A novel voltage-controlled delta-modulated UPS inverter control scheme

This paper presents a novel voltage-controlled delta-modulated inverter control scheme for UPS applications. Comprehensive analysis for system performances on the basis of theory, computer simulation, and experiment are presented. The proposed voltage-controlled delta-modulated inverter control scheme is able to make a voltage source inverter (VSI) act as an ac voltage source and thereby, the amplitude perturbation caused by load and DC rail voltage variations, the waveform distortion caused by load non-linearity, of the UPS output voltage are all suppressed. The principles of the proposed system configuration and operation are introduced. The effects of the system parameters variation on the system performances are analyzed with discrete Fourier transform (DFT) and MATLAB simulation, and the resultant normalized curves can be used as engineering design guideline. Experiment results validate both the theoretical analysis and the simulation results.