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.

An electrical load system includes one or more electrical loads, a power transfer switch, and an electronic control system. The power transfer switch is coupled with and can provide power to one or more electrical loads from a first power source or a second power source. The electronic control system evaluates a source impedance of the first source and controls the power transfer switch in response to the source impedance of the first source indicating a fault condition of the first power source that would interrupt power from the first power source to the one or more electrical loads prior to the fault condition disrupting power from the first power source to the one or more electrical loads.

In this uninterruptible power supply apparatus, respective phase differences between first to third carrier wave signals (CS1 to CS3) for a converter (1) and fourth to sixth carrier wave signals (CS4 to CS6) for an inverter (2) are set to 180 degrees in an inverter power feed mode and a bypass power feed mode, and respective phase differences between the first to third carrier wave signals and the fourth to sixth carrier wave signals are set to 0 degree in an overlap power feed mode. Zero-phase current (I01, I02) and circulating current (ICL) therefore can be reduced.

A static transfer switch is provided for supplying power to a load alternately from two different power sources. Preferably, switching between the two power sources occurs within one electrical cycle. In order to control inrush currents and reduce disruption during power transfers between the two power sources, switches are provided to configure which input phases are connected to the output phases.

Systems and apparatuses include an automatic transfer switch including a source pole coupled with a power source, a first load pole coupled with a first load, a second load pole coupled with a second load, a first switch selectively coupling the first load pole to the source pole, and a second switch selectively coupling the second load pole to the source pole.

A power system includes first and second power supplies, and a control circuit. The control circuit is configured to control the first power supply to regulate its output voltage at a first value, enable the second power supply, increase the output voltage of the first power supply to a second value in response to the second power supply being enabled, increase an output voltage of the second power supply to a third value, and decrease an output current of the first power supply and increase an output current of the second power supply to transition between electrically powering the load with the first power supply and electrically powering the load with the second power supply. Other example power system and methods for controlling a power transition between power supplies are also disclosed.

Apparatus and associated methods relate to automatically load matching, in time, energy physically generated and transmitted to a consumption location across at least one tracking and processing infrastructure. In an illustrative example, a load pool (LP) may be created based on energy consumed at a physical location at one or more selected time periods. A generation pool (GP) may, for example, be created based on energy generated and physically available for consumption at the physical location during the time periods. Associations may be created, for example, between measurements in the GP of energy generated and transmitted and measurements in the LP of energy consumed. The associations may be created as a function of predetermined privileges associated with the consumption location and generation locations and/or physical transmission links corresponding to the GP during the time periods. Various embodiments may advantageously determine environmental impact based on location and time-based load matching.

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.