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.

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.

A switch assembly that is part of a transformer in an underground residential power distribution circuit and that provides fault isolation and restoration. The switch assembly includes first and second switching devices each having an outer housing, a transformer interface electrically coupled to the transformer, a connector interface electrically coupled to a first connector and a first vacuum interrupter having a fixed contact and a movable contact, where the fixed contact is electrically coupled to the connector interface and the movable contact is electrically coupled to the transformer interface. A control board controls the first and second switching devices, where the control board is responsive to voltage signals from capacitors in the first and second switching devices.

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.

A system includes an electrical apparatus configured to monitor or control one or more aspects of an electrical power distribution network; and a control system including more than one electronic processor, where the electronic processors are configured to cause the control system to interact with the electrical apparatus, an interaction between the control system and the electrical apparatus including one or more of the control system providing information to the electrical apparatus and the control system receiving information from the electrical apparatus, and if some of the electronic processors are unable to cause the control system to interact with the electrical apparatus, at least one of the other electronic processors is able to cause the control system to interact with the apparatus.

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.

A switchgear apparatus configured for operation at voltages up to 72.5 kV includes a vacuum interrupter assembly including a vacuum bottle having an upper portion and a lower potion, a sleeve surrounding the vacuum bottle, a dielectric material surrounding the sleeve, a first terminal electrically coupled to the upper portion of the vacuum interrupter assembly, and an interchange coupled to a lower portion of the vacuum interrupter assembly. The dielectric material is molded around the sleeve and around at least a portion of the first terminal or the interchange. In some embodiments, the sleeve is molded around the vacuum bottle. In other embodiments, the sleeve may be otherwise positioned (i.e., by sliding a pre-formed sleeve) around the vacuum bottle.

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.

A fault protection system for providing protection from fault current for components and devices on a lateral line proximate to a distribution transformer in a power distribution network. The system includes a single-phase recloser having a vacuum interrupter that is controlled by a controller. In one embodiment, the recloser has an insulating body that is molded in combination with an insulating body of a bushing that is connected to the distribution transformer. In this embodiment, the controller can be powered by a current transformer within the recloser. In another embodiment, the recloser is mounted to a utility pole separate from the distribution transformer, where the controller is powered by the low voltage side of the transformer and the current transformer is eliminated. An isolated power supply is provided between the transformer and the controller to provide voltage isolation.

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.