layers are electrically connected to the ground potential. Connection to the ground potential goes typically via the metallic flange which serves to mechanically fix the bushing to the grounded equipment.
  • At least one of the connections of the outer field-grading layers is arranged in a socket, so that it can be disconnected from the grounded flange and connected to a testing device to perform electrical tests on the bushing.
  • the socket is short circuited by a conductive plug.
  • the socket is known as test- or measurement tap (when connected to the outermost field-grading layer) or voltage- or potential tap (when connected one of the other outer field-grading layers).
  • the connections of the inner- and the outer field-grading layers carry a relatively small capacitive current flowing through the electric capacitance of the condenser core.
  • a pulse of substantially higher current is carried by the connection.
  • the current is being distributed from the connection into the field-grading layer plane and the highest density of the surface current in the field-grading layer occurs close to the point at which the electrical connection is attached to the layer. For a circular connection point, the current density is equal to the total current divided by the circumference of the connection spot.
  • a bushing with field-grading layers made of material of limited current carrying capacity, and, in the same time, with improved current withstand of the connection during a surge is known from a patent description GB 539 587 .
  • the bushing comprises an additional surge-draining layer, to which the external connection is applied, made of a stout conducting material of a high current carrying capacity.
  • the surge-draining layer is electrically connected to the outermost field-grading layer by one or more conductive connections.
  • the capacitive current flows through the conductive connection.
  • a part of the high frequency current takes the other path distributed over the whole or the major part of the surface of the field-grading layer and the impedance of that path is such that the substantial part of the high-frequency current takes this distributed path.
  • the distributed path of the current is formed by the substantial capacitance between the field-grading layer and the surge-draining layer.
  • the resistance of the surge-draining layer is very low, compared to the impedance related to that capacitance. Effectively, during the surge, the current path goes from the connection, along the surface of the surge-draining layer and farther, through the capacitance into the field-grading layer in the direction perpendicular to both layers.
  • the problem to be solved is to provide an electric connection to a field grading layer of increased resistivity, made in such a way that a substantial part of the high-frequency surge current flows along the surface of that field-grading layer, thus giving the effect of damping the high-frequency oscillations but in the same time the surface current density in that layer is limited so that the layer is not damaged during the surge.
  • the essence of the high-voltage bushing according to the invention comprising a condenser core and electrically conducting field-grading layers which are arranged coaxially around the central conductor and are embedded in the insulating material of the condenser core, while an electric connection is provided, by means of a current-collecting member, to at least one of the field-grading layers, and this layer is made in form of a thin metal layer deposited on an electrically insulating substrate layer or in form of a percolating network of conducting particles suspended in a layer of electrically insulating material is that the current-collecting member is located on the surface of the layer to which the electric connection is provided and covers a part of the area of that layer.
  • the surface resistivity of the current-collecting member is many times smaller than the surface resistivity of the layer to which the electric connection is provided.
  • the current-collecting member is shaped so that the length of the contour line of its circumference is greater than the length of the shorter side of the layer on the surface of which the current-collecting member is located.
  • the length of the contour line of the circumference of the current-collecting member is selected so that during the impulse test required for the bushing, the root-mean-square average of the surface density of the current flowing across the surface of the layer on which the current-collecting member is located, close to the contour line of the circumference of the current-collecting member, is smaller than the root-mean-square average of the withstand current density for that layer exposed to a pulse of a shape and duration similar to the shape and duration of the current flowing through the electric connection which drains the current during the impulse test of the bushing.
  • the layer on whose surface the current-collecting member is located has surface resistivity greater than 100m ⁇ per square.
  • the current-collecting member has an elongated shape, and it is located on the surface of the field grading layer longitudinally with respect to the direction of the longitudinal axis of the bushing.
  • the current collecting member is positioned close to the symmetry axis of the field-grading layer.
  • the current-collecting member has an elongated shape, and it is located on the surface of the field grading layer perpendicularly with respect to the direction of the longitudinal axis of the bushing.
  • the current-collecting member has a shape similar to a geometric figure consisting of many elongated conducting elements located parallel to one another and connected crosswise by means of another elongated conducting element.
  • the current collecting member is made of metal foil.
  • the current collecting member is made of a braid or a woven or unwoven fabric containing metal wires, fibers or metal foil strips.
  • the current collecting member is electrically connected with the field grading layer using electrically conducting adhesive or electrically conductive paint.
  • a high-voltage instrument transformer comprising a bushing according to the invention.
  • the bushing according to the invention is highly resistant to high-frequency voltage oscillations or impulses since the high frequency oscillations are damped by the electric resistance of the field-grading layer to which the connection is provided.
  • the current density in the field grading layer is limited so that the bushing is not prone to failures due to a pulse of high current occurring during surge condition.
  • fig. 1 shows schematically the longitudinal section of the high-voltage bushing
  • fig. 2 the same bushing in cross-section along the line A-A
  • fig. 3 the unwound outer field-grading layer together with the current-collecting member in the first embodiment of the invention
  • fig. 4 the unwound outer field-grading layer together with the current-collecting member in the second embodiment of the invention
  • fig. 5a the unwound outer field-grading layer together with the current-collecting member in the third embodiment of the invention
  • fig. 5b the field-grading layer of fig. 5a with the relevant surface areas indicated
  • the high-voltage bushing comprises a condenser core 1 which is arranged around a central cylindrical conductor 2.
  • the condenser core 1 is placed inside a standard insulating casing intended for high-voltage bushings, which is not shown in the drawing.
  • the condenser core 1 is comprised of many field-grading layers 3 which are placed cylindrically, coaxially around the central cylindrical conductor 2 and are embedded in insulating material 4 of the condenser core 1.
  • an external electric connection 6 which connects the layer 3a with an external conducting flange 7 by means of which the bushing is fixed to the earthed wall of the electric equipment, not shown in the drawing.
  • the electric connection 6 can be also connected to one of the other layers 3, typically layers located nearer the flange 7, which is not shown in the drawing.
  • the connection 6 can also be connected to the layer 3 located closest to the central conductor 2, and the connection 6 is then connected to the central conductor 2, which is not shown in the drawing either.
