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 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 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 end switch connected to one end of the power line and a second end switch connected to an opposite end of the power line, where each transformer includes an upstream switching device and a downstream switching device, and where source power is provided to both ends of the power line through the first and second end switches and one of the switching devices is a normally open switching device. The method includes detecting overcurrent in the network from the fault, opening certain ones of the switching devices in response thereto, detecting loss of voltage as a result of the open switching devices and opening or closing certain ones of the switching devices to isolate the fault.

An apparatus includes: a high-voltage module including: a current interrupter; an actuation system coupled to the current interrupter; a sensor system; and a terminal configured to electrically connect to an external electrical device. The apparatus also includes: a user interface; and an electrically insulating assembly between the user interface and the high-voltage module. In operational use, the user interface is grounded and the high-voltage module is at a system voltage.

A switching apparatus comprises: a plurality of parallel-connected current-conductive branches, each current-conductive branch including at least one respective gas tube switch; and a switching control unit configured to control the turn-on of the gas tube switches in a switching order so that the flow of current in the switching apparatus is controlled to switch between the current-conductive branches, wherein the switching order of the turn-on of the gas tube switches is arranged so that only one of the current-conductive branches is carrying the current during each turn-on cycle of the switching apparatus.

A switchgear or control gear includes: at least one first compartment; at least one second compartment; a plurality of main switchgear or control gear components including a main busbar system, a three position linear or rotational movement disconnector, a circuit breaker, and at least a first part of an insulated cable connection; and a plurality of auxiliary switchgear or control gear components including a disconnector drive and a circuit breaker drive. The plurality of main switchgear or control gear components are housed in the at least one first compartment. The plurality of auxiliary switchgear or control gear components are housed in the at least one second compartment. When one or more of the plurality of main switchgear or control gear components is energized, the at least one first compartment is hermetically sealable or maintainable at an internal air pressure greater than ambient air pressure.

A smart, self-feeding fuse with current detection and communication capabilities for use in overhead medium voltage electrical distribution networks (15 kV to 34 kV). The device is configured to detect transient or permanent electric faults (sensor), and/or to be used as a communication device (gateway) that preserves the main protection function of the fuse element. The device is assembled on a base fuse and is simply installed by using a maneuver pole, similarly to the installation of a conventional fuse tube. The invention is self-fed by a high output current transformer with the help of photovoltaic cells, using a supercapacitor bank as the only power storage element.

The invention relates to a switching device for a MV electric power distribution network. The switching device comprises electric contacts, which are electrically connectable to a conductor of said electric power distribution network, and a control unit. The switching device comprises signalling means emitting visible light externally to said switching device, said signalling means being controlled by said control unit.