Delta Modulated Rectifier-Inverter for Uninterruptible Power Supplies

Various PWM technique have been proposed so far for uniterruptible power supply (UPS) systems to obtain near distortionless output voltage as well as maintaining good input power factor and input current waveshape. The results of using delta modulation technique (DM) for modulating the gating signals of the rectifier and the inverter of a UPS system are presented in this paper. The DM technique of generating gating signals for converters provide the control of the rectifier voltage and also control of the dc to ac conversion at the inverter side. Analysis of rectifier and inverter performance for the DM pulse width modulation (PWM) operation of rectifier inverter is described and the results are verified experimentally.