  • connection 6 connected to one of the layers 3 located nearer the flange 7 or to the outer layer 3a can be also connected to a test- or voltage tap in form of the contact of a socket located in the flange 7, which is not shown in the drawing.
  • a socket located in the flange 7, which is not shown in the drawing.
  • Such socket makes it possible to connect measuring instruments to the appropriate layer 3 or 3a, or, by short-circuiting the socket contact with the flange 7, allows the earthing of the given layer 3 or 3a.
  • the field-grading layer 3a of the exemplary embodiment of the invention is made of paper filled with a percolating network of metallic fibres and its surface resistance is 10 ⁇ - 20 ⁇ per square.
  • the field-grading layer 3a is made as a metallic film applied on an electrically insulating substrate layer made of insulating paper and its surface resistance is 5 ⁇ - 15 ⁇ per square.
  • the current-collecting member 5 is placed on the outermost layer 3a and is in electric contact with it over the whole area of the current-collecting member 5.
  • the current-collecting member 5 has a shape similar to a rectangle with rounded corners and in the first embodiment of the invention it is located on the layer 3a in such way that the longer sides of the rectangle are located parallel to the direction of the longitudinal axis of the bushing , marked by an arrow 8 in the drawing.
  • the current-collecting member 5 is located near the axis of symmetry of the layer 3a.
  • the current-collecting member 5 is made as a flat braid consisting of copper wires, whose surface resistance is at least 1000 times less than the surface resistance of the field-grading layer 3a.
  • the contour line of the circumference "L" of the current-collecting member 5 is a line, substantially perpendicularly to which the current flow distribution takes place in plane of the layer 3a from the member 5 to the layer 3a.
  • the current is supplied to the current-collecting member 5 through the connection 6.
  • the length of the contour line of the circumference "L” is approximately twice longer than the length of the shorter side of the layer 3a.
  • the current-collecting member 5 which is located on the outermost layer 3a, has a shape similar to a rectangle with rounded corners and it is located on the layer 3a in such way that the longer sides of the rectangle are located perpendicularly to the direction of the longitudinal axis of the bushing, marked by a bi-directional arrow 8 in the drawing.
  • the current-collecting member 5 is made as a flat braid, consisting of copper wires, whose surface resistance is at least 1000 times less than the surface resistance of the field-grading layer 3a.
  • the contour line of the circumference "L" of the current-collecting member is a line, substantially perpendicularly to which the current flow distribution takes place in plane of the layer 3a from the current-collecting member 5 to the layer 3a.
  • the current is supplied to the member 5 through the connection 6.
  • the length of the contour line of the circumference "L” is approximately 4 times longer than the length of the shorter side of the layer 3a.
  • the current-collecting member 5, which is located on the outermost layer 3a has a shape similar to a geometric figure comprised of many elongated, preferably rectangular conducting elements 9 with rounded corners, located parallel to one another and interconnected crosswise by means of another rectangular conducting element 10 with rounded corners, whose longer sides are located perpendicularly to the direction of the longitudinal axis of the bushing, marked with a bi-directional arrow 8 in the drawing.
  • the conducting elements 9 and 10 are made as a flat braid of copper wires, whose surface resistance is at least 1000 times less than the surface resistance of the field-grading layer 3a.
  • the contour line of the circumference "L" of the current-collecting electrode is a line, substantially perpendicularly to which the current flow distribution takes place in plane of the layer 3a from the current-collecting member 5 to the layer 3a.
  • Current is supplied to the conducting element 10 of the current-collecting member 5 through the connection 6.
  • the length of the contour line of the circumference "L” is approximately 10 times longer than the length of the shorter side of the layer 3a.
  • the length of the contour line "L" of the circumference of the current-collecting member 5 is so selected that during the impulse test required for the bushing, the root-mean-square average of the surface density of the current flowing across the surface of the layer 3a near the contour line "L" is smaller than the root-mean-square average of the withstand current density for the layer 3a exposed to a pulse of a form and duration similar to the form and duration of current flowing through the connection 6 during the impulse test of the bushing.
  • the bushing undergoes a chopped lightning impulse test.
  • An exemplary waveform of the surge current I CLI flowing through the connection 6 during such test is shown in fig. 6 .
  • the surge current I CLI runs through the connection 6 to the current-collecting member 5. From there, a part I CC of the surge current I CLI , flows to the layer 3a in the direction perpendicular to its surface and farther, capacitively to the other field-grading layers 3.
  • the other part of the surge current, I NC . flows into the part of layer 3a not covered by the current-collecting member 5 in the direction parallel to its surface and substantially perpendicular to the contour line "L" ( fig.3 ) of the circumference of the current-collecting member 5. This part of the surge current flows farther from the layer 3a capacitively to the successive field-grading layers 3 as well.
  • the capacitive impedance is the main part of the high-frequency impedance of the circuit
  • the ratio of the values of the currents I CC and I NC corresponds to the ratio of the respective capacitances, which in turn are proportional to the surface area Scc of the current-collecting member 5 and the surface area S NC of the layer 3a not covered by the current-collecting member 5, respectively, with the exception of the surface area of the zone 11 on which fragments of the wound layer 3a overlap.
  • the length L is selected so that the root-mean-square average current density ⁇ L does not exceed the average withstand current density for the material of which the layer 3a embedded in insulating material used in the bushing is made.
  • the root-mean-square average withstand current density for the material of the layer 3a is defined for a pulse of a form similar to the form of the pulse I CLI , or the form of its envelope indicated by a dashed line, both indicated in fig. 6 and of duration identical with or longer than the duration of the pulse I CLI .
  • the material of the layer 3a is not damaged during the applied impulse test.
  • a large part I NC of surge current I CLI flows across the surface of the layer 3a and the electric resistance of this surface contributes to the attenuation of the high-frequency oscillations.
  • the above described division of the surge current I CLI into the currents I CC and I NC applies to a case where the connection 6 is provided to the outer field-grading layer 3a.
  • the division of the surge current takes place according to the relation between other corresponding surfaces.
  • the division of currents takes place in proportion to the corresponding surface areas of the next, neighbouring it on the outside, field-grading layer.
  • the current-collecting member 5 or its elements 9 and 10 can be alternatively made of metallic foil which is located on the surface of the layer 3a.
  • the current-collecting member 5 or its elements 9 and 10 can be alternatively made as a braid, or a woven or unwoven fabric containing metal wires, fibres or metal foil strips.
  • the current-collecting member 5 can be alternatively electrically connected with the field-grading layer 3a by means of a layer of conductive adhesive and/or paint, which is not shown in the drawing.
  • the bushing according to the invention is an element of a high-voltage instrument transformer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Insulators (AREA)

