Patent ID: 7619323
Filing Date: 2009-11-17
Classification: H02J

Abstract:
1. An uninterruptible power supply for providing a sinusoidal-wave output AC voltage, comprising: a battery pack; a DC/DC converter unit coupled to the battery pack for converting a DC voltage provided by the battery pack into a full-wave rectified DC voltage; and an inverter coupled to the DC/DC converter unit for converting the full-wave rectified DC voltage into a sinusoidal-wave output AC voltage; wherein the DC/DC converter unit comprises a plurality of DC/DC converters having a plurality of input terminals and output terminals, and wherein the plurality of input terminals of the plurality of DC/DC converters are connected in parallel to the battery pack and the plurality of output terminals of the plurality of DC/DC converters are connected in series to the inverter, and wherein each DC/DC converter is configured to convert the DC voltage provided by the battery pack into an output voltage such that the output voltages of the plurality of DC/DC converters are summed up to form the full-wave rectified DC voltage; wherein the plurality of DC/DC converters include a first DC/DC converter and a second DC/DC converter, wherein one of the first DC/DC converter and the second DC/DC converter is configured to perform switching regulation with a variable duty cycle and the other DC/DC converter is configured to perform switching regulation with a fixed duty cycle, and wherein the first DC/DC converter is an isolated DC/DC converter which has a transformer and the second DC/DC converter is a non-isolated converter.