Abstract: A mounting bracket for securing a control unit that controls a bushing well interrupter device provided within a transformer enclosure associated with an underground loop circuit. The mounting bracket includes a support portion configured to hold the control unit and a mounting portion coupled to the mounting portion, where the mounting portion including a hook portion configured to hook onto one terminal in the enclosure and a notch portion configured to rest against another terminal in the enclosure.

Abstract: An energy harvesting circuit for harvesting energy from a medium voltage power line. The energy harvesting circuit includes an input capacitor electrically coupled to the power line and storing power therefrom, and a flyback converter including a primary coil and a secondary coil. The harvesting circuit further includes a switching circuit electrically coupled in series with the primary coil and being operable to electrically connect and disconnect the input capacitor to and from the primary coil, where the switching circuit includes an input voltage regulation feedback circuit for regulating an input voltage provided to the switching circuit from the input capacitor. The harvesting circuit also includes an output capacitor electrically coupled to the secondary coil and the actuator, where the output capacitor is charged by the secondary coil when the switching circuit is closed to provide power to an actuator to close a vacuum interrupter.

Abstract: A series Z-source circuit breaker including a semiconductor switch that breaks source power being provided to a load in response to overcurrent. An electromechanical switch is electrically coupled in parallel with the semiconductor switch, a first capacitor is electrically coupled to an output side of the semiconductor switch, a second capacitor is electrically coupled in parallel with the semiconductor switch, and a delay circuit is electrically coupled in series with the first capacitor. The semiconductor switch is in an open position and the electromechanical switch is in a closed position when overcurrent is not present. Upon detection of overcurrent the semiconductor switch is closed, the electromechanical switch is opened and the delay circuit is controlled to delay when reverse bias current is provided from the first capacitor to the semiconductor switch to prevent source power from being provided to the load to give the electromechanical switch time to open.

Abstract: An actuator assembly including a first actuator having a first magnetically actuated plunger and a first latching plate, where the first plunger is operable to be magnetically latched to the first latching plate. The actuator assembly further includes a second actuator coupled to and axially aligned with the first actuator. The second actuator includes a second magnetically actuated plunger, a second latching plate, a sleeve positioned within and extending from the second plunger and being rigidly secured to the first plunger, and a tolerance spring wrapped around the sleeve. The second plunger is operable to be magnetically latched to the second latching plate, where latching of the second plunger causes the tolerance spring to compress and provide additional latching force of the first plunger to the first latching plate.

Abstract: A system and method for calibrating a capacitor voltage sensor that measures voltage on a power line coupled through a switch to a primary coil of a transformer. The method includes measuring a control voltage on a secondary coil of the transformer and measuring voltage on the capacitor sensor when the switch is known to be closed. The method identifies a calibration factor that when multiplied by the measured voltage on the capacitor sensor when the switch is closed makes the measured voltage on the capacitor sensor substantially equal to the control voltage. The method subsequently measures voltage on the capacitor sensor when the switch is open or closed during operation of the transformer, and multiplies the subsequently measured voltage on the capacitor sensor when the switch is open or closed by the calibration factor to obtain a measured voltage.

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 method for isolating a fault in an underground power distribution network. The network includes a power line, a plurality of transformers electrically coupled to and positioned along the power line, a first recloser connected to one end of the power line and a second recloser connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where power is provided to both ends of the power line through the first and second reclosers and one of the switching devices is a normally open switching device. The method includes detecting overcurrent by some of the switching devices, detecting loss of voltage by some of the switching devices and sending clear to close messages to some of the switching devices to open and close certain ones of the switching devices to isolate the fault.

Abstract: A power restoration system comprising a feeder, a plurality of power sources available to provide power to the feeder, a plurality of normally closed reclosing devices electrically coupled along the feeder, at least one normally open recloser electrically coupled to the feeder, and a plurality of normally closed switches electrically coupled along the feeder between each adjacent pairs of normally closed reclosing devices. Each switch is assigned a position code having a value for each of the plurality of power sources that determines when the switch will open in response to the fault current and which power source the switch is currently receiving power from, where timing control between the reclosing devices and the switches allows the switch to be selectively opened to isolate the fault within a single feeder section between each pair of adjacent switches or between each switch and a reclosing device.

Abstract: A switch assembly including a switch and a high impedance element used for energy harvesting purposes that are connected to a power line and assembly electronics. The high impedance element has higher impedance than the switch so that current flows through the switch from the power line when the switch is closed and through the high impedance element from the power line when the switch is open. The switch assembly also includes a current sensing device, such as a current sensing resistor, electrically coupled in series with the high impedance element and the electronics. By measuring the current flow using the current sensing device, it is possible to infer the voltage across the high impedance element since its impedance is known. This voltage can be used to provide point on wave closing of the switch and to determine the line voltage magnitude.

