Asea Brown Boveri Ag

Abb Schweiz Ag

Abb Technology Ag

Abb Management Ag

Abb Research Ltd.

Asea Brown Boveri Inc.

Asae Brown Boveri Ag

Walter Schmidt

Felix Greuter

Reto Kessler

Petra Kluge-Weiss

Yvo Dirix

Robert Hauser

Elias Julke

Bernhard Doser

Bertil Moritz

Daniel Müller

Werner Hofbauer

Peter Zeller

Klaus Giese

Peter Oehlschl&auml;ger

Walter Nydegger

Peter Leupp

Christoph Schupbach

The polymer compound contains a polymer matrix and a filler embedded in the matrix. The filler comprises two filler components with nonlinear current-voltage characteristics deviating from one another. By selection of suitable amounts of these filler components, a polymer compound with a predetermined nonlinear current-voltage characteristic deviating from these two characteristics can be formed in this way.

Polymer compound with nonlinear current-voltage characteristic and process for producing a polymer compound

The surge arrester contains a tubular encapsulation () of electrically conductive material that is filled with an insulating gas, an insulator () that is held on the encapsulation () and serves for supporting a current conductor (R) that is connected to a high voltage, an active part (R) that is arranged in the encapsulation () and comprises at least one varistor column () that is aligned along the encapsulation axis (A) and a field control element (). In order to maintain the manufacturing costs of this arrester at a low level, the field control element () and a first plug-type contact () of a plug connection () are held on the current conductor (R) of the insulator (), and a high-voltage electrode () of the varistor column () that is connected in an electrically conductive fashion to the current conductor (R) via the plug connection () contains the second plug-type contact () of the plug connection ().

Gas-insulated surge arrester

The apparatus is intended for disconnection of a live electrical conductor and has an enclosure () and two power connections () which are passed out of the enclosure (). A conductor section () which connects the two power connections () to one another and a propellant means are arranged in the enclosure interior (). The propellant means is used to produce an amount of compressed gas which is sufficient to disconnect the conductor section () when a fault current occurs. The propellant means is kept free of combustible substances and is chosen such that the amount of compressed gas which is required for disconnection can be thermally released from the propellant means by the electrical work produced by the fault current. Since explosive substances are avoided in the apparatus, the apparatus can be produced, transported, installed and maintained completely safely. After being commissioned, the apparatus is distinguished by high operational reliability.

Isolation apparatus

The active part which is provided for use in a surge arrester includes two connecting fittings, which are arranged along an axis at a distance from one another, at least one cylindrical varistor column, which is provided between the two connecting fittings, and at least one dielectric loop. This loop is supported on the two connecting fittings and thus holds the active part together, thus forming a contact force. The active part is distinguished by a small physical height and little use of materials. This is achieved in that at least one of the two connecting fittings has an electrode, which is arranged at right angles to the axis and is in the form of a plate, as well as an electrical connection, which is integrally formed on the plate. Furthermore, supporting means which are in the form of shoulders are provided for the dielectric loop, and are formed in the plate and/or are integrally formed at the edge of the plate.

Active part for a surge arrester

The component with fault arc protection has an insulator in the form of a pillar, a first electrical conductor system which is provided on the insulator head and can be connected to high-voltage potential, and a second electrical conductor system which is provided on the insulator foot and can be connected to a ground potential. Each of the two electrical conductor systems contains an arcing electrode ( ) for dissipating any fault arc which occurs in the event of a discharge between the two electrical conductor systems. The fault arc is dissipated particularly effectively if at least one of the two arcing electrodes ( ) is in the form of a cup and has a cup base ( ), which is attached to one electrical connection of the first or of the second electrical conductor system, as well as a cup wall ( ) which is adjacent to the cup base ( ) and extends predominantly in the direction of the axis ( ) of the pillar. In this case, at least two material recesses are formed, which extend from the cup base ( ) to the cup rim ( ) and are predominantly in the circumferential direction in the cup wall ( ).

Electrical component with fault arc protection

The surge arrester has a cylindrically symmetrical housing which can be grounded and through which a plug connection is passed which can be brought to a high-voltage potential. An active part which is aligned along the axis of symmetry is arranged in the housing and has two connection fittings and at least one varistor element arranged between the two connection fittings. The connection fittings and the at least one varistor element are braced with respect to one another by at least one loop forming a contact force. The insulation between the active part and the housing is ensured by a dielectric sleeve. The housing is in the form of a dielectric sleeve. The housing is in the form of a bottle and has a housing section in the form of a bottle neck, in which an electrical conductor is routed, which is connected to one of the two connection fittings, is electrically conductively connected to the plug connection, and is cylindrically symmetrical.

Surge arrester

The electrical apparatus, which is preferably designed as a surge arrester (3), has an apparatus, which contains a current sensor, for indicating a fault state caused by a fault current (I). The indicating apparatus furthermore contains a receiver (read station 9), which can be operated from ground potential, for electromagnetic waves as well as an information carrier (8) which interacts with the current sensor and emits electromagnetic waves to the receiver (9). In such an apparatus, the fault state can be identified independently of optical signals.

