Single-phase uninterruptible power system topology concepts: Application to an universal active filter

This paper discusses the possible control techniques for UPS and relates these control techniques to the different single-phase UPS topologies found in literature. These possibilities have been mentioned in separate but they have never been put together. Also, techniques for using a low battery voltage are discussed. Finally, a combination of different possibilities of UPS structures and one of the types of operation control is applied to an universal active filter with the function of UPS, with low battery voltage and without any transformer, thus reducing cost and weight. Simulated and experimental results verify the proposed topology.