Abstract: A method for identifying a location of a fault in an electrical power distribution network that includes identifying an impedance of an electrical line between each pair of adjacent utility poles, measuring a voltage and a current of the power signal at a switching device during the fault, and estimating a voltage at each of the utility poles downstream of the switching device using the impedance of the electrical line between the utility poles and the measured voltage and current during the fault. The method calculates a reactive power value at each of the utility poles using the estimated voltages, where calculating a reactive power value includes compensating for distributed loads along the electrical line that consume reactive power during the fault, and determines the location of the fault based on where the reactive power goes to zero along the electrical line.

Abstract: A communication-based permissive protection method for protecting an electrical power distribution network from a fault. The network includes a power source, an electrical line and a plurality of fault interrupters, where the fault interrupters are operable to prevent current flow in response to the fault. The method includes detecting the fault by each fault interrupter that is between the fault and the power source, and sending a drop of voltage message from each fault interrupter that doesn't detect the fault, but does detect a drop of voltage as a result of the fault to its immediate upstream fault interrupter. The method opens the fault interrupter that both detects the fault and receives a drop of voltage message from all of the fault interrupters immediately downstream of that fault interrupter.

Abstract: A method for separating welded contacts in a magnetically actuated switch assembly that includes providing multiple actuator hammer blows to the contacts. The method includes causing the contacts to close using, for example, a manual actuation device and detecting a high current condition that occurs when the contacts are closed. The method further includes electrically actuating the actuator to open the contacts in response to detecting the high current condition and determining that the contacts have not opened in response to the actuator being actuated because they are welded together. The method also includes electrically actuating the actuator to close the contacts when it is determined that they are welded together and again electrically actuating the actuator to open the contacts.

Abstract: A power restoration system comprising a feeder, a plurality of power sources available to provide power to the feeder, a plurality of normally closed reclosing devices electrically coupled along the feeder, at least one normally open recloser electrically coupled to the feeder, and a plurality of normally closed switches electrically coupled along the feeder between each adjacent pairs of normally closed reclosing devices. Each switch is assigned a position code having a value for each of the plurality of power sources that determines when the switch will open in response to the fault current and which power source the switch is currently receiving power from, where timing control between the reclosing devices and the switches allows the switch to be selectively opened to isolate the fault within a single feeder section between each pair of adjacent switches or between each switch and a reclosing device.

Abstract: A system and method for representing the topology of a power distribution network, where the network includes at least one power source, a feeder and a plurality of switching devices positioned along the feeder. The method includes providing a device list in each switching device that includes a local device index of each of the switching devices, a local team index of the team on an X-side of each of the switching devices, the local team index of the team on a Y-side of each of the switching devices and device specific data, where the X and Y-sides of the switching device is the physical orientation of the device when it is installed, and providing a team list in each switching device that includes the local team index of each of the teams, the local device indices of the switching devices on each team and team specific data.

Abstract: A system and method for determining when an electronic interrupting device will open in response to detecting overcurrent, where the interrupting device protects a transformer in a power distribution network. The method includes obtaining a time/current through fault protection curve that is defined by a plurality of time/current points for the transformer that identifies when the transformer may experience thermal or mechanical damage in response to a certain current flow over a certain time in the transformer windings, selecting a time multiplier, and determining an operating curve for the interrupting device by multiplying the multiplier and a time portion of each of the plurality of time/current points on the through fault protection curve, where the operating curve identifies when the interrupting device will open in response to a certain current flow over a certain time.

Abstract: A system and method for determining loads throughout a power distribution network having a plurality of switching devices provided along a feeder. The method includes measuring the current and/or voltage on one or both sides of the switching devices and calculating a power flowing through each of the switching devices and a load in each section using the current and/or voltage measurements at predetermined sample times. The method further includes storing a plurality of recorded current/voltage measurements or calculated powers flowing through each device for consecutive sample times. The method then determines a median load from the measurements and power flows and calculates a load in each of network sections.

Abstract: A system and method for disseminating information and data throughout a power distribution network. A timer is set in each of the network endpoint switching devices that expire at the same time. A message is sent from each endpoint device to its neighbor switching device(s) when the timer expires that includes data about the endpoint switching device, and the message is received from the endpoint switching device at a receiving side of the neighbor switching devices. A message is sent from the neighbor switching devices to their neighbor switching devices at a sending side of the neighbor switching devices that includes data about the endpoint switching device and the neighbor switching device of the endpoint switching device. The messages are continually sent through the switching devices in this manner until all of the switching devices have the data about all of the other switching devices in a division or feeder.

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: A structure for closing an actuator in a magnetically actuated switch assembly, where the actuator includes an armature and a winding, and the switch assembly includes a manual actuation device coupled to one end of the armature and a movable terminal in a vacuum interrupter coupled to an opposite end of the armature. The structure includes commencing a closing operation of the actuator using the manual actuation device to move the armature towards a closed latch position, detecting that the actuator is being manually closed, and energizing the winding to assist moving the armature to the closed latch position when the armature gets to a predetermined distance from the closed latch position.

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.