Development of Single Phase UPS having AC Chopper and Active Filter Ability

This paper describes about development of single phase uninterruptible power supply (UPS) having AC chopper and active filter ability. The proposed UPS consists of a single phase full bridge type active filter and the source and load side AC choppers using bidirectional IGBT switches. It realizes long life and maintenance free of the main circuit because it has no use of the bulky electrolytic capacitor. The proposed UPS has active filter ability between the source and load side choppers, which realizes unity input power factor operation. The AC chopper regulates the output voltage sinusoidaly. The fundamental source power supply to the load in direct without switching of the every AC choppers under the normal power condition, which achieves high efficient system and high system reliability. The simulation results point out that the proposed UPS has the desired input and output characteristics such as 99% power factor and under 3% voltage regulation.