Abstract

The subject of the invention is a high-voltage bushing applicable in electric power engineering. The high-voltage bushing comprises a condenser core (1) and electrically conducting field-grading layers (3) which are arranged coaxially around the central conductor (2) and are embedded in insulating material (4) of the condenser core (1). An electric connection (6) is provided to at least one layer (3a) of the field-grading layers (3) by means of a current-collecting member (5). The layer (3a) is made in form of thin metal film deposited on an electrically insulating substrate layer or in form of a percolating network of conductive particles suspended in a layer of electrically insulating material, and the current-collecting member (5) is positioned on the surface of the layer (3a) and it covers a part of the surface area of the layer (3a) and has the surface resistivity many times smaller than the surface resistivity of the layer (3a). The current-collecting member (5) is shaped so that the length of the contour line of its circumference (L) is greater than the length of the shorter side of the layer (3a).

Description

  • The subject of the invention is a high-voltage bushing applicable in electric power engineering.
  • Bushings are devices used to lead a conductor under voltage through an opening in a wall or equipment at ground (earth) potential. A typical condenser bushing for medium- or high-voltage applications, that is, from 24kV to 800kV and above, comprises a condenser core with a number of concentric electrically conducting field-grading layers of cylindrical shape arranged around the central conductor so as to form a capacitive divider uniformly distributing the voltage among the field-grading layers. As a result, the electric field generated by the high voltage is also uniformly distributed, both inside the condenser core in the radial direction, and outside, close to the outer surface of the bushing, along its axis.
  • Field-grading layers of the condenser core are usually made of metal foil. Bushings using such field-grading layers are known, e.g. from the following patent descriptions: US 3875327 , US 4 362 897 , US 4 338 487 , US 4 387 266 , US 4 500 745 and GB 1 125 964 .
  • Field-grading layers made of metal foil are characterized by very low surface resistivity, typically 1-3mΩ per square. The geometrical arrangement of the field-grading layers of such low resistivity in the condenser core constitutes a number of interconnected capacitance and inductance elements prone to resonant high-frequency oscillations of large quality factor. Such oscillations are triggered by electric impulses of high frequency and lead to local occurrence of high electric field in the condenser core, with a risk of insulation damage.
  • One of the methods to avoid such oscillations is application of field-grading layers of increased surface resistivity. Increased resistivity of the field-grading layers leads to reducing the quality factor of the oscillation circuits. In consequence, the amplitude of the oscillations is reduced and there is less risk of insulation damage. Numerous ways are known of manufacturing field-grading layers of increased electric resistivity.
  • From a Japanese patent description JP 01283716 there is known a cast bushing in which the field-grading layers are made of fabric or nonwoven cloth having a conductive layer on its surface, e.g. in form of conductive paint. Typical resistivity of conductive paints is much larger than that of metal.
  • Field-grading layers used in a bushing known from patent description WO2006/001724 are made on the basis of paper, fabric or nonwoven cloth and contain conducting particles suspended in it and forming a percolating network, electrically conducting in the layer plane. The particles can be e.g. carbon nanotubes, carbon nanofibers, metallic microfibers. Such percolative structures are also characterized by electric resistivity higher then that of metals.
  • Another way of increasing the resistivity of the field-grading layers is using a very thin layer of metal, for example deposited on insulating material. From the unpublished patent application EP06460047 there is known an insulating structure with field-grading layers, applicable in high-voltage bushings, in which the field-grading layers are made in form of an insulating substrate layer coated with a very thin metal layer.
  • The innermost field-grading layer of the condenser core of a bushing is electrically connected to the conductor of the bushing. The outermost, and/or one of the other outer field-grading layers are electrically connected to the ground potential. Connection to the ground potential goes typically via the metallic flange which serves to mechanically fix the bushing to the grounded equipment.
  • In most of the condenser bushing types, at least one of the connections of the outer field-grading layers is arranged in a socket, so that it can be disconnected from the grounded flange and connected to a testing device to perform electrical tests on the bushing. During normal operation, the socket is short circuited by a conductive plug. Depending on the function, the socket is known as test- or measurement tap (when connected to the outermost field-grading layer) or voltage- or potential tap (when connected one of the other outer field-grading layers).
