Abstract: A system and method for adaptive impedance protection in a power network. The method includes determining a measured impedance in an upstream interrupting device, determining an impedance set point in the upstream interrupting device, and identifying a predetermined percentage of the impedance set point. The method also includes determining if the measured impedance falls below the predetermined percentage, determining whether a change in a measured current value on the power line is less than a threshold change value in a downstream interrupting device, and sending the determination of whether the change in the measured current value is less than the threshold change value from the downstream interrupting device to the upstream interrupting device. The upstream interrupting device is opened if the measured impedance falls below the predetermined percentage of the impedance set point and the change in the measured current value is less than the threshold change value.

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.

Abstract: An electrical device including a first cylindrical capacitor, a first terminal electrically coupled to one end of the first capacitor, a first electrical line electrically coupled to the first terminal and a first annular conductive end shield formed over the first terminal and being electrically coupled to the first terminal and the one end of the first capacitor, where the first end shield has a greater diameter than the diameter of the first capacitor. The device also includes a second cylindrical capacitor, a second terminal electrically coupled to one end of the second capacitor, a second electrical line electrically coupled to the second terminal and a second annular conductive end shield formed over the second terminal and being electrically coupled to the second terminal and the one end of the second capacitor, where the second end shield has a greater diameter than the diameter of the second capacitor.

Abstract: A system and method for determining if a fault condition exists in an electrical network. The method includes determining that a fault protection device has been opened and monitoring a voltage angle of a voltage waveform across a vacuum gap switching arrangement if the fault protection device is open, where the vacuum gap switching arrangement includes at least one vacuum gap switching element. The method also includes triggering a breakdown of a vacuum gap in the at least one vacuum gap switching element when the voltage angle corresponds to a predetermined switching angle to enable a temporary current flow through the vacuum gap switching arrangement, measuring the current flow through the vacuum gap switching arrangement, and determining whether the fault condition exists based at least in part on the measured current flow.

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 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.

Abstract: A switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a transformer interface for coupling the device to the transformer and a connector interface for coupling the device to a connector. The device also includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to the connector interface and the movable terminal is electrically coupled to the transformer interface. A control rod is coupled to the movable terminal, an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. A capacitor is electrically coupled to the fixed terminal, and provides an interface for power line communications signals, voltage sensing, help determine power flow direction and help determine the distance to a fault.

Abstract: A capacitive network for use in a voltage sensor includes a first conductor shaped to form a boundary that separates a first interior space and a first exterior space; a second conductor shaped to form a boundary that encircles a second interior space and separates the second interior space from a second exterior space; a third conductor disposed in the second interior space and having a line of sight to the first conductor through an opening in the second conductor; and an external insulator formed around the first conductor and the second conductor in the first exterior space and the second exterior space. A first capacitance is formed between the first conductor and the third conductor, a second capacitance is formed between the second conductor and the third conductor, and conductive material that may collect on the external insulator has negligible effect on the first capacitance and the second capacitance.

Abstract: A capacitive voltage sensor that has particular application to be molded into an insulating body of a switch. The voltage sensor includes an annular electrode assembly having a grounded electrode including an inner ring and an outer ring defining a space therebetween, and a sensing electrode positioned in the space and being substantially surrounded by the inner and outer rings. The body is formed around the electrode assembly and a cylindrical center conductor extends through the electrode assembly. Capacitive coupling is provided between the sensing electrode and the center conductor by one or more openings in the inner ring, such as a single round hole, a slot or a plurality of symmetrically disposed round holes or slots. The inner and outer rings can be attached at one end so that the grounded electrode is a single piece or the rings can be separate rings electrically coupled together by conductive screws.

Abstract: A triggered vacuum gap (TVG) device that has application as a closing switch for synchronized closing in distribution and transmission power systems. The TVG device controllably sustains a current arc in the device through initial current zeros created by power system transients and, thereby, prevents premature interruption of the closing operation. The TVG device includes main electrodes defining a vacuum gap therebetween and a triggering electrode providing a triggering gap between one main electrode and the triggering electrode. The TVG device also includes a triggering circuit having a high voltage impulse source that supplies a fast rising impulse voltage to the one main electrode and the triggering electrode for creation of a plasma to provide an initial breakdown of the triggering gap and a low voltage unidirectional current source that supplies current to the one main electrode and the triggering electrode once the first triggering gap breakdown has occurred.

Abstract: A fault interrupting switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to a transformer interface and the movable terminal is electrically coupled to a connector interface. A control rod is coupled to the movable terminal and an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. An electronics assembly electrically is coupled to the movable terminal, and includes a high voltage capacitor and an energy storage capacitor, where the high voltage capacitor provides power to operate the actuator when the vacuum interrupter is open and the energy storage capacitor provides power to the electronics assembly when the vacuum interrupter is closed.

