US 2016/0111916 A1Published application

Uninterruptible power supply control

AssigneeSchneider Electric It Corporation

InventorsIndra Prakash, Sriya Dupakuntla

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Abstract

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.

Claims20

Dependent claims

An Uninterruptible Power Supply (UPS) comprising:

a first input configured to be coupled to an AC source and to receive input power;
a second input configured to be coupled to a backup power source to receive backup power;
an output configured to be coupled to a load and to provide output AC power to the load derived from at least one of the input power and the backup power;
a bypass line selectively coupled between the first input and the output via a bypass switch, wherein the bypass switch is configured to close in a first mode of operation, coupling the first input of the UPS to the output of the UPS via the bypass line, and to open in a second mode of operation, decoupling the first input of the UPS from the output of the UPS;
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 the inverter switch is configured to close in the second mode of operation, coupling the output of the inverter to the output of the UPS, and to open in the first mode of operation, decoupling the output of the inverter from the output of the UPS;
and
an inverter controller coupled to the inverter and to the bypass line, wherein the inverter controller is configured, in the second mode of operation, to monitor current in the bypass line and, in response to a determination that the current in the bypass line is greater than a threshold level, to operate the inverter to provide current to the output of the UPS having a direction opposite to a direction of the current in the bypass line.

4 more elements

A method for operating a UPS, the UPS having an input, an output, a bypass line selectively coupled between the input and the output, and an inverter, the method comprising:

monitoring input AC power provided to the input of the UPS from an AC power source;
determining whether the input AC power provided to the input is acceptable;
in response to a determination that the input AC power is acceptable, providing the input AC power to the output of the UPS via the bypass line;
in response to a determination that the input AC power is not acceptable, severing the connection between the input and the output via the bypass line and enabling the inverter;
monitoring current in the bypass line;
determining, in response to monitoring, whether the current in the bypass line exceeds a threshold level;
and
in response to a determination that current in the bypass line exceeds the threshold level, operating the inverter to provide an output current to the output of the UPS having a direction opposite to a direction of the current in the bypass line.

5 more elements

Dependencies are inferred from the claim text.