Electrical apparatus, in particular a surge arrester, having an

The electrical apparatus, which is designed in particular as a surge arrestor (3), has a dielectric housing (8) which can be loaded with high voltage as well as an apparatus for optical indication of a fault state caused by a fault current. The indicating apparatus is designed as an information carrier (9) which covers at least a portion of the outer surface of the dielectric housing (8). This information carrier (9) emits an optically detectable signal when heated to a limiting temperature which is above a permissible operating temperature of the apparatus. The information carrier (9) is advantageously designed as a thermocolor. A faulty apparatus can then be identified by the maintenance personnel for a system containing the electrical apparatus, in a simple and reliable manner by means of a color change.

Electrical apparatus, in particular a surge arrestor, having an

The overvoltage suppressor contains two connecting fittings (1, 2), which are spaced apart from one another along an axis (z) and between which at least one cylindrical varistor element (8) is arranged. The connecting fittings (1, 2) and the at least one varistor element (8) are braced with respect to one another, forming a contact force, to form a mechanically robust active part of the overvoltage suppressor. The active part is sheathed by a molded housing made of insulating material. In each case one material cutout is formed in each of the two connecting fittings (1, 2) with a section (15, 16) which runs essentially transversely with respect to the axis (z), is designed in the form of a slot and extends from the outer surface of the fitting (1, 2) to beyond the axis (z). A loop (5), which absorbs the contact force, is inserted into the sections (15, 16), which are in the form of slots, in the region of the loop ends beyond the axis (z), and each of the two loop ends rests on in each case one surface (17, 18) which bounds the section (15, 16) which is in the form of a slot. The overvoltage suppressor is distinguished by good mechanical and electrical characteristics and can be produced in a particularly cost-effective manner.

Overvoltage suppressor

The surge arrester has an axially symmetrical active portion (2) arranged between two connection fittings (1, 2). This active portion (2) contains varistor elements (12) stacked one above the other and also an axially symmetrical connecting element (13) of electrically conductive material arranged in the active portion (2) of the arrester between two successive varistor elements (12). At least four mounting places (16, 16'), which are uniformly distributed around the axis in the circumferential direction, are formed in the connecting element (13). Two first (16) of the mounting places support respectively one of two first loops (15) which act with contact force on the connecting element (13) and on the varistor elements (12) abutting the connecting element (13). Two second (16') of the mounting places support respectively one of two second loops (15) which act with contact force on the connecting element (13) and on the varistor elements (12) located under the connecting element. Such a surge arrester can have large constructional heights and is distinguished in addition by good mechanical and electrical properties.

An electrical insulator coated with electrically insulating material is disclosed. An electrically insulating material is applied on a primer coat, in which the uniformity of the applied primer coat can be checked in a comparatively simple manner. A fluorescent material is dissolved in the primer solution before being applied to the component. Once dry, the primer coat is exposed to ultraviolet light, which causes the fluorescent material to fluoresce. Points on the surface of the component where the primer defectively coats the components are optically detected from the absence of fluorescent material. Primer is then reapplied to these points.

Method for the production of an insulator

The indicating device (3) is used for signalling a faulty condition of an electrical apparatus, in particular of a surge arrester (1). It contains a sensor (resistor 10) which is located in an insulating material housing (6) and is intended for detecting a fault current flowing through the apparatus, as well as a two-piece metal housing (4) surrounding the insulating material housing (6). The sensor (10) and the insulating material housing (6) are part of a switching element (5). This switching element (5) causes the insulating material housing (6) to spring apart, by the formation of compressed gas, when the fault current occurs and displaces the two parts (shells 12, 13) of the metal housing (4), making the indicating element (16) visible and forming a DC connection which carries the fault current.

Device for indicating a faulty condition of an electrical apparatus, in

A surge arrester includes at least two connection fittings and a one-piece frame, the frame holding the connection fittings. The frame is formed of an insulating material. The surge arrester includes at least one block of varistor material clamped between the connection fittings. The surge arrester further includes an insulating material in which the frame, the block of varistor material and at least part of the connection fittings are cast to form a monolithic body. An arrangement is provided for maintaining a contact force between the connection fittings and the block of varistor material.

The surge arrester contains two connection fittings (1, 2) which are spaced apart from one another along an axis and between which at least one cylindrical varistor element (7) is arranged. The connection fittings (1, 2) and the at least one varistor element (7) are clamped with one another, accompanied by the formation of contact force, to form a mechanically stable active part of the surge arrester. The active part is surrounded by a cast housing (12) made from insulating material. The clamping of the active part is achieved by at least two loops (5) respectively acting independently of one another on the connection fittings (1, 2). The loops (5) are arranged at a distance from the at least one varistor element (7). The connection fittings (1, 2) contain bearing areas which correspond respectively to the number of the loops (5) and are distributed uniformly about the axis azimuthally and on which a loop end is respectively supported. Despite its simple design, the surge arrester has good mechanical and electrical characteristics and can be produced in a particularly cost-effective way.

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Bellikon, Switzerland

Walter Schmidt