  • During normal operation, the connections of the inner- and the outer field-grading layers carry a relatively small capacitive current flowing through the electric capacitance of the condenser core. In surge conditions caused by a lightning impulse, operation of a surge arrester or switching, a pulse of substantially higher current is carried by the connection. A similar situation occurs during impulse testing of a bushing performed in laboratory conditions. During the pulse, the current is being distributed from the connection into the field-grading layer plane and the highest density of the surface current in the field-grading layer occurs close to the point at which the electrical connection is attached to the layer. For a circular connection point, the current density is equal to the total current divided by the circumference of the connection spot. For a typical connection used with field grading layers made of metal foil, this circumference is very small. For example, for a soldering connection, the circumference of the contact point (a drop of solder) is typically of the order of 5-15mm, and the local surface current density in the layer can be very large, much larger than the current densities in all the other layers, to which the connections are not provided. Field-grading layers of increased surface resistivity have smaller ability to conduct large electric current than the conventionally used metal foils. Thus, the application of the field-grading layers of increased resistivity, as the layers to which the connections are attached requires a dedicated, new solution.
  • A bushing with field-grading layers made of material of limited current carrying capacity, and, in the same time, with improved current withstand of the connection during a surge, is known from a patent description GB 539 587 . The bushing comprises an additional surge-draining layer, to which the external connection is applied, made of a stout conducting material of a high current carrying capacity. The surge-draining layer is electrically connected to the outermost field-grading layer by one or more conductive connections. During normal operation, the capacitive current flows through the conductive connection. In a surge condition, a part of the high frequency current takes the other path distributed over the whole or the major part of the surface of the field-grading layer and the impedance of that path is such that the substantial part of the high-frequency current takes this distributed path.
  • In that technical solution, in a surge condition, the distributed path of the current is formed by the substantial capacitance between the field-grading layer and the surge-draining layer. The resistance of the surge-draining layer is very low, compared to the impedance related to that capacitance. Effectively, during the surge, the current path goes from the connection, along the surface of the surge-draining layer and farther, through the capacitance into the field-grading layer in the direction perpendicular to both layers. Thus, virtually no current flows along the surface of the field-grading layer and even when the layer of increased resistivity is applied, there is no effect of damping of high-frequency oscillations by the resistance of that layer.
  • The problem to be solved is to provide an electric connection to a field grading layer of increased resistivity, made in such a way that a substantial part of the high-frequency surge current flows along the surface of that field-grading layer, thus giving the effect of damping the high-frequency oscillations but in the same time the surface current density in that layer is limited so that the layer is not damaged during the surge.
  • The essence of the high-voltage bushing according to the invention, comprising a condenser core and electrically conducting field-grading layers which are arranged coaxially around the central conductor and are embedded in the insulating material of the condenser core, while an electric connection is provided, by means of a current-collecting member, to at least one of the field-grading layers, and this layer is made in form of a thin metal layer deposited on an electrically insulating substrate layer or in form of a percolating network of conducting particles suspended in a layer of electrically insulating material is that the current-collecting member is located on the surface of the layer to which the electric connection is provided and covers a part of the area of that layer. The surface resistivity of the current-collecting member is many times smaller than the surface resistivity of the layer to which the electric connection is provided. The current-collecting member is shaped so that the length of the contour line of its circumference is greater than the length of the shorter side of the layer on the surface of which the current-collecting member is located.
  • Preferably, the length of the contour line of the circumference of the current-collecting member is selected so that during the impulse test required for the bushing, the root-mean-square average of the surface density of the current flowing across the surface of the layer on which the current-collecting member is located, close to the contour line of the circumference of the current-collecting member, is smaller than the root-mean-square average of the withstand current density for that layer exposed to a pulse of a shape and duration similar to the shape and duration of the current flowing through the electric connection which drains the current during the impulse test of the bushing.
  • Preferably, the layer on whose surface the current-collecting member is located has surface resistivity greater than 100mΩ per square.
  • Preferably, the current-collecting member has an elongated shape, and it is located on the surface of the field grading layer longitudinally with respect to the direction of the longitudinal axis of the bushing.
  • Preferably, the current collecting member is positioned close to the symmetry axis of the field-grading layer.
  • Alternatively, the current-collecting member has an elongated shape, and it is located on the surface of the field grading layer perpendicularly with respect to the direction of the longitudinal axis of the bushing.
  • Preferably, the current-collecting member has a shape similar to a geometric figure consisting of many elongated conducting elements located parallel to one another and connected crosswise by means of another elongated conducting element.
  • Preferably, the current collecting member is made of metal foil.
  • Alternatively, the current collecting member is made of a braid or a woven or unwoven fabric containing metal wires, fibers or metal foil strips.
