Abstract: A power restoration system for restoring power to feeder segments in response to a fault. The system includes a reclosing device having a switch and one or more sensors for measuring current and/or voltage on the feeder, where the reclosing device performs a pulse testing process to determine circuit fault conditions. The system also includes a plurality of switching devices electrically coupled along the feeder, where each switching device includes a section switch and one or more sensors for measuring current and/or voltage on the at least one feeder. In one embodiment, each switching device recognizes predetermined pulse codes having a sequence of pulses, where the reclosing device uses the pulse testing process to generate and selectively transmit defined pulse codes on the feeder that selectively cause the section switches to change states between an open state and a closed state depending on the code.

Abstract: A transformer assembly including a transformer that is part of an underground residential power distribution circuit and that provides fault isolation and restoration. The transformer assembly includes an enclosure enclosing a primary winding and a secondary winding. The transformer assembly also includes first and second switching devices mounted to a panel of the enclosure, where each switching device includes an outer housing, a transformer interface electrically coupled to the primary winding, a connector interface electrically coupled to a first connector and a vacuum interrupter having a fixed contact and a movable contact. The fixed contact is electrically coupled to the connector interface or the transformer interface and the movable terminal is electrically coupled to the other connector interface or the transformer interface.

Abstract: A system and method for allowing islanding in an underground power distribution network when power is lost to the network. The network includes transformers having source side and load side switching devices and servicing a transformer section. The method includes detecting loss of voltage to the network, opening the source side and the load side switching devices in all of the transformers and allowing distributed power generation sources in the sections serviced by the transformers to provide power to the section. The method also includes closing one or both of the source side switching device and the load side switching device of a transformer that services a section that has power generation sources providing excess power, and closing a source side switching device or a load side switching device in an adjacent transformer to the transformer section providing excess power to provide power to the adjacent section.

Abstract: A center post assembly for eliminating sagging of a roof panel in a cabinet, where doors of the cabinet latch to the post assembly. The post assembly includes a base portion and a post portion, where one of the base portion or the post portion includes a plurality of slots and the other one of the base portion or the slot portion includes a plurality of threaded studs. The base portion further includes a first bracket and a jackscrew threaded into a threaded opening in the first bracket and the post portion further includes a second bracket, where the jackscrew engages the second bracket so that rotation of the jackscrew causes the second bracket to move relative to the first bracket so that the studs slide in the slots and increase the length of the post assembly to remove the sag.

Abstract: A current transformer assembly for harvesting power from a primary conductor, such as a power line, for operating electronics, where the assembly is secured to the conductor while the conductor is connected. The assembly includes a current transformer having a transformer structure with a central opening that accepts the primary conductor and a spindle member for accepting a current transformer magnetic tape operating as the core of the current transformer. The assembly also includes a tape carrier secured to the structure on which the transformer tape is wound, and a winding device operable to unwind the transformer tape from the tape carrier and wind the tape onto the spindle member.

Abstract: A system for automated reconfiguration of a commodity distribution system is provided. The system includes a plurality of nodes located in the distribution system and a plurality of node controllers. The node controllers control respective nodes in accordance with a first or second operating mode to affect system reconfiguration in response to a fault condition, loading, system optimization, system expansion and combinations thereof.

Abstract: A switch assembly including a switch and an interface physically coupled to the switch and configured to be physically coupled to an electrical component, such as a transformer. The switch assembly also includes an interface having electrical hardware electrically coupled to the switch and configured to be electrically coupled to the component. The switch assembly further includes a surge arrester having an insulation member, a grounding jacket formed over a portion of the insulation member and a conductor extending through the insulation member and being electrically coupled to the hardware and the grounding jacket. The interface further includes a releasable connector that is electrically coupled to the conductor and allows the surge arrester to be disconnected from the interface.

Abstract: A system and method for estimating fault current using a sliding observation window that is shorter than one cycle. The method may also include providing a pickup level that defines a current threshold for opening a switch in response to detecting the fault current; estimating the fault current from current measurement signals; accumulating time from a reset zero position during the time that the estimation of the fault current is greater than the pickup level; subtracting time from the accumulated time during the time that the estimation of the fault current is less than the pickup level after time has been accumulated from when the estimation of the fault current is greater than the pickup level; detecting the fault current if the accumulated time reaches a predetermined accumulation time; and opening the switch if the fault current is detected.

Abstract: A vacuum interrupter including a cylindrical insulator, a first end cap sealed to one end of the insulator and a second end cap sealed to an opposite end of the insulator to provide a vacuum chamber. The vacuum interrupter further includes a fixed contact stem extending through the first end cap and having a contact positioned within the chamber, and a movable contact stem extending through the second end cap and having a contact portion positioned within the chamber. A first vapor shield is formed around the fixed contact stem so as to define a gap between the fixed contact and the insulator and a second vapor shield is formed around the movable contact so as to define a gap between the movable contact and the insulator.

Abstract: An insulating rotary diaphragm for a vacuum interrupter (VI) electrical switch. The insulating diaphragm is designed for use in underground or pad-mounted VI switches where an external lever is rotated by a line worker to manually open the switch. A torsional insulating rod is coupled between a switch actuator and the external lever, and the diaphragm maintains constant contact with the insulating rod and an outer housing when the lever and rod are rotated, thus ensuring adequate isolation between the actuator and the lever. The diaphragm deforms torsionally when the lever and rod are rotated. This configuration allows the actuator to be at medium voltage, eliminates the need for a translational insulating rod between the medium voltage switch components and the lever, and thereby reduces the overall length of the VI switch.

