Abstract: An electrical module assembly used in a surge arrester is manufactured by wrapping an electrical module assembly including at least one metal oxide varistor (MOV) disk to which a reinforcing structure including a pre-impregnated epoxy/glass-fiber composite has been applied with shrink film and compacting the wrapped electrical module assembly by heating the shrink film such that the shrink film shrinks and applies a radially compressive force to the electrical module assembly. The wrapped electrical module assembly then is cured at a temperature at which the shrink film no longer applies a compressive force.

Abstract: An apparatus includes at least one Rogowski coil and a processor. The at least one Rogowski coil is positioned within an electrical power distribution network to detect a first traveling wave current caused by a fault on an electrical power transmission line of the network, generate a first signal indicative of detection of the first traveling wave, detect a second traveling wave current caused by the fault on the transmission line, and generate a second signal indicative of detection of the second traveling wave. The processor is adapted to receive the first signal and the second signal and to determine, based on the first signal and the second signal, where on the transmission line the fault occurred.

Abstract: A vacuum assembly including a vacuum interrupter may be sealed with a compliant material and/or rubber plugs, so that a cavity is created and maintained within the assembly for use with a current exchange housing and/or bellows, during operation of the vacuum interrupter. During vacuum molding of the vacuum assembly to encapsulate the vacuum assembly in an epoxy, a resulting pressure differential caused by the vacuum molding is prevented from disturbing the seal around the vacuum assembly, by way of a needle or tube included in the seal. In this way, air from within the cavity is allowed to escape, while the epoxy is prevented from entering the cavity. Then, once encapsulation is complete, the vacuum assembly can be joined with an operating rod and other components to complete a vacuum switching device.

Abstract: A current interrupter assembly includes an insulating structure, a current interrupter embedded in the structure, a conductor element embedded in the structure, a current interchange embedded in the structure and connected to create a current path between the current interrupter and the conductor element, and a semiconductive layer covering at least a portion of the conductor element so as to reduce voltage discharge between the conductor element and the structure.

Abstract: A current interrupter assembly includes an insulating structure, a current interrupter embedded in the structure, a conductor element embedded in the structure, a current interchange embedded in the structure and connected to create a current path between the current interrupter and the conductor element, and a semiconductive layer covering at least a portion of the conductor element so as to reduce voltage discharge between the conductor element and the structure.

Abstract: In one general aspect, a system to control and monitor an electrical system includes a switchgear housing unit connected to the electrical system that includes a switchgear mechanism for controlling a connection within the electrical system and electronic controls for monitoring and controlling the switchgear mechanism, where the electronic controls are embedded within the switchgear housing unit to form a single, self-contained unit.

Abstract: A connector system includes a member having a surface with an opening in the surface and an open end defined by one or more walls, where the walls include a first end attached to the surface and a second end having a notch. The connector system further includes a contact element defined by a passage in an axial direction and an opening that is perpendicular to the passage, where the contact element is sized to fit within the open end of the member such that the notch in the second end of the walls aligns with the passage in the contact element. The connector system also includes a probe element connectable to the opening in the surface of the member and the opening of the contact element.

Abstract: A current interrupter assembly includes an insulating structure, a current interrupter embedded in the structure, a conductor element embedded in the structure, a current interchange embedded in the structure and connected to create a current path between the current interrupter and the conductor element, and a semiconductive layer covering at least a portion of the conductor element so as to reduce voltage discharge between the conductor element and the structure.

Abstract: A mechanical reinforcement for an electrical apparatus has at least one electrical element with an outer surface and a reinforcing structure attached to the outer surface. The electrical element may be a monolithic MOV disk or a bonded MOV disk stack. The monolithic element may, for example, have a rating greater than 6 kV. The reinforcing structure may be pre-impregnated fiber matrix that may be, for example, pre-impregnated with resin. The mechanical reinforcement provides improved high current durability to the electrical apparatus.

Abstract: An electrical apparatus includes at least one conductor and an insulation paper surrounding at least part of the conductor. The insulation paper includes a wood pulp fiber, a synthetic fiber, and a binder material. The synthetic fiber is present at between approximately 2 and 25 weight percent.

Abstract: An improved vacuum interrupter is disclosed. The vacuum interrupter includes a ring-shaped structure placed between a contact support structure and an electrical contact associated with the contact support structure. A resistivity of the ring-shaped structure is higher than that of the contact support structure, so that current traversing the ring-shaped structure on its way from the contact support structure to the electrical contact is evenly distributed. The ring-shaped structure may be fit into an end portion of the contact support structure, the end portion having an diameter less than an outer diameter of the support structure, but greater than an inner diameter of the support structure. Alternatively, the end portion may be used without the ring-shaped portion, in which case the electrical contact may be shaped to fit into the end portion.

