An Uninterruptible Power Supply, UPS, comprising: an input configured to be coupled to an AC source and to receive input AC power from the AC source; a DC bus configured to be coupled to a DC source (120, 122) and to receive backup DC power from the DC source; a first output configured to be coupled to at least one AC load and to provide output AC power having an output AC voltage to the at least one AC load derived from at least one of the input AC power and the backup DC power; a second output configured to be coupled to at least one DC load and to provide via the DC bus output DC power having an output DC voltage to the at least one DC load derived from at least one of the input AC power and the backup DC power; a first bidirectional inverter coupled between the DC bus and a first transformer, the first transformer coupled to the input and configured to provide galvanic isolation between the input and the DC source; a second bidirectional inverter coupled between the DC bus and a second transformer, the second transformer coupled to the first output and configured to provide galvanic isolation between the first output and the second output; and a controller configured to operate the second bidirectional inverter to maintain the output AC voltage above a first threshold value and to operate the first bidirectional inverter to maintain the output DC voltage above a second threshold; wherein a primary winding of the first transformer is coupled between the input and the first output, and wherein a secondary winding of the first transformer is coupled to an AC interface of the first bidirectional inverter; and a primary winding of the second transformer is coupled between the first output and ground, and wherein a secondary winding of the second transformer is coupled to an AC interface of the second bidirectional inverter. an input configured to be coupled to an AC source and to receive input AC power from the AC source; a DC bus configured to be coupled to a DC source (120, 122) and to receive backup DC power from the DC source; a first output configured to be coupled to at least one AC load and to provide output AC power having an output AC voltage to the at least one AC load derived from at least one of the input AC power and the backup DC power; a second output configured to be coupled to at least one DC load and to provide via the DC bus output DC power having an output DC voltage to the at least one DC load derived from at least one of the input AC power and the backup DC power; a first bidirectional inverter coupled between the DC bus and a first transformer, the first transformer coupled to the input and configured to provide galvanic isolation between the input and the DC source; a second bidirectional inverter coupled between the DC bus and a second transformer, the second transformer coupled to the first output and configured to provide galvanic isolation between the first output and the second output; and a controller configured to operate the second bidirectional inverter to maintain the output AC voltage above a first threshold value and to operate the first bidirectional inverter to maintain the output DC voltage above a second threshold; wherein a primary winding of the first transformer is coupled between the input and the first output, and wherein a secondary winding of the first transformer is coupled to an AC interface of the first bidirectional inverter; and a primary winding of the second transformer is coupled between the first output and ground, and wherein a secondary winding of the second transformer is coupled to an AC interface of the second bidirectional inverter.