Bbc Brown, Boveri & Company, Limited

Georg Koppl

Gerhard Linhofer

Leopold Blahous

Adelbert Rappange

Helmut Nowack

Adolf Eidinger

Osvin Gaupp

Carl D Flossel

Hans Schibli

Alfred Ulrich

Violi Carmelo

Thomas Gysel

Giovanni Pedrini

Hans Widmer

A safety mechanism is described which is used in an electrical distributing system with a bus-bar and of branches emanating from the bus-bar and has safety relays which turn off the malfunctioning part of the system in case of error. In this safety mechanism, redundancy is increased with respect to a malfunctioning of any one of the relays while the number of safety relays remains the same. This is achieved by the fact that each of the safety relays responds to a measurement of currents and voltages of two branches and acts upon both branches via the switches separating them from the mains.

Safety mechanism for electrical power line

In a high-voltage switching system, nodes (1, 2, . . . , 8) are connected in the form of a ring via switching points (12, 23, . . . , ) which in each case contain a circuit breaker. In this system, the breaking currents of the circuit breakers are to be limited and thus the breaking capacity of the circuit breakers provided in the system is to be reduced if a short-circuited part (for example node 1) is separated from a faultless part of the system. This is achieved by opening a switching point (for example 45) of the nodes connected in the form of a ring, between the contact feeders of which switching point and the non-available node (for example (1) in each case at least one available node (for example 2, 3, 4, 5, 6, 7, 8) is provided, via which a component short circuit is fed into the ring. It is of particular advantage in this case to open that switching point (for example 45) which divides the short circuit current flowing towards the short-circuited part (for example node 1 ) into two approximately equal halves, since then the maximum breaking current in the power-switching points (for example 12, 18) only needs to be half the maximum short circuit current of the high-voltage system.

Method for limiting the fault-generated currents of circuit breakers in

A coolable electrical component having a housing (1) filled with insulating gas, and a conductor (2) of hollow cylindrical construction causing a high voltage, arranged in this housing (1). Through the interior space (7) of the conductor a coolant is circulated. The electrical component occupies a smaller space and yet allows increased current load capacity. This is achieved by providing a high-pressure tank (19) extending in the longitudinal direction of the conductor (2) in the interior space (7) thereof. The tank is connected to a gas liquefaction installation by means of outlet orifices (18) perforated in its wall at regular intervals thereof. Such a componet may preferably be a tubular gas cable or a component of a gas-insulated, metal-encapsulated switchgear.

Coolable electrical component

To provide a high-voltage switch which can switch off in a very short time, namely in a half-period, rapid severing of the isolating screws (36) is utilized, and the high-voltage switch is designed so that the switch-off and switch-on device contains at least one isolating screw (36) by means of which a prestressed rod (28) connected to the movable contact of the high-voltage switch can be released. The half-period high-voltage switch according to the invention is used appropriately in switching systems where the half-period high-voltage switch is connected in series with at least one power circuit-breaker. The advantage is to be seen especially in the use of the high-voltage switch in switching systems where it permits a limited short-circuit cut-out capacity.

High-voltage switch and its use

A switchgear installation has at least four junctions connected in the form of an annulus. These junctions are connected with each other by means of interruptable current branches. Each junction of a first group of junctions containing at least two elements may be connected with each junction of a second group of junctions by means of a bridging branch. The bridging branches contain a common power or load switch together with a plurality of disconnecting switches, which are provided between a first supply terminal of the power or load switch and each junction of the first group and between a second supply terminal of the power or load switch and each junction of the second group.

Switching network

A switching network has at least four nodes which can be connected in each case via three interruptable current branches to other ones of the nodes. These nodes can be connected in at least two partial rings. In order to retain the redundancy of such a system in the case of an expansion to more than four nodes with negligible equipment expenditure and, at the same time, little space requirement, the partial rings are constructed in such a manner that they do not have a common node in a preferred embodiment. In this arrangement, each node of a first one of the two partial rings can be connected to a node of a second one of the two partial rings and, conversely, each node of this partial ring can be connected to a node of the first partial ring. The switching network can be advantageously used, in particular, in high-voltage supply systems.

Switching network particularly for high voltage supply systems

A compressed-gas switch has a stationary and a movable switching part. At the movable switching part a nozzle of insulating material and an annular element consisting of insulating material are provided. The nozzle of insulating material and the annular element delimit an outer inlet duct and an annular element and a burn-off contact of the movable switching part delimit an inner inlet duct. The inlet ducts are connected to a compression space, filled with quenching gas, of a piston-cylinder device which can be actuated by the movable switching part. During a switching-off process the quenching gas, which is under high pressure in the compression space, is conducted by the inner and outer ducts, into the switching path. This switch is now to be developed further in such a way that both short-circuit currents at a distance and those at the terminals can be switched off with high reliability. This is achieved by making the minimum flow cross-section of the outer inlet duct smaller than the minimum flow cross-section of the inner inlet duct and by attaching at the narrowest point of the annular element a conductive ring with the clear width of the conductive ring smaller than the clear width of the annular element.

Compressed-gas switch

A circuit breaker is disclosed in which a compressed quenching medium, heated by an arc, is rapidly removed from a main duct in such a manner that the arc is effectively blown by axially opposing flows of quenching medium. The circuit breaker includes a nozzle made of an insulating substance and having the main duct. A first contact piece is slidingly accommodated in the main duct, and a second contact piece is fixedly connected to the nozzle. The nozzle includes a first blow duct having a first blow orifice, and an exhaust duct having an exhaust orifice. A second blow duct having a second blow orifice is included between the nozzle and the second contact piece. The first and second blow orifices are axially spaced from each other, and the exhaust orifice is located between the first and second blow orifices.

Circuit breaker

A device for quickly reconnecting two portions of a current carrying line after separation of the line portions through actuation of a circuit breaker includes a second circuit breaker and a serially connected switch connected in parallel with a primary circuit breaker. Closure of the switch reconnects the line portions through the second circuit breaker after actuation of the primary circuit breaker. The switch can include auxiliary contacts for supplying power to an ignition device associated with the second circuit breaker, to render the second circuit breaker operable only when the switch is closed.

Current limiting device for high voltage switching mechanisms

An electrical gas blast circuit breaker is disclosed including first and second compartments for a pressurized quenching gas. The first and second compartments are connectible with the connection actuating valve members of each compartment. The actuation of the valve members automatically provides communication between the compartments upon connection of the compartments together. Transportation covers may be provided to releasably seal the ends of the compartments after manufacture and before connection of the compartments. The valve members are preferably spring biased with each valve member urged against the spring bias during connection of the compartments.

Electrical gas-blast circuit breaker and method of manufacture

An electrical switch in which during a switchoff operation the switchoff current is commuted from a continuous current path through the switch to an extinction current path which includes a pair of separable contact members one of which is located in a region of the switch housing within which a relatively low gas pressure exists, the other contact member being located within a pressure chamber in which a higher gas pressure is generated during the switchoff operation by heating the gas electrically with an auxiliary rotating arc drawn between a pair of arcing members located within the pressure chamber and which disengage during the switchoff movement. The heated and pressurized gas within the pressure chamber is discharged through a small opening in a nozzle which is opened as the contact members separate thus blasting and extinguishing the arc formed therebetween.

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Birr, Switzerland

Georg Koppl