  • Preferably, the current collecting member is electrically connected with the field grading layer using electrically conducting adhesive or electrically conductive paint.
  • A high-voltage instrument transformer comprising a bushing according to the invention.
  • The bushing according to the invention is highly resistant to high-frequency voltage oscillations or impulses since the high frequency oscillations are damped by the electric resistance of the field-grading layer to which the connection is provided. In the same time, the current density in the field grading layer is limited so that the bushing is not prone to failures due to a pulse of high current occurring during surge condition.
  • The invention is presented as an embodiment in the drawing where fig. 1 shows schematically the longitudinal section of the high-voltage bushing, fig. 2 - the same bushing in cross-section along the line A-A, fig. 3 - the unwound outer field-grading layer together with the current-collecting member in the first embodiment of the invention, fig. 4 - the unwound outer field-grading layer together with the current-collecting member in the second embodiment of the invention, fig. 5a - the unwound outer field-grading layer together with the current-collecting member in the third embodiment of the invention, fig. 5b - the field-grading layer of fig. 5a with the relevant surface areas indicated, fig. 6 - an example of the waveform of the current flowing through the connection of the field-grading layer during the impulse test, and fig. 7 - the outer field-grading layers, in cross-section along the line A-A, in the first embodiment of the invention with the distribution of the current from the connection to the field-grading layers indicated in the drawing.
  • The high-voltage bushing according to the invention comprises a condenser core 1 which is arranged around a central cylindrical conductor 2. The condenser core 1 is placed inside a standard insulating casing intended for high-voltage bushings, which is not shown in the drawing. The condenser core 1 is comprised of many field-grading layers 3 which are placed cylindrically, coaxially around the central cylindrical conductor 2 and are embedded in insulating material 4 of the condenser core 1. To one of the layers 3, for example the outermost layer 3a, there is connected, by means of a current-collecting member 5, an external electric connection 6 which connects the layer 3a with an external conducting flange 7 by means of which the bushing is fixed to the earthed wall of the electric equipment, not shown in the drawing. The electric connection 6 can be also connected to one of the other layers 3, typically layers located nearer the flange 7, which is not shown in the drawing. The connection 6 can also be connected to the layer 3 located closest to the central conductor 2, and the connection 6 is then connected to the central conductor 2, which is not shown in the drawing either. The connection 6 connected to one of the layers 3 located nearer the flange 7 or to the outer layer 3a can be also connected to a test- or voltage tap in form of the contact of a socket located in the flange 7, which is not shown in the drawing. Such socket makes it possible to connect measuring instruments to the appropriate layer 3 or 3a, or, by short-circuiting the socket contact with the flange 7, allows the earthing of the given layer 3 or 3a. The field-grading layer 3a of the exemplary embodiment of the invention is made of paper filled with a percolating network of metallic fibres and its surface resistance is 10Ω - 20Ω per square. Alternatively, the field-grading layer 3a is made as a metallic film applied on an electrically insulating substrate layer made of insulating paper and its surface resistance is 5Ω - 15Ω per square. The current-collecting member 5 is placed on the outermost layer 3a and is in electric contact with it over the whole area of the current-collecting member 5. The current-collecting member 5 has a shape similar to a rectangle with rounded corners and in the first embodiment of the invention it is located on the layer 3a in such way that the longer sides of the rectangle are located parallel to the direction of the longitudinal axis of the bushing , marked by an arrow 8 in the drawing. The current-collecting member 5 is located near the axis of symmetry of the layer 3a. The current-collecting member 5 is made as a flat braid consisting of copper wires, whose surface resistance is at least 1000 times less than the surface resistance of the field-grading layer 3a. The contour line of the circumference "L" of the current-collecting member 5 is a line, substantially perpendicularly to which the current flow distribution takes place in plane of the layer 3a from the member 5 to the layer 3a. The current is supplied to the current-collecting member 5 through the connection 6. The length of the contour line of the circumference "L" is approximately twice longer than the length of the shorter side of the layer 3a.
  • In the second embodiment of the invention, the current-collecting member 5, which is located on the outermost layer 3a, has a shape similar to a rectangle with rounded corners and it is located on the layer 3a in such way that the longer sides of the rectangle are located perpendicularly to the direction of the longitudinal axis of the bushing, marked by a bi-directional arrow 8 in the drawing. The current-collecting member 5 is made as a flat braid, consisting of copper wires, whose surface resistance is at least 1000 times less than the surface resistance of the field-grading layer 3a. The contour line of the circumference "L" of the current-collecting member is a line, substantially perpendicularly to which the current flow distribution takes place in plane of the layer 3a from the current-collecting member 5 to the layer 3a. The current is supplied to the member 5 through the connection 6. The length of the contour line of the circumference "L" is approximately 4 times longer than the length of the shorter side of the layer 3a.
