Abstract: High voltage direct current systems are provided including one or more outlets and an electronic current limiter circuit associated with the one or more outlets. The electronic current limiter circuit is configured to limit current inrush when a connector is plugged into and/or unplugged from the one or more outlets when a direct current bus associated with the one or more outlets is energized so as not to damage the connector; and/or isolate direct current faults and/or excess current draw in a load connected to the one or more outlets so as to protect the system from shutdown.

Abstract: Gate drive circuits for use with semiconductor switching devices are provided. The gate drive circuits include a gate resistor of the semiconductor switching device; a resistance control module in series with the gate resistor of the semiconductor switching device, the resistance control module being configured to provide a first resistance that controls electromagnetic interference under normal operating conditions; and a second resistance during abnormal events; and an abnormal event detector coupled to the resistance control module, the abnormal event detector configured to detect an abnormal event and send an abnormal event signal to the resistance control module responsive to detection of the abnormal event. The resistance control module is configured to provide the second resistance by shorting the resistance provided by the resistance control module responsive to the abnormal event signal to provide increased gate drive and reduced switching losses during the abnormal event.

Abstract: High voltage direct current systems are provided including one or more outlets and an electronic current limiter circuit associated with the one or more outlets. The electronic current limiter circuit is configured to limit current inrush when a connector is plugged into and/or unplugged from the one or more outlets when a direct current bus associated with the one or more outlets is energized so as not to damage the connector; and/or isolate direct current faults and/or excess current draw in a load connected to the one or more outlets so as to protect the system from shutdown.

Abstract: An uninterruptible power supply (UPS) system that includes a multiphase AC output configured to be coupled to a load, an inverter having an output coupled to the AC output and a control circuit operatively associated with the inverter and configured to cause the inverter to compensate for a phase imbalance of a load coupled to the AC output while power is being delivered to the load from an AC power source independently of the inverter.

Abstract: High density uninterruptible power supplies are provided including an enclosure and at least one uninterruptible power supply positioned in the enclosure. A battery associated with the at least one uninterruptible power supply is positioned in the enclosure. The at least one uninterruptible power supply and the associated battery are configured to provide at least thirty seconds of backup power to a load connected thereto. Related systems and power distribution units are also provided.

Abstract: An uninterruptible power supply (UPS) system that includes a multiphase AC output configured to be coupled to a load, an inverter having an output coupled to the AC output and a control circuit operatively associated with the inverter and configured to cause the inverter to compensate for a phase imbalance of a load coupled to the AC output while power is being delivered to the load from an AC power source independently of the inverter.

Abstract: Some embodiments of the inventive subject matter provide methods of operating an uninterruptible power supply (UPS) configured to provide power to a load from first and second power sources, e.g., from a utility source and a battery or other backup source. The methods include operating the UPS to momentarily provide an altered voltage waveform in coordination with a transition of the load between first and second power sources. For example, the altered voltage waveform may provide a momentarily increased voltage rate of change to compensate for a transient current demand presented by the load.

Abstract: An uninterruptible power supply (UPS) system includes an AC input configured to be coupled to an AC power source, an AC output configured to be coupled to a load, a power conversion circuit comprising a first converter circuit configured to receive power from a variably available power source, a second converter circuit coupled to the AC output, a DC link coupling the first and second converter circuits, and a switching circuit, e.g., a bypass circuit, configured to selectively couple and decouple the AC input and the AC output. The UPS system further includes a control circuit operatively associated with the power conversion circuit and the switching circuit and configured to cause concurrent transfer of power to a load at the AC output from the AC power source and the variably available power source via the switching circuit and the power conversion circuit, respectively.

Abstract: High density uninterruptible power supplies are provided including an enclosure and at least one uninterruptible power supply positioned in the enclosure. A battery associated with the at least one uninterruptible power supply is positioned in the enclosure. The at least one uninterruptible power supply and the associated battery are configured to provide at least thirty seconds of backup power to a load connected thereto. Related systems and power distribution units are also provided.

Abstract: An uninterruptible power supply (UPS) system includes a first port configured to be coupled to an AC power source and a second port configured to be coupled to a load. The system also includes a UPS circuit including a first converter circuit coupled to the first port, a second converter circuit coupled to the second port and a DC bus coupling the first converter circuit to the second converter circuit and configured to be coupled to an auxiliary power source and a third converter circuit coupled to the second port and configured to receive power from a variably available power source. A control circuit is configured to cooperatively control the UPS circuit and the third converter circuit.

