Westinghouse Electric Corporation

Electric Power Research Institute Incorporated

Abb Power Td & Company

Joseph R Rostron

Charles F Cromer

William H Fischer

John R Perulfi

Charles A Peterson

Clive W Kimblin

David Robert Smith

Albert H Maxwell, Jr

William H South

Randall N Avery

Michael W Thomas

Thomas D Poyser

Sylvester J Dropik

John D Borst

John W Bankoske

Paul J Yuran

Kent D Daschke

David W McElroy

A circuit breaker utilizes a plurality of vacuum interrupters immersed in oil. A cross-bar with electrically conductive sections completes a series electrical circuit through the circuit breaker and actuates operating mechanisms, to close the contacts of the vacuum interrupters when in the raised position as the cross-bar is lowered, the contacts of the vacuum interrupters are opened by impact forces before isolation gaps which fill with oil are created in the series electrical circuit. Various arrangements of the vacuum interrupters are disclosed for uprating existing oil circuit breakers.

Multiple vacuum interrupter fluid insulated circuit breaker with

A microprocessor-based transformer monitoring system to provide continuous on-line monitoring and analysis of transformer operation. The transformer monitoring system periodically monitors various parameters related to transformer load and condition. Maximum, minimum, and instantaneous values of the parameters are stored and analzyed. To perform the analysis, a hierarchy of thresholds is associated with each parameter. When a parameter exceeds any one of the thresholds, a response is produced by the transformer monitoring system. The type of response depends on the level of the exceeded threshold in the hierarchy. The range of response produced by the transformer monitoring system includes: continuing normal periodic data collection and analysis, increasing the rate of data collection and analysis, recommending an on-site physical check of the monitored transformer, reducing transformer load, and taking the transformer off line.

Method and apparatus for monitoring transformers

A current transformer characterized by a terminal bushing extending from a tank with a pair of spaced conductors extending through the bushing and into the tank and with the portions of the conductors in the tank being enclosed within tubular means. The assembly of the conductors, bushing, and tubular means being clamped together by resilient (spring) means for holding the conductors in tension and the bushing and tubular means in compression. The transformer also embodies two separate oil systems.

Current transformer

A circuit interrupter uses a dielectric liquid such as sulphur hexachloride to extinguish arcs in an interrupter. The liquid is injected at a relatively high pressure by a pump piston with a relatively high mass and an accumulator acts as a pressure fly wheel to effectively reduce high pressure maximums and increase low pressure minimums because of the much lower mass of the accumulator piston. In addition, a double fluid flow interrupter is provided.

Circuit interrupter using dielectric liquid with energy storage

A minimum liquid circuit interrupter provides a relatively remote cooled storage unit for the dielectric liquid and fills a cylinder which is in close proximity to the insulating nozzle of the interrupter, the cylinder being driven at one end by a piston and closed at the other by the moving contact of the interrupter.

Circuit interrupter using a minimum of dielectric liquid

The invention provides a current interrupter employing a liquified dielectric medium such as sulfur hexafluoride to effect rapid arc extinction. A pump cylinder forces the dielectric liquid into the vicinity of a fixed contact. The pump cylinder is refilled from within the contact enclosure after each current interruption to allow for repeated operations. Check valves are provided for preventing any dielectric gas from entering the pump cylinder. The interrupter system further includes a pressure absorbing accumulator for smoothing pressure changes and a cooler for removing heat from the dielectric medium.

Liquid interrupter module

The invention provides for a gas puffer type current interrupter having a pair of separable contacts, one of which is surrounded by a nozzle formed of electrically insulating material. Upon separation, an arc is drawn between the contacts through the throat of the nozzle. The method of the invention includes permitting the arc to fill and clog the nozzle throat thereby restricting the escape of dielectric gas which is being forced into the nozzle. The clogging of the nozzle by the arc is permitted to an extent sufficient to raise the temperature within the nozzle such that significant ablation of the nozzle material occurs interior of the nozzle. The ablation or evaporation of the nozzle material produces a significant increase in pressure within the nozzle which serves to rapidly extinguish the arc. The interrupter includes a nozzle having a throat size selected so that the cross sectional area of the arc substantially fills the throat. The nozzle will be clogged a sufficient portion of the time between contact separation and arc extinction to produce the desired ablation of the nozzle material.