  • In the third embodiment of the invention, the current-collecting member 5, which is located on the outermost layer 3a has a shape similar to a geometric figure comprised of many elongated, preferably rectangular conducting elements 9 with rounded corners, located parallel to one another and interconnected crosswise by means of another rectangular conducting element 10 with rounded corners, whose longer sides are located perpendicularly to the direction of the longitudinal axis of the bushing, marked with a bi-directional arrow 8 in the drawing. The conducting elements 9 and 10 are made as a flat braid of copper wires, whose surface resistance is at least 1000 times less than the surface resistance of the field-grading layer 3a. The contour line of the circumference "L" of the current-collecting electrode is a line, substantially perpendicularly to which the current flow distribution takes place in plane of the layer 3a from the current-collecting member 5 to the layer 3a. Current is supplied to the conducting element 10 of the current-collecting member 5 through the connection 6. The length of the contour line of the circumference "L" is approximately 10 times longer than the length of the shorter side of the layer 3a.
  • In all the embodiments, the length of the contour line "L" of the circumference of the current-collecting member 5 is so selected that during the impulse test required for the bushing, the root-mean-square average of the surface density of the current flowing across the surface of the layer 3a near the contour line "L" is smaller than the root-mean-square average of the withstand current density for the layer 3a exposed to a pulse of a form and duration similar to the form and duration of current flowing through the connection 6 during the impulse test of the bushing.
  • In the embodiment, the bushing undergoes a chopped lightning impulse test. An exemplary waveform of the surge current I CLI flowing through the connection 6 during such test is shown in fig. 6.
  • As shown in fig. 7, the surge current I CLI runs through the connection 6 to the current-collecting member 5. From there, a part I CC of the surge current I CLI, flows to the layer 3a in the direction perpendicular to its surface and farther, capacitively to the other field-grading layers 3. The other part of the surge current, I NC. flows into the part of layer 3a not covered by the current-collecting member 5 in the direction parallel to its surface and substantially perpendicular to the contour line "L" (fig.3) of the circumference of the current-collecting member 5. This part of the surge current flows farther from the layer 3a capacitively to the successive field-grading layers 3 as well. Therefore, since the capacitive impedance is the main part of the high-frequency impedance of the circuit, the ratio of the values of the currents I CC and I NC corresponds to the ratio of the respective capacitances, which in turn are proportional to the surface area Scc of the current-collecting member 5 and the surface area SNC of the layer 3a not covered by the current-collecting member 5, respectively, with the exception of the surface area of the zone 11 on which fragments of the wound layer 3a overlap. Hence the other part of the surge current is: I NC = I CLI S NC S 3 a ,
    Figure imgb0001
    where S3a is the surface area of the layer 3a except for the surface area of the zone 11 on which fragments of the rolled up layer 3a overlap.
  • The surface density ρL of the current flowing across the surface of the layer 3a, near the contour line "L", is, on average, I NC/L, where L is the length of the contour line "L", hence ρ L = I CLI S NC L S 3 a .
    Figure imgb0002
  • Using the above equation, the length L is selected so that the root-mean-square average current density ρL does not exceed the average withstand current density for the material of which the layer 3a embedded in insulating material used in the bushing is made. The root-mean-square average withstand current density for the material of the layer 3a is defined for a pulse of a form similar to the form of the pulse ICLI, or the form of its envelope indicated by a dashed line, both indicated in fig. 6 and of duration identical with or longer than the duration of the pulse ICLI.
  • For such selection of the contour line L length, the material of the layer 3a is not damaged during the applied impulse test. At the same time, a large part INC of surge current ICLI flows across the surface of the layer 3a and the electric resistance of this surface contributes to the attenuation of the high-frequency oscillations.
  • The above described division of the surge current I CLI into the currents I CC and I NC applies to a case where the connection 6 is provided to the outer field-grading layer 3a. For a case where the connection 6 is provided to another layer, the division of the surge current takes place according to the relation between other corresponding surfaces. In particular, for the innermost layer closest to the central conductor 2, the division of currents takes place in proportion to the corresponding surface areas of the next, neighbouring it on the outside, field-grading layer.
  • In all embodiments of the invention, the current-collecting member 5 or its elements 9 and 10 can be alternatively made of metallic foil which is located on the surface of the layer 3a.
  • In all embodiments of the invention, the current-collecting member 5 or its elements 9 and 10 can be alternatively made as a braid, or a woven or unwoven fabric containing metal wires, fibres or metal foil strips.
  • In all embodiments of the invention, the current-collecting member 5 can be alternatively electrically connected with the field-grading layer 3a by means of a layer of conductive adhesive and/or paint, which is not shown in the drawing.
  • Alternatively, the bushing according to the invention is an element of a high-voltage instrument transformer.