Abstract: Protection systems for electrical systems such as substation power dividers are described. The protection systems may be designed and used to detect and clear faults that may occur within the substation power dividers. For example, a first Rogowski coil may be used to detect current along a primary conductor, and output a corresponding current signal to a multi-function, differential relay having multiple voltage and current inputs. Similarly, additional Rogowski coils may be used at each of a plurality of secondary feeders, where power from the primary feeder may be distributed to the secondary feeders using a connection bus. By comparing the signals from the first Rogowski coil and the additional Rogowski coils, the differential relay may determine whether a fault exists at some point along the conductor(s) and between the first Rogowski coils and the additional Rogowski coils, including whether a fault is associated with the connection bus.

Abstract: A transformer includes a core defining a core window, a first coil surrounding a portion of the core and including a portion located within the core window, a second coil surrounding a portion of the core and including a portion located within the core window, and a polymer barrier insulation member that is located at least partially within the core window and positioned between the first coil and the second coil.

Abstract: A closed loop feedback system controls electrical switchgear that moves at least one contact relative to another contact to switch power on and off in an AC electrical circuit. The control system includes a position feedback device that is operatively coupled to at least one of the two contacts to produce contact position information. A processor receives and analyzes the contact position information to control contact motion to provide AC waveform synchronized switching. The electrical switchgear may be a capacitor switch that includes a bi-stable over-toggle latching device. The latching device maintains the contacts in one of an open stable position in which electrical current does not flow through the contacts or a closed stable position in which electrical current flows through the contacts.

Abstract: A vacuum interrupter includes end covers having a curved or looped portion, which serves to connect a coil segment of the vacuum interrupter to a ceramic envelope of the vacuum interrupter, and thereby help maintain a vacuum seal for the interrupter. The curved portion acts as a spring when the vacuum interrupter is exposed to heat, thereby absorbing any expansion or contraction in the length of the vacuum interrupter due to the heating or cooling. The curved portion also protects an end of the ceramic envelope from any build-up of metallic arcing products and eliminates the need for elaborate fixturing during assembly. Additionally, a guide may be affixed to the end cover, the guide having ears which ride in a slot in a moving rod of the vacuum interrupter, to thereby prevent a twisting of a bellows of the interrupter during a brazing process. Thus, no elaborate fixturing is necessary to prevent this twisting.

Abstract: A method of joining an end face of a first electric component to an end face of a second electric component includes applying a first metal layer to the end face of the first electric component to form a first metallized layer and applying a second metal layer to the end face of the second electric component to form a second metallized layer. A first fusible alloy layer is applied to the first metallized layer by melting a fusible alloy and propelling the melted fusible alloy onto the first metallized layer, and a second fusible alloy layer is applied to the second metallized layer by melting a fusible alloy and propelling the melted fusible alloy to the second metallized layer. The method further includes contacting the first fusible alloy layer to the second fusible alloy layer. Next, the end faces and fusible alloy layers are heated to melt the fusible alloy layers. After heating, the end faces and fusible alloy layers are cooled to form a bond between the end faces.

Abstract: A rotary tap changer is connected to a power source to control voltage supplied from the power source to a load. The rotary tap changer includes a motor having an output device, and a drive sprocket having a drive shaft positioned perpendicularly to a plane of rotation of the drive sprocket. The rotary tap changer also includes a gear engaged by the drive shaft, a first set of movable contacts, and a transmission device. The first set of movable contacts is coupled to the gear and mounted to conductively engage taps of an electrical control device. The transmission device is coupled to the motor output device and to the drive sprocket such that the motor directly drives the first set of movable contacts for selecting an electrical control device tap.

Abstract: A make-before-break selector switch for use in high-voltage applications allows power to a load to be switched from a first power source to a second power source such that the second connection is made before the first is broken. The selector switch includes a blade coupled to a selector switch control such that the blade may be placed in a first position to electrically couple a first power source electrical contact to a load electrical contact and in a second position to electrically couple a second power source electrical contact to the load electrical contact. T-shaped and v-shaped blade implementations are examples of configurations that may be used.

Abstract: Protection systems are described for electrical systems such as electrical arc furnaces. The protection systems may be designed and used to detect and clear faults that may occur within the electric arc furnace. For example, a pair of Rogowski coils may be used to detect current at their respective locations along a conductors, and output corresponding signals to a multi-function, differential relay having multiple voltage and current inputs. By comparing the signals from the Rogowski coils, the differential relay may determine whether a fault exists at some point along the conductors and between the pair of Rogowski coils. Further, the relay may then, in response to the fault, trip a circuit breaker or other network protection device, so that the fault may be corrected.

Abstract: A high-voltage loadbreak switch operates submersed in a dielectric fluid and may be configured to switch one or more phases of power using one or more phase switches. Each phase switch may include first and second stationary contacts. The first stationary contact may be connected to a phase of a high-voltage power source. Each phase switch also may include a non-stationary contact. The non-stationary contact may be placed in a first position to electrically couple the first stationary contact to the second stationary contact, and in a second position to decouple the first stationary contact and the second stationary contact. The region of motion of the first non-stationary contact between the first position and the second position includes an arcing region. The high-voltage loadbreak switch uses a fluid circulation mechanism to improve circulation of the dielectric fluid through the arcing region.