A power supply control apparatus includes: a first system capable of supplying electric power from a first power supply to a first load; a second system capable of supplying electric power from a second power supply to a load group including a second load and a third load having consumed electric power smaller than that of the second load; a plurality of load switches as defined herein; and a control unit configured to control the load switches so that backup control performed by the second system is executed by the electric power supply from the second power supply, in a case where an occurrence of a ground fault in the first system is detected, and when the control unit inspects as to whether the backup control can be executed, the control unit connects the load switch corresponding to the third load of the load group to execute the inspection.

Aircraft power distribution systems and methods for regulating a system voltage in aircraft power distribution systems are described. An example system includes a first generator, a first power feeder, a second power feeder, a first load, a second load, and a plurality of contactors. The first power feeder and the second power feeder are coupled in parallel between the first generator and a power panel. The first load is coupled to the first power feeder, and the second load is coupled to the second power feeder. The plurality of contactors is configurable to transfer power in a first direction from the first generator to both the first load and the second load during a first mode of operation, and configurable to transfer power in a second direction from the power panel to the first load or the second load during a second mode of operation.

An electricity backfeed protection assembly is beneficially installed between a main circuit breaker panel of a structure or dwelling, and a utility meter measuring electricity delivered to the structure or dwelling by a utility provider or other primary power source. The electricity backfeed protection assembly includes a contactor having a coil. A contact protector device is electrically connected to the coil of the contactor. The electrical backfeed protection assembly automatically prevents electricity from a secondary power source (including, without limitation, a portable generator) from backfeeding into supply lines of a primary power source (such as utility lines or equipment).

Disclosed is an uninterruptible power supply system, including a sub power supply device configured to supply or cut off sub input power to a load device; a battery configured to supply or cut off battery input power to the load device; and an uninterruptible power supply device that is electrically connected to the sub power supply device and the battery, and when main input power is selectively received and supplied to the load device or the battery input power is selectively received and supplied to the load device, determines whether the main input power and the battery input power are within a predetermined reference main input power range and reference battery input power range, and when the main input power and the battery input power are outside of the reference main input power range and the reference battery input power range, receives the sub input power and supplies the power to the load device.

This application discloses a non-current equalization UPS apparatus, a current distribution method, and a parallel UPS system. The current distribution method may be applied to any UPS apparatus in a parallel UPS system. A current proportion of a first current output by the any UPS apparatus in a total output current of the parallel UPS system is positively related to a capacity proportion of an available battery capacity of a battery string correspondingly connected to the any UPS apparatus in a total available battery capacity of the parallel UPS system. Therefore, a system backup time of the parallel UPS system can be prolonged, and resource utilization of a battery string with a large available battery capacity can be improved.

According to one aspect, embodiments herein provide a UPS comprising a first input configured to receive input power, a second input configured to receive backup power, an output, a bypass line selectively coupled between the first input and the output via a bypass switch, wherein in a bypass mode of operation, the bypass switch is closed and the input power is provided directly to the output, an inverter comprising an input configured to receive at least one of the input power and the backup power and an output selectively coupled to the output of the UPS via an inverter switch, wherein in an online mode of operation, the inverter switch is closed and the inverter converts the input power into the output AC power, and means for operating the inverter to force commutate current in the bypass line after a transition from the bypass to the online mode of operation.

A method of operating a static transfer switch is provided. The method includes monitoring a voltage waveform for each phase of first and second power sources, and calculating flux for each phase of the power sources. The method also includes determining (i) a first flux difference between the respective flux of the first phases of the first and second power sources, (ii) a second flux difference between the respective flux of the second phases of the first and second power sources, and (iii) a third flux difference between the respective flux of the third phases of the first and second power sources. The method further includes turning off a third solid-state switch to disconnect the third phase of the first power source from a load, in response to the controller determining that the third flux difference is greater the first and second flux differences.

One or more embodiments of the present invention relates to an energy supply circuit for a CT system. The energy supply circuit comprises a stationary energy distribution device, a co-rotating bias voltage supply device, a standard energy supply path having an energy transmission device between the stationary energy distribution device and the co-rotating bias voltage supply device and an alternatively connectable service energy supply path having a voltage protection device. A computed tomography system is also described. Further, a production method for producing an energy supply circuit for a CT system is described. In addition, a method for operating a CT system is described.

A power device, system and method. The device may include a housing defining a first support operable to support a first battery pack, and a second support operable to support a second battery pack; a circuit selectively electrically connecting the first battery pack and the second battery pack in series, the circuit including an output terminal to provide an output voltage to a powered device, a first bypass portion operable to selectively electrically disconnect the first battery pack from the circuit, and a second bypass portion operable to selectively electrically disconnect the second battery pack from the circuit; and a boost converter electrically connected to the circuit and operable to boost a voltage at the output terminal.

A reserve power supply system for providing a supplemental source of electrical power to a main power source. The system includes a backup battery and a switch that can be controlled to couple the backup battery to the main power source when reserve power is needed. The system also includes a sensor to detect when the backup battery should be engaged and a system control unit.