Claims (11)

  1. A high-voltage bushing comprising a condenser core (1) and electrically conductive field-grading layers (3) which are arranged coaxially around the central conductor (2) and are embedded in insulating material (4) of the condenser core (1), while an electric connection (6) is provided to at least one layer (3a) of the field-grading layers (3) by means of a current-collecting member (5), and the layer (3a) is made in form of a thin metal layer deposited on an electrically insulating substrate layer or in form of a percolating network of conductive particles suspended in a layer of electrically insulating material, characterised in that the current-collecting member (5) is located on the surface of the layer (3a) and it covers a part of the surface area of the layer (3a) and it has a surface resistivity many times smaller than the surface resistivity of the layer (3a) and it is shaped so that the length of the contour line of its circumference (L) is greater than the length of the shorter side of the layer (3a).
  2. A bushing according to claim1, characterised in that the length of the contour line of the circumference (L) of the current-collecting member (5) is selected so that during the impulse test required for the bushing, the root-mean-square average of the surface density of the current flowing across the surface of the layer (3a) close to the contour line (L) is smaller than the root-mean-square average of the withstand current density for the layer (3a) exposed to a pulse of a shape and duration similar to the shape and duration of the current flowing through the connection (6) during the impulse test of the bushing.
  3. A bushing according to claim 1 or 2, characterised in that the layer (3a) has surface resistivity greater than 100mΩ per square.
  4. A bushing according to any of the previous claims, characterised in that the current-collecting member (5) has an elongated shape, and it is located on the surface of the layer (3a) longitudinally with respect to the direction of the longitudinal axis of the bushing.
  5. A bushing according to claim 4, characterized in that the current collecting member (5) is positioned close to the symmetry axis of the field-grading layer (3a).
  6. A bushing according to claims 1, 2 or 3, characterised in that the current-collecting member (5) has an elongated shape, and it is located on the surface of the layer (3a) perpendicularly with respect to the direction of the longitudinal axis of the bushing.
  7. A bushing according to claims 1, 2 or 3, characterised in that the current-collecting member (5) has a shape similar to a geometric figure, composed of many elongated conductive elements (9), positioned parallel to one another and connected crosswise by means of another elongated conducting element (10).
  8. A bushing according to any of the previous claims characterized in that the current collecting member (5) is made of metal foil.
  9. A bushing according to any of the claims 1 to 7, characterized in that the current collecting member (5) is made of a braid or a woven or unwoven fabric containing metal wires, fibers or metal foil strips.
  10. A bushing according to any of the previous claims, characterized in that the current collecting member (5) is electrically connected with the field grading layer (3a) using electrically conducting adhesive or electrically conductive paint.
  11. A high-voltage instrument transformer, characterized in that it comprises a bushing according to the invention.
EP08460041A 2008-10-27 2008-10-27 High-voltage bushing Active EP2180485B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP08460041A EP2180485B1 (en) 2008-10-27 2008-10-27 High-voltage bushing
AT08460041T ATE509353T1 (en) 2008-10-27 2008-10-27 HIGH VOLTAGE FEEDBACK

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP08460041A EP2180485B1 (en) 2008-10-27 2008-10-27 High-voltage bushing

Publications (2)

Publication Number Publication Date
EP2180485A1 EP2180485A1 (en) 2010-04-28
EP2180485B1 true EP2180485B1 (en) 2011-05-11

Family

ID=40336549

Family Applications (1)

Application Number Title Priority Date Filing Date
EP08460041A Active EP2180485B1 (en) 2008-10-27 2008-10-27 High-voltage bushing

Country Status (2)

Country Link
EP (1) EP2180485B1 (en)
AT (1) ATE509353T1 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103534766A (en) * 2011-06-28 2014-01-22 Abb研究有限公司 Improved bushings foil design
CN106463217A (en) * 2014-04-14 2017-02-22 Abb瑞士股份有限公司 A method for manufacturing a perforated, sheet-like high-voltage insulating spacer for a high-voltage component and a high-voltage component comprising a spacer manufactured according to the method
RU2640315C1 (en) * 2016-09-20 2017-12-27 Владимир Ильич Крючков Adjustable capacitive sensor of high voltage
CN113016041A (en) * 2018-11-29 2021-06-22 Abb电网瑞士股份公司 Bushing for an electrical power system

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012163561A1 (en) * 2011-05-27 2012-12-06 Abb Technology Ag Electric component for a high-voltage system
DE102012104137A1 (en) * 2012-05-11 2013-11-14 Maschinenfabrik Reinhausen Gmbh Field controlled composite insulator e.g. rod, has core, shielding sheath and field control layer that is applied by plasma coating to core, where dielectric properties are controlled by geometric structure of field-control layer
EP2911255A1 (en) * 2014-02-19 2015-08-26 ABB Technology Ltd High voltage lead-through device and method of manufacturing the same
CN113131432B (en) * 2020-01-14 2023-03-14 香港浩岳国际有限公司 Explosion-proof plug-in capacitive cable outdoor terminal and preparation method

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB539587A (en) 1940-03-15 1941-09-17 Reyrolle A & Co Ltd Improvements in or relating to electric insulators including stress-grading condenser layers
GB1125964A (en) 1964-09-02 1968-09-05 Bushing Company Ltd Improvements relating to high-voltage resin-bonded laminated electrical insulation
US3875327A (en) 1974-06-06 1975-04-01 Westinghouse Electric Corp Electrical bushing having a spiral tap assembly
DE3001810A1 (en) 1980-01-18 1981-07-23 Siemens AG, 1000 Berlin und 8000 München FILM-INSULATED HIGH VOLTAGE TRANSMISSION WITH POTENTIAL CONTROL INSERTS
DE3001779C2 (en) 1980-01-18 1987-01-02 Siemens AG, 1000 Berlin und 8000 München High-voltage bushing with layers of embossed insulating foils
JPS6010253Y2 (en) 1980-03-07 1985-04-09 日本碍子株式会社 capacitor bushing
US4500745A (en) 1983-03-03 1985-02-19 Interpace Corporation Hybrid electrical insulator bushing
JPH01283716A (en) 1988-05-10 1989-11-15 Mitsubishi Electric Corp Mould bushing
PL206279B1 (en) 2004-06-29 2010-07-30 Abb Spółka Z Ograniczoną Odpowiedzialnościąabb Spółka Z Ograniczoną Odpowiedzialnością Capacitive insulating body of a high voltage culvert

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103534766A (en) * 2011-06-28 2014-01-22 Abb研究有限公司 Improved bushings foil design
CN103534766B (en) * 2011-06-28 2016-01-27 Abb研究有限公司 The sleeve pipe paper tinsel design improved
CN106463217A (en) * 2014-04-14 2017-02-22 Abb瑞士股份有限公司 A method for manufacturing a perforated, sheet-like high-voltage insulating spacer for a high-voltage component and a high-voltage component comprising a spacer manufactured according to the method
RU2640315C1 (en) * 2016-09-20 2017-12-27 Владимир Ильич Крючков Adjustable capacitive sensor of high voltage
CN113016041A (en) * 2018-11-29 2021-06-22 Abb电网瑞士股份公司 Bushing for an electrical power system
CN113016041B (en) * 2018-11-29 2022-03-01 日立能源瑞士股份公司 Bushing for an electrical power system