Abstract: High voltage direct current systems are provided including one or more outlets and an electronic current limiter circuit associated with the one or more outlets. The electronic current limiter circuit is configured to limit current inrush when a connector is plugged into and/or unplugged from the one or more outlets when a direct current bus associated with the one or more outlets is energized so as not to damage the connector; and/or isolate direct current faults and/or excess current draw in a load connected to the one or more outlets so as to protect the system from shutdown.

Abstract: A power supply system includes an inverter circuit, for example, an inverter circuit of an uninterruptible power supply (UPS), having an output configured to be coupled to a load and an input configured to be coupled to a power source and a storage network configuration circuit configured to vary interconnections of a plurality of energy storage units of the power source, for example, plural ultracapacitors, responsive to a control input. The network configuration circuit may be operative to detect a state of the power source, such as a voltage produced thereby, and to modify parallel and serial coupling of the energy storage units responsive to the detected state. In some embodiments, the network configuration circuit may be operative to increase and/or decrease a number of the power source units connected in series across the input of the inverter circuit responsive to the detected state.

Abstract: A temperature controlled battery pack assembly includes a housing defining a battery chamber and including thermal insulation surrounding at least a portion of the battery chamber. At least one battery cell is contained in the battery chamber. The thermal insulation inhibits thermal transfer between the at least one battery cell and the surrounding environment. A thermal bridge conductor is disposed in the battery chamber and engages the at least one battery cell. The battery pack assembly further includes a thermoelectric cooler device having an inner surface and an outer surface. The thermoelectric cooler device is operable to actively transfer heat between the inner and outer surfaces using the Peltier effect. A heat sink device is in contact with or connected to the outer surface to enable thermal conduction between the outer surface and the heat sink device.

Abstract: An uninterruptible power supply (UPS) system that includes a multiphase AC output configured to be coupled to a load, an inverter having an output coupled to the AC output and a control circuit operatively associated with the inverter and configured to cause the inverter to compensate for a phase imbalance of a load coupled to the AC output while power is being delivered to the load from an AC power source independently of the inverter.

Abstract: An uninterruptible power supply (UPS) system includes an AC input configured to be coupled to an AC power source, an AC output configured to be coupled to a load, a power conversion circuit comprising a first converter circuit configured to receive power from a variably available power source, a second converter circuit coupled to the AC output, a DC link coupling the first and second converter circuits, and a switching circuit, e.g., a bypass circuit, configured to selectively couple and decouple the AC input and the AC output. The UPS system further includes a control circuit operatively associated with the power conversion circuit and the switching circuit and configured to cause concurrent transfer of power to a load at the AC output from the AC power source and the variably available power source via the switching circuit and the power conversion circuit, respectively.

Abstract: Uninterruptible power supply (UPS) systems include an AC input configured to be coupled to an AC power source, an AC output configured to be coupled to a load and a UPS circuit including a first converter circuit coupled to the AC input, a second converter circuit coupled to the AC output and a DC bus coupling the first converter circuit to the second converter circuit. The system further includes a third converter circuit having an output coupled to the AC output and an input configured to receive power from a variably available power source and a control circuit operatively associated with the UPS circuit and the third converter circuit and configured to cooperatively control the UPS circuit and the third converter circuit to selectively transfer power to the load from the AC power source and the variably available power source.

Abstract: A transformer includes a zigzag transformer comprising first, second and third magnetic cores. The transformer further includes an auxiliary winding set comprising respective pairs of series-connected windings on respective pairs of the first, second and third magnetic cores, the pairs of series-connected windings having respective first terminals connected to respective AC phases of the zigzag autotransformer and respective second terminals configured to provide respective AC output phases.

Abstract: A zigzag autotransformer includes a zigzag transformer including first, second and third magnetic cores and an auxiliary winding set including respective pairs of series-connected windings on respective pairs of the first, second and third magnetic cores, the pairs of series-connected windings having respective first terminals connected to respective AC input phase terminals of the zigzag autotransformer and respective second terminals configured to provide respective AC output phases.

Abstract: A transformer includes a zigzag transformer comprising first, second and third magnetic cores. The transformer further includes an auxiliary winding set comprising respective pairs of series-connected windings on respective pairs of the first, second and third magnetic cores, the pairs of series-connected windings having respective first terminals connected to respective AC phases of the zigzag autotransformer and respective second terminals configured to provide respective AC output phases.

Abstract: A zigzag autotransformer includes a zigzag transformer including first, second and third magnetic cores and an auxiliary winding set including respective pairs of series-connected windings on respective pairs of the first, second and third magnetic cores, the pairs of series-connected windings having respective first terminals connected to respective AC input phase terminals of the zigzag autotransformer and respective second terminals configured to provide respective AC output phases.