Abstract: An uninterruptible power supply (UPS) system includes first and second busses, a first switching circuit configured to selectively couple an AC source to the first and second busses and a second switching circuit configured to selectively couple the first and second busses to a load. The system also includes a storage capacitor and a third switching circuit configured to couple the storage capacitor between the first and second busses. The system further includes a control circuit configured to control the first, second and third switching circuits to generate an AC voltage at the load.

Abstract: An uninterruptible power supply (UPS) system includes first and second busses, a first switching circuit configured to selectively couple an AC source to the first and second busses and a second switching circuit configured to selectively couple the first and second busses to a load. The system also includes a storage capacitor and a third switching circuit configured to couple the storage capacitor between the first and second busses. The system further includes a control circuit configured to control the first, second and third switching circuits to generate an AC voltage at the load.

Abstract: A power supply system includes an AC input configured to be coupled to an AC source, an AC output configured to be coupled to a load, a UPS having an input coupled to the AC input and an output coupled to the AC output and a bypass circuit coupled between the AC input and the AC output and configured to open and close a bypass path therebetween. The system further includes a controller configured to control the UPS and the bypass circuit such that the UPS operates as an online UPS for a first input voltage magnitude condition at the AC input and as a standby UPS for a second input voltage magnitude condition at the AC input. A multi-mode converter may be coupled to a DC link of the UPS and configured to be selectively coupled to a battery and the AC input to respectively support battery conversion and current control at the AC input in respective first and second modes of operation of the UPS.