Also Published As

Publication number Publication date
ATE509353T1 (en) 2011-05-15
EP2180485A1 (en) 2010-04-28

Similar Documents

Publication Publication Date Title
EP2180485B1 (en) High-voltage bushing
Nattrass Partial discharge measurement and interpretation
KR100668977B1 (en) Element for protecting from surge voltage
EP3092500B1 (en) High bandwidth rogowski transducer with screened coil
US5854556A (en) Measurement system for partial discharges on dielectrics in coaxial cables
JPS63126121A (en) Holding system for lightning arrester
CN104865468A (en) Device and method for measuring shielding effectiveness of electromagnetic pulse of thunder and lightning
JP2010261851A (en) Thunder impulse voltage testing apparatus and thunder impulse voltage testing method
Arman et al. The measurement of discharges in dielectrics
Mason Discharge detection and measurements
JP5224825B2 (en) Insulation monitoring device
JPS59153176A (en) Device with measuring and damping resistor
JP3455486B2 (en) Current probe
Aslam et al. Prognostication of Failures Using Signal-to-Noise Ratio to Determine Partial Discharges Activities in Power Transformers
Bellaschi Heavy surge currents—Generation and measurement
Khayam Evaluating the inter-resonance characteristics of various power transformer winding designs
McDermid et al. Partial discharge screening test for internal voids and delaminations in stator coils and bars
JP2002022790A (en) Partial discharge detecting device for gas insulating equipment
AT523550B1 (en) Device and method for localizing partial discharges in medium and high voltage equipment
KR20120037165A (en) High voltage broadband pulse attenuator
RU2237333C2 (en) Apparatus for protecting against super voltage
Khan Transient Voltage Distribution in Bushing
Schon et al. High Impulse Voltages
Borges et al. Investigating core influence on transformers insulation diagnostics
Davis The Parsons Memorial Lecture: High-voltage research at the national physical laboratory

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL BA MK RS

17P Request for examination filed

Effective date: 20100907

AKX Designation fees paid

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602008006903

Country of ref document: DE

Effective date: 20110622

REG Reference to a national code

Ref country code: SE

Ref legal event code: TRGR

REG Reference to a national code

Ref country code: NL

Ref legal event code: VDEP

Effective date: 20110511

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110811

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110912

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110822

Ref country code: BE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110812

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110911

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20120214

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111031

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20111123

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602008006903

Country of ref document: DE

Effective date: 20120214

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111027

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20111027

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110811

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20110511

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20151023

Year of fee payment: 8

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20170630

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20161102

REG Reference to a national code

Ref country code: CH

Ref legal event code: PUE

Owner name: ABB POWER GRIDS SWITZERLAND AG, CH

Free format text: FORMER OWNER: ABB RESEARCH LTD., CH

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20200528 AND 20200603

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: HITACHI ENERGY SWITZERLAND AG, CH

Free format text: FORMER OWNER: ABB RESEARCH LTD., ZUERICH, CH

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: HITACHI ENERGY LTD, CH

Free format text: FORMER OWNER: ABB RESEARCH LTD., ZUERICH, CH

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: ABB SCHWEIZ AG, CH

Free format text: FORMER OWNER: ABB RESEARCH LTD., ZUERICH, CH

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: ABB POWER GRIDS SWITZERLAND AG, CH

Free format text: FORMER OWNER: ABB RESEARCH LTD., ZUERICH, CH

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: HITACHI ENERGY SWITZERLAND AG, CH

Free format text: FORMER OWNER: ABB SCHWEIZ AG, BADEN, CH

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: HITACHI ENERGY LTD, CH

Free format text: FORMER OWNER: ABB SCHWEIZ AG, BADEN, CH

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: ABB POWER GRIDS SWITZERLAND AG, CH

Free format text: FORMER OWNER: ABB SCHWEIZ AG, BADEN, CH

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20211104 AND 20211110

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: HITACHI ENERGY SWITZERLAND AG, CH

Free format text: FORMER OWNER: ABB POWER GRIDS SWITZERLAND AG, BADEN, CH

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: HITACHI ENERGY LTD, CH

Free format text: FORMER OWNER: ABB POWER GRIDS SWITZERLAND AG, BADEN, CH

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230527

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20231020

Year of fee payment: 16

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 20231019

Year of fee payment: 16

Ref country code: IT

Payment date: 20231026

Year of fee payment: 16

Ref country code: DE

Payment date: 20231020

Year of fee payment: 16

Ref country code: CH

Payment date: 20231102

Year of fee payment: 16

REG Reference to a national code

Ref country code: DE

Ref legal event code: R082

Ref document number: 602008006903

Country of ref document: DE

Representative=s name: DENNEMEYER & ASSOCIATES S.A., DE

Ref country code: DE

Ref legal event code: R081

Ref document number: 602008006903

Country of ref document: DE

Owner name: HITACHI ENERGY LTD, CH

Free format text: FORMER OWNER: HITACHI ENERGY SWITZERLAND AG, BADEN, CH

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20240718 AND 20240724