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.

The present specification relates to an uninterruptible power supply device, an uninterruptible power supply system and a method for controlling the uninterruptible power supply system, and relates to a power supply device comprising a circuit breaker for switching connection to a power bus, thereby controlling the reception and supply of the power by opening and closing the circuit breaker according to various situations occurring in a system, a power supply system and a method for controlling the power supply system.

Electrical devices are connected to a DC voltage power supply grid being connected to a power source and having a supply voltage. Protection devices protect the electrical devices against an unintentional overcurrent sensed by a sensor unit. The protection devices disconnect the electrical devices from the DC voltage power supply grid when an overcurrent is detected. A pulse circuit having a capacitor with a semiconductor switching element connected in series with the capacitor is connected to respective inputs of the protection devices and supplies an amount of electric charge when a voltage dip occurs, wherein the amount of supplied electric charge is determined based on the detected overcurrent and a predetermined time period.

A system and method for controlling an operation of devices in a power distribution network. The method determines that there is a power loss in the network as a result of a fault and one or more teams is not receiving power and performs a switching process in switching devices to prevent fault current from flowing to the fault. The method initiates a power restoration process to control the open and closed status of switching devices to isolate the fault and performs the power restoration process by the leader device in a division that the fault is occurring that includes opening and closing switching devices so that power is provided to all of the teams except the team that the fault is in. The method reconfigures the divisions based on which switching devices are now open and selects new leader devices based on the reconfiguration of the divisions.

A system and method for restoring power in a power distribution network. The network includes at least two power sources, at least one feeder and a plurality of switching devices positioned along the at least one feeder and being in communications with each other. The method determines that one or more of network sections is not receiving power, and determining a plurality of possible power restoration solutions that identify what sections each of the power sources that are available to provide power can provide power to based on a power capacity of the sources and a load requirement of the sections. The method applies predetermined selection criteria to the plurality of possible solutions to determine which of the possible solutions will be used as an actual solution, and selectively switches the switching devices between open and closed states to apply the actual solution.

A system and method for restoring power in a closed-loop power distribution network. The network includes at least two power sources, at least one feeder and a plurality of switching devices positioned along the at least one feeder and being in communications with each other. The method performs a radial restoration process for restoring power and then determines that at least one of the sections is not receiving power after the radial restoration process has been performed. The method estimates power flow through each switching device and determines an available power capacity from each switching device. The method then determines if the unpowered sections can be powered by any of their neighbor and non-neighbor devices. The method virtually closes the switching devices to power the unpowered sections and updates the estimation of power flow through each switching device and determination of available power capacity from each switching device.

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.

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.