Abstract: A switch assembly including a vacuum interrupter having a fixed contact and a movable contact, an actuator operable to move the movable contact, and a drive rod assembly coupled to the movable contact and the actuator. The drive rod assembly includes a male part and a female part where the male part is inserted into and coupled to the female part. One of the male part or the female part includes a conductor that provides an electrical connection between the male and female parts and one of the male part or the female part includes a locking ring that snap fits into a groove in the other male or female part.

Abstract: A control system and method for tie point fault interrupter and sectionalizing recloser devices in an electrical grid feeder. The technique enables automated sectionalizing reclosers equipped with three-phase current sensing and single- or three-phase voltage sensing, and able to detect pulse-closing operations, to isolate faults and restore load based on pulse count rather than requiring source re-energization and waiting for loss of voltage timers. The system includes a fault interrupter initiating a pulse-testing sequence upon detecting loss of voltage, where a number of preliminary pulses are used to distinguish transient faults from persistent faults, and pulses are counted by the sectionalizing reclosers to determine which of these devices should open.

Abstract: A method for fault location and isolation in a power distribution network, where the network includes a plurality of switching devices provided along a feeder, and at least one of the switching devices does not have voltage sensing capabilities. The method includes detecting an overcurrent event in the network from the fault and interrupting the overcurrent event by opening and then immediately locking out or subsequently reclosing and testing the fault. A count value is increased in each switching device that detected the overcurrent event. A message is sent from each of the switching devices that detected the overcurrent event and then detected the loss of voltage upstream to an upstream neighbor switching device. Current measurements in the messages, measured current by the devices and the counts values in the devices determine what devices are opened to isolate the fault.

Abstract: A system and method for clearing overcurrent in a power distribution network. The network includes a feeder, a lateral line coupled to the feeder, a lateral line current interrupting device provided where the lateral line is coupled to the feeder, a plurality of service lines coupled to the lateral line, a distribution current interrupting device provided where a service line is coupled to the lateral line and a distribution transformer provided at each location where a service line is coupled to the lateral line. The method includes setting an operating time of the lateral line interrupting device to be longer than an operating time of the distribution interrupting devices, detecting overcurrent by the lateral line interrupting device and at least one of distribution interrupting devices, and operating the at least one the distribution interrupting device and not operating the lateral line interrupting device in response to detecting the overcurrent.

Abstract: An insulator that has particular application for enclosing a switching device, such as a vacuum interrupter. The insulator includes a body having a top portion and a bottom portion, and a plurality of ring-shaped sheds extending from the body between the top portion and the bottom portion. The sheds are asymmetrical in an axial direction such that an axial dimension of the sheds at one side towards the front of the switching device is shorter than an axial dimension of the sheds at an opposite side towards the rear of the switching device. The axial dimension of the sheds uniformly increases from the one side to the opposite side.

Abstract: A switch assembly including an actuator assembly operable to magnetically latch a switch in a closed position, where the actuator assembly includes a cup member coupled to the drive rod opposite to the switch and an opening spring positioned within the cup member and being held in compression when the switch is latched closed, and where the cup member includes a central opening. The switch assembly further includes a scissor link having a first leg and a second leg pivotally attached at a pivot point, where one end of the first and second legs extend into the central opening and are rigidly attached to the cup member and an opposite end of the first and second legs extend through the cover, and where pulling the link away from the actuator assembly breaks the magnetic latch and opens the switch.

Abstract: A method for performing a low energy pulse testing in a power distribution network that causes contacts to close and then open in about one fundamental frequency cycle of current flow time and close on a voltage waveform that produces symmetrical fault current. The method includes energizing a magnetic actuator to move the actuator against the bias of a spring to move a movable contact towards a fixed contact. The method also includes de-energizing the actuator when the movable contact makes contact with the fixed contact so as to allow the spring to move the movable contact away from the fixed contact so that the amount of time that the current conducts is about one fundamental frequency cycle of the current, where energizing the magnetic actuator occurs when an applied voltage on the switch assembly is at a peak of the voltage wave so that the current is symmetric.

Abstract: A current transformer assembly for harvesting power from a primary conductor, such as a power line, for operating electronics, where the assembly is secured to the conductor while the conductor is connected. The assembly includes a current transformer having a transformer structure with a central opening that accepts the primary conductor and a spindle member for accepting a current transformer magnetic tape operating as the core of the current transformer. The assembly also includes a tape carrier secured to the structure on which the transformer tape is wound, and a winding device operable to unwind the transformer tape from the tape carrier and wind the tape onto the spindle member.

Abstract: A tamper resistant plug that has particular application for sealing a fill port in a hermetically sealed and gas-insulated tank associated with medium-voltage switchgear. The plug includes a body portion and a top annular rim defining a central recess and having an internal surface facing the recess, where the internal surface has a polygon shape with only rounded edges. In one embodiment, the polygon shape is a trilobe.

Abstract: A grounding switch for grounding a high voltage cable in underground switchgear. The switch includes a solid insulation housing and a fixed electrode extending into one end of the housing and being encapsulated in the solid insulation housing. The switch also includes a ground electrode positioned at an opposite end of the housing from the fixed electrode, an air gap formed in the solid insulation housing between the fixed electrode and the ground electrode, and a movable electrode slidable positionable within the air gap to electrically connect and disconnect the fixed electrode to and from the ground electrode. An annular shielding electrode having a ridge is electrically coupled to the fixed electrode proximate the air gap, and shapes an electric field generated by the fixed electrode to be mostly confined within the solid insulation housing.