Abstract: Twin metal billets are fed to dual circumferential grooves formed in a rotating wheel. The billets are advanced first to a wedge-shaped gap which deforms the billets and are then advanced to a die. The die has a die opening with a circumferentially discontinuous, annular cross-section. The metal from each billet merges in the die opening and exits therefrom in the form of a slit tube. The tube is then opened and flattened to form a flat strip by advancing the slit tube over a forming member having a progressively increasing width. As the tube is advanced over the forming member, an alignment system maintaining the tube in a centered position. The alignment system includes a light source disposed within the tube and two arrays of photo-transistors arranged to receive light from the light source, the amount of light sensed by each array being a function of the position of the slit in the tube relative to a desired position.

Abstract: A guidance system for an interrupter switcher comprising a first guide positioned in between the contact support and the movable contact system of the interrupter, and a second guide inserted into the stationary contact system of the interrupter. According to the invention the second guide is capable of receiving the nozzle of the movable contact system. An interrupter with the guidance system is assembled by positioning the first guide between the contact support and the movable contact system, positioning the second guide within the stationary contact system, inserting the nozzle of the movable contact system into the second guide, and mounting the stationary contact system in the interrupter housing. The assembly of an interrupter with a guidance system results in a self-adjusting switcher interrupter capable of maintaining a stable alignment between the interrupter's movable and stationary contacts while opening and closing the interrupter.

Abstract: A dead tank high voltage SF.sub.6 circuit breaker has a stationary cylinder SF.sub.6 puffer section, an arc generated SF.sub.6 pressure blast section, a moving arcing contact plug, and a moving open position shield. The contacts are operated by a reduced size operating mechanism which can be used for both 145 kV and 242 kV circuit breakers.

Abstract: Switch operator having an actuator, a drive mechanism coupled to the switch for actuating a switch in response to a rotational force applied to the drive mechanism, and a flexible shaft which couples the actuator to the drive mechanism and communicates the rotational motion of the actuator to the drive mechanism. An interlock mechanism prevents the actuation of a second switch as a function of a first switch and prevents the opening of a door as a function of the position of the first switch.

Abstract: The present invention provides a floating shield for a high voltage bushing. Preferably the bushing is conically shaped and has a composite housing for substantially optimizing the electrical performance of the bushing according to the invention. The floating shield is preferably suspended within the bushing housing by a supporting insulator placed in a low electrical stress region of the bushing. In a preferred embodiment, the supporting insulator is disposed between a ground grading shield and the bushing housing. The composite housing preferably provides a protective inner tube made of a fiber reinforced material and an outer silicone rubber housing having weather sheds formed in a helix on the surface of the housing.

Abstract: Methods and apparatus for supplying power for use in metering electrical energy over a wide range of voltages with a single meter are disclosed. The wide ranging meter includes a processing unit for processing divided input voltage and a current component in order to determine electrical energy metering values. The processing unit is operable in response to supply voltages. A power supply, connected to receive the undivided voltage component, generates the supply voltages over the wide dynamic range. It is especially preferred for the power supply to include a transformer having first, second and third windings, wherein the undivided voltage component is provided to the first winding and wherein the second winding defines the output of the power supply. A switching member is connected to the first winding for permitting and preventing the flow of current in response to a control signal. A control member generates the control signal in response to the output of the power supply.

Abstract: A fault location system comprises voltage/current transducers 10A, 10B located at terminals A and B, respectively; digital relays 12A and 12B respectively coupled to transducer blocks 10A and 10B; and a fault location estimation processor 14, which may comprise a substation controller at substation S.sub.A or substation S.sub.B, a relay at A or B, a stand alone computer at A or B, or a computer at a central location. The digital relays receive analog voltage and current signals (V.sub.A, I.sub.A, V.sub.B, I.sub.B) from the respective transducers and output digital phasor or oscillographic data to the fault location estimation block. The fault location estimation block is programmed to provide the fault location parameter m. The fault location estimation provided by the inventive technique is unaffected by the fault resistance, load current, mutual coupling effects from a parallel line, uncertainties in zero sequence values, shunt elements, and X/R characteristic of the system.

