Abstract: A cured filler-less epoxy compound formed as a rigid, three-dimensional, transparent structure, including a cylindrical sight bowl of a utility or industrial high voltage bushing. A process for making a three-dimensional (e.g., cylindrical), transparent structure with improved strength, including the steps of obtaining a cured filler-less epoxy compound and then pre-stressing the filler-less epoxy compound.

Abstract: A switching device has an improved fastening arrangement to join an electrical insulating body with a conductive metal mounting piece or flange. The fastening arrangement involves a plurality of standard hardware fasteners. The quantity of fasteners required to join the insulating body and flange is dependent upon the desired strength of the joint and the size (or diameter if the insulating body is tubular shaped) of the insulating body.

Abstract: A novel solenoid assembly is shown to include a solenoid having an armature and a delay member. The delay member delays movement of the armature from a first position to a second position until some desired condition occurs, for example, until a desired period of time has passed, until the solenoid is capable of generating a desired amount of force or until the current applied to the solenoid reaches a desired level. In a preferred embodiment, the delay member is a spring positioned to bias the armature against movement until the desired condition has occurred. In such an embodiment, the spring may be positioned to exert force against a shoulder formed on the armature. It is also preferred for the solenoid assembly to include a spacer, positioned between the solenoid and the mechanism being controlled by the solenoid. The spacer serves to space the armature from the mechanism when the armature is in the first position.

Abstract: An amorphous magnetic core is produced by wrapping cut strips of amorphous metal about a mandrel to form a distributed gap core. The cut strips are secured to the mandrel during assembly by wrapping the strips with amorphous metal ribbons that have been weakened in predetermined areas but not fully parted. After the core has been built to its desired size, the weakened ribbons are completely parted. This method of making an amorphous magnetic core produces a tightly wound distributed gap core without the need for a belt winder or specialized strip holding devices.

Abstract: A relay test set of reduced size and weight includes a small, highly efficient voltage and current source. The test set incorporates a Class D switching amplifier design that greatly reduces the size of the power source needed to inject the correct voltage and current into the secondary inputs of a protective relay. To further reduce the size, weight and cost of the relay test set, a single voltage amplifier is used to drive both voltage and current secondary inputs of a protective relay. In so doing, this test set then becomes both a voltage transformer and current transformer simulator utilizing a single voltage power source at reduced size, weight and cost. To make the power source variable while maintaining accuracy, a microcomputer module is used to monitor both current and voltage being injected into the protective relay.

Abstract: Arc-quenching fuse tubes comprising an elongated tubular body having an inner arc-quenching surface layer which comprises an arc-quenching matrix comprising a fibrous material and an arc-quenching composition. The arc-quenching compositions comprise a cured composition of an aromatic epoxy resin and a linear aliphatic epoxy resin.

Abstract: High oleic acid triglyceride compositions that comprise fatty acid components of at least 75% oleic acid, less than 10% diunsaturated fatty acid component; less than 3% triunsaturated fatty acid component; and less than 8% saturated fatty acid component; and having the properties of a dielectric strength of at least 35 KV/100 mil gap, a dissipation factor of less than 0.05% at 25 NC., acidity of less than 0.03 mg KOH/g, electrical conductivity of less than 1 pS/m at 25 NC., a flash point of at least 250 NC. and a pour point of at least −15 NC. are disclosed. Electrical insulation fluids comprising the triglyceride composition are disclosed. Electrical insulation fluids that comprise the triglyceride composition and a combination of additives are disclosed. Electrical apparatuses comprising the electrical insulation fluids and the use of electrical insulation fluids to provide insulation in electrical apparatuses are disclosed.

Abstract: A de-energized tap changer is disclosed that includes a contact rail assembly, a gear assembly, a handle assembly and a transmission system that compensates for angular misalignment of the gear assembly and handle assembly. The transmission system includes two elongated members with attached blocks that fit inside a hollow tube and when the handle of the de-energized tap changer is rotated, torque is transmitted through the transmission system to the gear assembly which drives the movable contacts.

Abstract: A reach-measurement method is used in connection with a series-compensated line of a power system. The series-compensated line includes an installed series capacitance having a bus side and a line side, and a non-linear protection device parallel to the installed series capacitance. The series-compensated line has a line current, a bus side voltage, and a line side voltage. The series capacitance and the non-linear protection device have a capacitance voltage thereacross equal to the bus side voltage minus the line side voltage. In the method, a number (n) of line current samples are measured, where such samples are representative of values of a line current waveform at successive instants of time on the series-compensated line. Capacitance voltage values are computed based on the measured line current samples in accordance with an equation which takes into account the non-linear protection device parallel to the installed series capacitance.

Abstract: A cryostat for a superconducting transformer is provided that includes non-conducting load bearing insulation and is adapted for use with a superconducting transformer. In addition, the cryostat prevents the formation of closed loop stray currents on its outer case. The cryostat contains the winding sets and other related electrical equipment of a transformer. The cryostat generally comprises a cryogenic tank having an outer wall, a non-conducting liner, and a load bearing insulation layer disposed therebetween. The tank holds a liquid or gaseous cryogenic coolant into which the components of the transformer are immersed. A plurality of passages allow the passage of the limbs of the iron core of the transformer through the tank.