Gas puffer type current interrupter and method

An improved puffer-type gas-blast circuit-interrupter is provided having a movable operating cylinder assembly movable over a relatively-fixed piston structure. A high compression ratio is obtained during the opening operation by minimizing the 'dead' volume of arc-quenching gas within the movable operating cylinder, and an efficient gas-flow path through the movable cylinder assembly smoothly converges through the movable nozzle throat-area into the drawn arc. A high electrical withstand capability is accomplished by using a generous radius on the lower ends of external stationary main contact fingers, and by shrouding, or shielding the stationary contact probe within the surrounding shield of the stationary contact fingers. The circuit-interrupter of the present invention is adapted for various current ratings, such as 2,000 amperes, 3,000 amperes, or 4,000 amperes, for example, by varying the number of stationary main contact fingers used surrounding the movable operating gas-cylinder. High-interrupting performance is obtained with a reduced residual gas volume at the end of the opening stroke, and, consequently, a higher gas-compression ratio is obtained. The gas-flow downstream of the nozzle throat area is confined within the cluster of stationary main contact fingers, and this cools the ejected gas to prevent voltage breakdown to electrical members at another potential. Open venting ports are provided at the upper end of the stationary contact finger cluster to prevent stagnation of the hot arced gas flowing into the stationary contact finger cluster, which thereby permits the hot arcing gases to be blown out of the way to insure good interrupting performance and a high breakdown value.

Puffer-type compressed-gas circuit interrupter

A multi-pole high-power circuit-interrupter is provided having a single common operating mechanism therefor, and having independent pole tripping operation by associating with at least one of a plurality of the pole-units its independent ball latching means, which may be very quickly mechanically released upon a tripping operation associated with the respective one pole-unit to which said ball latching device is connected. Another important feature of the invention is the provision of a plurality of load-release latching balls, which may be quickly released from their latched position by a pneumatic releasing device, which is energized in response to electrical overload conditions existing in the respective pole-unit to provide thereby a tripping operation for the particular pole-unit, to which the ball-latching releaseable device is mechanically connected. Still another feature of the present invention is the provision of a spring-return catch-member in a ball-latch releasing device, which holds the load-release balls in their latched position, and provides a desirable quick relatching operation at the end of the closing operation of the circuit-interrupter.

Multi-pole high-voltage circuit-interrupter having independent pole

An improved closing resistor support is provided for the closing resistances of high-voltage high-power compressed-gas circuit-interrupters in which the formerly-used insulating straps are completely eliminated, and consequently the voltage conditions are thereby improved to thus withstand a much higher-voltage breakdown capability during the closing operation. A metallic ring is preferably utilized at the front end of the circular closing resistance assemblage and provides a uniform compression of the individual resistor coils and, additionally, provides a desirable electrical field condition at the resistor assemblage.

Closing-resistor support for EHV power circuit-breakers

A high-voltage gas-type circuit-interrupter is provided utilizing a pair of serially-related puffer-type circuit-interrupters mechanically connected together, and operated by a single common operating rod. The stationary contact structures may be supported by rods attached to the interrupter support plate, or, alternatively, by a pair of terminal-bushings extending downwardly interiorly within a surrounding metallic tank at ground potential, for example. The operating arrangement may be such as to involve a linearly movable generally vertically extending common operating rod actuated externally of the grounded gas-filled tank by a suitable operating mechanism. Preferably, the individual puffer-type gas interrupters each involves the linear-slidable operation of a movable operating gas-compression cylinder, carrying the movable contact structure and an insulating nozzle orifice movable over a relatively stationary fixed piston structure.

Double-puffer-type compressed-gas circuit-interrupter constructions

A puffer-type gas-blast circuit-interrupter is provided having an operating cylinder movable over a fixed composite piston structure, the fixed composite piston structure providing a variable cross-sectional area by means of a secondary piston area, preferably annular in configuration, which is releasably latched in a fixed forward position, and, subsequently, during the opening operation of the breaker, collapsed to a retracted position. The composite piston arrangement may be such that upon collapse of the secondary 'fixed' piston, the diameter of the surrounding movable operating cylinder may be such as to closely surround the central area of the primary fixed piston structure to retain high-pressure gas within the piston-compression chamber without loss. There results, by the utilization of the variable-area fixed composite piston structure, an improved interrupting performance of the circuit-interrupter by giving very high gas pressures early in the opening stroke of the circuit-interrupter, as compared to prior-art conventional structures, which provide such high gas pressure only at a later time in the opening stroke by conventional piston means.

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Murrysville, PA, United States of America

Joseph R Rostron