Abstract: A front-end converter in an uninterruptible power supply system is described. In an exemplary design, a front-end converter includes a boost circuit having first and second inputs, positive, negative, and neutral output nodes, an inductor, AC inputs, a battery, and first and second devices. The boost circuit is configured to provide a positive capacitor voltage between the positive and neutral nodes and to provide a negative capacitor voltage between the negative and neutral nodes. The first device selectively couples the inductor to a first AC input or a positive port of the battery and the second device selectively couples a negative port of the battery to the second input. The inductor is coupled to the first input and is shared between an online mode of the converter and an on-battery mode of the converter. The battery is coupled through the inductor to the first input during the on-battery mode.

Abstract: A front-end converter in an uninterruptible power supply system includes: a boost circuit having first and second inputs, and positive, negative, and neutral output nodes, and being configured to provide a positive capacitor voltage between the positive and neutral nodes and to provide a negative capacitor voltage between the negative and neutral nodes; an inductor coupled to the first input; first AC and neutral AC inputs to receive AC power; a battery; a first device to selectively couple the inductor to the first AC input or a positive port of the battery; and a second device to selectively couple a negative port of the battery to the second input; where the inductor is shared between an online mode of the converter and an on-battery mode of the converter and the battery is coupled through the inductor to the first input during the on-battery mode.