Abstract: A method and system diagnose and measure partial discharge on-line in a power transmission system. A first wideband directional clamp-on detector detects pulses corresponding to partial discharge transmitted via a transmission line. A second wideband directional detector detects pulses corresponding to partial discharge output from at least one bushing tap of a high voltage device. The first and second pulses are nulled and then added and/or subtracted, and a diagnostic and measurement system analyzes the results to determine whether the high voltage device and/or an external source produces partial discharge, determine the type of discharge, and measure the level of discharge. For analysis of internal partial discharge, external partial discharges are rejected. The diagnostic and measurement system simultaneously analyzes multiple phases of the output of the high voltage device, while the device is energized. A method and system also diagnose and measure partial discharge off-line in a high voltage device.

Abstract: High oleic acid triglyceride compositions that comprise fatty acid components of at least 75% oleic acid, less than 10% diunsaturated fatty acid component; less than 3% triunsaturated fatty acid component; and less than 8% saturated fatty acid component; and having the properties of a dielectric strength of at least 35 KV/100 mil gap, a dissipation factor of less than 0.05% at 25° C., acidity of less than 0.03 mg KOH/g, electrical conductivity of less than 1 pS/m at 25° C., a flash point of at least 250° C. and a pour point of at least —15° C. are disclosed. Electrical insulation fluids comprising the triglyceride composition are disclosed. Electrical insulation fluids that comprise the triglyceride composition and a combination of additives are disclosed. Electrical apparatuses comprising the electrical insulation fluids and the use of electrical insulation fluids to provide insulation in electrical apparatuses are disclosed.

Abstract: A method for measuring a fundamental frequency of a power system comprises sampling voltage and current waveforms associated with the power system, wherein the voltage and current waveforms are characterized by a fundamental frequency component that may vary over time. Next, determine whether, according to a prescribed frequency tracking criterion, a present value of the fundamental frequency can be measured using voltage samples. If so, measure the fundamental frequency using the voltage samples, and set a best available value (“freq”) equal to the measured value based on voltage samples. If the fundamental frequency cannot be measured using the voltage samples, determine whether, according to the prescribed frequency tracking criterion, the present value of the fundamental frequency can be measured using current samples. If so, measure the fundamental frequency using the current samples and set the best available value equal to the measured value based on current samples.

Abstract: High oleic acid triglyceride compositions that comprise fatty acid components of at least 75% oleic acid, less than 10% diunsaturated fatty acid component; less than 3% triunsaturated fatty acid component; and less than 8% saturated fatty acid component; and having the properties of a dielectric strength of at least 35 KV/100 mil gap, a dissipation factor of less than 0.05% at 25° C., acidity of less than 0.03 mg KOH/g, electrical conductivity of less than 1 pS/m at 25° C., a flash point of at least 250° C. and a pour point of at least −15° C. are disclosed. Electrical insulation fluids comprising the triglyceride composition are disclosed. Electrical insulation fluids that comprise the triglyceride composition and a combination of additives are disclosed. Electrical apparatuses comprising the electrical insulation fluids and the use of electrical insulation fluids to provide insulation in electrical apparatuses are disclosed.

Abstract: An oil filled power bushing for a transformer in which the oil and nitrogen are separated by a movable piston within an expansion chamber for dividing said expansion chamber into a liquid filled section and a gas filled section, and means for sealing said piston with respect to a conductor and said expansion chamber.

Abstract: An adjustable throat for protecting electrical connections between two mating pieces of electrical equipment such as a transformer and associated switchgear is disclosed. The adjustable throat includes two telescoping tubular members each having flanges at one end thereof with oversized holes for connection respectively to a transformer and associated switchgear. The holes allow for vertical and horizontal adjustment to provide for final adjustment in these directions. One of the tubular members also has elongated open ended slots to allow the throat to be adjusted in and out to allow final connection to the switchgear without the need for minor movement of the gear.

Abstract: A system and method for detecting a flicker of electrical energy provided via a service type to an energy meter. The system comprises a memory for storing a respective voltage threshold for each different service type; a digital signal processor for measuring a respective phase voltage for each meter element of the energy meter; and a microcontroller for retrieving the voltage threshold for the service type from the memory and comparing the measured phase voltage to the voltage threshold to determine an occurrence of flicker.

Abstract: A density monitoring assembly for use in monitoring the gas density within a high voltage circuit breaker tank is disclosed. The density monitoring assembly is coupled directly to an exterior surface of said tank and provides electrical signals indicative of the density of gas within the tank. The assembly comprises a cover that encloses the density monitoring device. The device itself is used to retain the cover. A ball valve and a shraeder type valve are provided to allow testing of the device.

Abstract: A Voltage Instability Predictor (VIP) estimates the proximity of a power system to voltage collapse in real time. The VIP can be implemented in a microprocessor-based relay whose settings are changed adaptively to reflect system changes. Only local measurements (voltage and current) at the bus terminal are required. The VIP detects the proximity to collapse by monitoring the relationship between the apparent impedance {overscore (Z)}app and the Thévenin-impedance. In addition, we disclose: (1) that the VIP may be used in connection with non-radial topologies; (2) a new, more robust method to track voltage collapse in terms of impedance using rolling sums; and (3) a new method for representing distance to voltage collapse in terms of power margins.

Abstract: A ground fault location system is used in a multi-phase ungrounded or high-impedance grounded power network. A signal generator is coupled to the network at a first location and generates for each network phase an individual non-DC voltage signal between such phase and ground. A ground fault detector is coupled to the network at a second location and has a summing device and an annunciator. The summing device is coupled to all of the phases of the network at such second location, sums any current passing therethrough, and produces a sum signal. The annunciator receives the sum signal and provides an indication when such signal is non-zero. Each phase of the network at the second location has a distribution current passing therethrough, the sum thereof normally being substantially zero and resulting in a substantially zero sum signal and the lack of an indication from the annunciator based on such distribution currents.