Abstract: A method of securing a flexible temperature sensing element to a duct spacer element of the type which is commonly used in an electrical transformer includes steps of forming a groove in a surface of duct spacer element; and securing a flexible temperature sensing element within the groove so that the flexible temperature sensing element does not protrude from the groove beyond the surface in which the groove is formed. In this way, the duct spacer element and sensing element may be assembled into an electrical apparatus such as a transformer without imparting destructive mechanical forces to the sensing element. The disclosure also embraces an integrated temperature sensing duct spacer unit.

Abstract: A vaporizable material, for example, a silicone, that is buried beneath the surface of a Teflon nozzle for a sulfur hexafluoride power circuit breaker in an area of the nozzle which is exposed to abrasion and wear due to arc products. In a similar manner, aluminum or titanium or some other vaporizable material is buried beneath the surface of the contact of the circuit interrupter which is exposed to abrasion and wear. When the buried layers are exposed due to abrasion of their covering surfaces, these materials will be vaporized and their presence will be sensed by sensors within the circuit interrupter, thus revealing some predetermined degree of wear of the surfaces of the nozzle and contact and other surfaces within the circuit interrupter which may also be subject to abrasion by arcing or arc products. When aluminum is used as the vaporizable material for the contact, it also senses the presence of flashover to aluminum exterior housings.

Abstract: A sub-cycle digital distance relay which uses only the first N/2 samples after a fault to calculate the distance to the fault using a Full Cycle Fourier Algorithm which operates on N samples, where N is the number of samples taken in a cycle of the power signal. The DC offset in the first N/2 samples taken after detection of the fault is cancelled using the N/2+1 sample taken after detection of the fault. The resulting DC adjusted N/2 samples are then multiplied by -1 in order to take advantage of the symmetry of the sine wave of the power signal in estimating the remaining N/2 samples of the first cycle of the power signal after detection of the fault. By so calculating N/2 artificial samples from the first N/2 actual samples taken after the fault, the digital distance relay of the invention can estimate the distance to the fault and thus provide a reliable trip signal in less than one cycle of the power signal.

Abstract: An automatic secondary disconnect mechanism for an electrical switchgear apparatus having an enclosure and a removable circuit device is disclosed. According to a preferred embodiment, the automatic secondary disconnect mechanism comprises a guide rail mounted to the enclosure so as to extend substantially parallel to the racking motion of the circuit device; a slide member slidably mounted on the guide rail; apparatus for locking the slide member in place on the guide rail at a point corresponding to a test position of the circuit device; and apparatus for releasing the slide member when the circuit device reaches the test position from the disconnect position. One of a pair of mating secondary contact members is coupled to the slide member, while the other mating contact member is coupled to the circuit device.

Abstract: A system and method for controlling time-critical functions by dynamically adjusting the interrupt frequency of a microprocessor. Interrupts are generated at a predetermined frequency. Time-critical functions are then performed in response to the interrupts. The interval is adjusted based on timing data from a substantially accurate source. Where the interval is measured in terms of clock pulses, a non-integer number of pulses per interval is attained by varying the number of pulses per interval so that the average over a number of intervals is equal to the non-integer number of pulses per interval. The interval is further adjusted using a selected damping coefficient to eliminate an underdamped condition.

Abstract: Disclosed is a method of making a repairable transformer having an amorphous metal core. The three uncut legs of an annealed wound amorphous metal core are covered with an adhesive material while leaving the cut leg and both adjoining radii covered, but not bonded. The core joint is opened and coils are placed over the legs that adjoin the cut leg. The core joint is closed and the edges of the joint and both adjoining radii are covered with an inner layer of porous material which is secured by an outer wrap of electrical grade steel. The resulting transformer can be easily repaired by unwrapping away the porous material that covers the cut leg and the adjoining radii, opening the core joint, replacing a defective coil or core, reclosing the core joint, and rewrapping the porous material and reclosing the outer layer of electrical grade steel.

