DESIGN AND ANALYSIS OF AN ADAPTIVE HYSTERESIS BAND DELTA MODULATOR FOR VSI

Abstract

This paper presents the design, analysis and implementation of a delta modulator with adaptive hysteresis band for voltage source inverters in order to enable PWM switching frequency to be fairly constant. With this inherent advantage, the contaminated frequency modulation is reduced;thus, eliminating subharmonics. This characteristic will be useful for reducing load currelIt ripple due to the variation of switching frequency over the fundamental period. This paper fully describes circuit parameters and interprets mathematical expressions for designing the control circuit. Additionally,the performance of proposed delta modulators is illustrated, both by simulated and experimental results.