American Power Conversion Corporation

Schneider Electric It Corporation

Emanuel Landsman

Vishwas Mohaniraj Deokar

Namwook Paik

Fred William Rodenhiser

David E Reilly

Michael J Ingemi

Jeffrey Curtis

James H Donalds

Jamie Donalds

Steve Williams

Stephen G Williams

According to one aspect, embodiments herein provide a UPS comprising a UPS input configured to be coupled to an AC power source and to receive input AC power, an interface configured to be coupled to a DC power source and to receive backup DC power, a UPS output configured to provide output power derived from at least one of the input AC power and the backup DC power to a load, a converter comprising a converter input coupled to the UPS input, a converter output, a first converter path coupled between the converter input and the converter output, and a second converter path coupled between the converter input and the converter output, and a controller configured to operate the first converter path and the second converter path to convert the input AC power into DC power and provide the DC power to the converter output.

System and method to reduce converter emissions

At least one aspect is directed to a transfer switch including a first input to couple a first multiphase low voltage electrical supply to the transfer switch, and a second input to couple a second multiphase low voltage electrical supply to the transfer switch. The transfer switch also includes a first set of switches in electrical communication with the first input and a second set of switches in electrical communication with the second input. A control module monitors and controls operation of both the first set of switches and the second set of switches to detect a malfunction of any switches included in at least one of the first set of switches and the second set of switches and prevent the first input from being placed in electrical communication with the second input.

Apparatus and method for preventing an electrical backfeed

At least one aspect is directed to an uninterruptible power supply that includes a first input to receive a first input voltage from a first voltage source, a second input to receive a second input voltage from a second voltage source, and a boost circuit coupled to the first input and the second input. The boost circuit is configured to provide a positive output DC voltage and a negative output DC voltage derived from at least one of the first input voltage and the second input voltage. The uninterruptible power supply is configured such that in a back-up mode of operation, the negative output DC voltage is derived from the second input voltage using a circuit that includes at least two controlled switches coupled in series.

Method and apparatus for providing uninterruptible power

Embodiments of the present invention are directed to an uninterruptible power supply for providing AC power to a load. In embodiments of the present invention, the uninterruptible power supply includes an input to receive AC power from an AC power source, an output that provides AC power, a DC voltage source that provides DC power, the DC voltage source having an energy storage device, an inverter operatively coupled to the DC voltage source to receive DC power and to provide AC power. The inverter includes first and second output nodes to provide AC power to the load, first and second input nodes to receive DC power from the DC voltage source, a resonant element having a first terminal and a second terminal, the second terminal being electrically coupled to the first output node, a first switch electrically coupled between the first terminal of the resonant element and the first input node, wherein during a first time period, the first switch is controlled to allow an electrical current path to connect the resonant element to the capacitive element, an electrical current of the path storing energy in the resonant element and charging the capacitive element to a first voltage level, and during a second time period, the first switch is controlled to block the current path to cause the stored energy in the resonant element to further charge the capacitive element to a second voltage level during the second time period. The uninterruptible power supply further includes a transfer switch constructed and arranged to select one of the AC power source and the DC voltage source as an output power source for the uninterruptible power supply.

Method and apparatus for converting a DC voltage to an AC voltage

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Lexington, MA, United States of America

Emanuel Landsman