Abstract: An improved phase angle regulator with about 70% of the total impedance in the series unit and 30% in the excitor unit. In order to balance the physical size of both units, the excitor unit includes an interleaved winding arrangement. On large phase angle regulators, the higher impedance in the series unit allows for the use of a three-leg core design, and the low impedance interleaved excitor unit can also be designed on a three-leg core. The higher impedance series unit reduces the zero sequence current in the unit by about 40% during a single line to ground fault. Also the interleaved winding arrangement in the excitor unit improves its short circuit withstand capability.

Abstract: A general purpose programmable communications interface designed to support a wide variety of serial synchronous and asynchronous communication protocols. A universal protocol communications (UPC) interface is designed to operate on a VME bus in conjunction with a CPU board which contains the application software that utilizes the communications capabilities of the UPC interface. Per channel DMA is available on input/output lines of the interface together with bit level control for message processing so that a variety of bit oriented communications protocols may be supported by simple reconfiguration of the receiver/transmitter of the programmable UPC interface. In a preferred embodiment, a dynamically variable bit length shift register is used to organize the received and transmitted data into serial packets of the appropriate size on a per channel basis independent of the actual width of the shift register.

Abstract: A winding configuration for a transformer equipped with a load tap changer which maintains an impedance balance when the transformer is connected in parallel with another transformer in the field. The winding configuration, from the core outward, consists of a first compensating winding, a low voltage (LV) winding, a load tap changer (LTC) winding, a high voltage (HV) winding, and a second compensating winding. If the impedance of the transformer has to be lowered to match the impedance of the existing unit in the field, the second compensating winding is coupled in series with the LV winding. If the impedance of the transformer has to be increased to match the impedance of the existing unit in the field, the first compensating winding is coupled in series with the LV winding.

Abstract: Twin metal billets are fed to dual circumferential grooves formed in a rotating wheel. The billets are advanced first to a wedge-shaped gap which deforms the billets and are then advanced to a die. The die has a die opening with a circumferentially discontinuous, annular cross-section. The metal from each billet merges in the die opening and exits therefrom in the form of a slit tube. The tube is then opened and flattened to form a flat strip by advancing the slit tube over a forming member having a progressively increasing width.

Abstract: A device for partially shearing single or multiple sheets of material comprising a base having a recess and a lower blade fixed in the recess. A pair of movable blades having opposed ends are pivotally attached to the base at one end. A lost-motion connecting link connects the free ends of the pair of movable blades together and is connected to a hydraulic piston which moves the link a limited distance towards the base, thereby to rotate both movable blades relative to the fixed blade with a scissors-like action. When the pair of blades is moved towards the lower blade, the material is cut inward from both sides or edges of the material, leaving an inner uncut portion of material having a width which corresponds to the stroke of the movable blades.

Abstract: An assembly for mounting a transformer in a tank, comprising a top and bottom frame, the transformer being located between the top and bottom frames. A plurality of slots are disposed in a row in the top frame. L-shaped brackets are provided for securing the transformer to the tank. The brackets include a toggled end disposed on one end and a shear lug located interior of the toggled end. The toggled end and the shear lug are each disposed in one of the plurality of slots to secure the transformer with the tank. The plurality of slots allow relocation of the brackets along the top frame. A bore is also disposed in the L-shaped bracket. A mounting screw extends through the bore and through one of the plurality of slots in the top frame to further secure the top frame to the tank, the mounting screw maintaining electrical continuity between the top frame and the tank. The shear lug bears any lateral forces which would be otherwise received by the ground screw.

Abstract: A fiber optic data interchange network comprising a plurality of nodes, or drops 10a, 10b, 10c . . . , interconnected by fiber optic cable 12 (FIG. 1 ). Encoded data signals originating at any node are circulated around the network, allowing multipoint (or multidrop) data interchange. Each node includes a data encoder, transmitter, fiber optic receiver, data decoder, clock recovery circuit, and a repeater, i.e., a combination of the fiber optic receiver, an invertor (providing pulse width distortion correction) and the fiber optic transmitter. Thus each node is capable of originating data transmissions and receiving/relaying transmissions from a preceding node.