Abstract: A switching device that is part of a transformer in an underground residential power distribution circuit and provides fault isolation and restoration. The switching device includes a transformer interface for coupling the device to the transformer and a connector interface for coupling the device to a connector. The device also includes a vacuum interrupter having a fixed terminal and a movable terminal, where the fixed terminal is electrically coupled to the connector interface and the movable terminal is electrically coupled to the transformer interface. A control rod is coupled to the movable terminal, an actuator assembly is coupled to the control rod and is operable to move the control rod to open and close the vacuum interrupter. A capacitor is electrically coupled to the fixed terminal, and provides an interface for power line communications signals, voltage sensing, help determine power flow direction and help determine the distance to a fault.

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 magnetic module in a circuit interrupting system is configured to generate a blow-on force that pushes a moving contact toward a stationary contact. The magnetic module includes: a coil conductor having an opening through which a moving stem of the moving contact may move, wherein the coil conductor is electrically connected to the moving stem and a first auxiliary conductor, wherein the coil conductor is configured to allow current to flow from the moving stem to the first auxiliary conductor; a plunger attached to an end of the moving stem; and a first magnetic core shaped to fit around a first section of the coil conductor, wherein the first magnetic core is configured, when current flows through the coil conductor to the first auxiliary conductor, to become magnetized, attract the plunger toward the magnetic core, and cause the moving stem of the moving contact to move toward the stationary contact.

Abstract: A switching module for use in a high voltage switch includes: a vacuum interrupter (VI), an elastomeric insulating sleeve disposed around the VI; an insulating housing molded around the VI and the sleeve; and a pair of grading capacitors. Each grading capacitor includes an inner and an outer electrode while insulation between the electrodes is solid insulation of the housing molded at the time when the housing is molded. One of the electrodes is galvanically connected to the fixed contact through a first terminal in the switching module and the other electrode is galvanically connected to the moving contact through a second terminal in the switching module. The capacitance of the first grading capacitor is substantially equal to the capacitance of the second grading capacitor.

Abstract: A system and method for determining if a fault condition exists in an electrical network. The method includes determining that a fault protection device has been opened and monitoring a voltage angle of a voltage waveform across a vacuum gap switching arrangement if the fault protection device is open, where the vacuum gap switching arrangement includes at least one vacuum gap switching element. The method also includes triggering a breakdown of a vacuum gap in the at least one vacuum gap switching element when the voltage angle corresponds to a predetermined switching angle to enable a temporary current flow through the vacuum gap switching arrangement, measuring the current flow through the vacuum gap switching arrangement, and determining whether the fault condition exists based at least in part on the measured current flow.

Abstract: A capacitive voltage sensor that has particular application to be molded into an insulating body of a switch. The voltage sensor includes an annular electrode assembly having a grounded electrode including an inner ring and an outer ring defining a space therebetween, and a sensing electrode positioned in the space and being substantially surrounded by the inner and outer rings. The body is formed around the electrode assembly and a cylindrical center conductor extends through the electrode assembly. Capacitive coupling is provided between the sensing electrode and the center conductor by one or more openings in the inner ring, such as a single round hole, a slot or a plurality of symmetrically disposed round holes or slots. The inner and outer rings can be attached at one end so that the grounded electrode is a single piece or the rings can be separate rings electrically coupled together by conductive screws.

Abstract: A switching module for use in a high voltage switch includes: a vacuum interrupter (VI), an elastomeric insulating sleeve disposed around the VI; an insulating housing molded around the VI and the sleeve; and a pair of grading capacitors. Each grading capacitor includes an inner and an outer electrode while insulation between the electrodes is solid insulation of the housing molded at the time when the housing is molded. One of the electrodes is galvanically connected to the fixed contact through a first terminal in the switching module and the other electrode is galvanically connected to the moving contact through a second terminal in the switching module. The capacitance of the first grading capacitor is substantially equal to the capacitance of the second grading capacitor.

Abstract: A magnetic module in a circuit interrupting system is configured to generate a blow-on force that pushes a moving contact toward a stationary contact. The magnetic module includes: a coil conductor having an opening through which a moving stem of the moving contact may move, wherein the coil conductor is electrically connected to the moving stem and a first auxiliary conductor, wherein the coil conductor is configured to allow current to flow from the moving stem to the first auxiliary conductor; a plunger attached to an end of the moving stem; and a first magnetic core shaped to fit around a first section of the coil conductor, wherein the first magnetic core is configured, when current flows through the coil conductor to the first auxiliary conductor, to become magnetized, attract the plunger toward the magnetic core, and cause the moving stem of the moving contact to move toward the stationary contact.

Abstract: A capacitive network for use in a voltage sensor includes a first conductor shaped to form a boundary that separates a first interior space and a first exterior space; a second conductor shaped to form a boundary that encircles a second interior space and separates the second interior space from a second exterior space; a third conductor disposed in the second interior space and having a line of sight to the first conductor through an opening in the second conductor; and an external insulator formed around the first conductor and the second conductor in the first exterior space and the second exterior space. A first capacitance is formed between the first conductor and the third conductor, a second capacitance is formed between the second conductor and the third conductor, and conductive material that may collect on the external insulator has negligible effect on the first capacitance and the second capacitance.