Abstract: An uninterruptible power supply (UPS) system includes a UPS unit having one or more power connectors and control signal connectors. The UPS system further includes a frame configured to removably engage and receive the UPS unit, and a bypass unit positioned within the frame and coupled to a power input and output. The bypass unit has corresponding power and control signal connectors configured to mate with respective UPS power and control signal connectors responsive to the positioning of the UPS within the frame. The bypass unit further includes a bypass switch controllable between open and closed states, which may be a normally closed relay. When the bypass switch is closed, the bypass branch shunts power around the UPS without decoupling the input from the output. A controller positioned within or outside the UPS controls the bypass switch via one or more control signal lines.

Abstract: According to one aspect, embodiments of the invention provide a UPS comprising an input to receive input AC power, a bus configured to receive backup DC power, a first output configured to provide an output AC voltage derived from at least one of the input AC power and the backup DC power, a second output configured to provide an output DC voltage derived from at least one of the input AC power and the backup DC power, a first inverter coupled between the bus and a first transformer, the first transformer coupled to the input, a second inverter coupled between the bus and a second transformer, the second transformer coupled to the first output, and a controller configured to operate the second inverter to maintain the output AC voltage above a first threshold value and to operate the first inverter to maintain the output DC voltage above a second threshold.

Abstract: According to one aspect, embodiments of the invention provide a UPS comprising an input to receive input AC power, a bus configured to receive backup DC power, a first output configured to provide an output AC voltage derived from at least one of the input AC power and the backup DC power, a second output configured to provide an output DC voltage derived from at least one of the input AC power and the backup DC power, a first inverter coupled between the bus and a first transformer, the first transformer coupled to the input, a second inverter coupled between the bus and a second transformer, the second transformer coupled to the first output, and a controller configured to operate the second inverter to maintain the output AC voltage above a first threshold value and to operate the first inverter to maintain the output DC voltage above a second threshold.