Modulation strategies of three phase PWM inverters: Analysis and comparative study

This paper presents a systematic study and analysis of the various modulation strategies for three phase pulse width modulated (PWM) inverters. Analytical expressions are derived to obtain harmonic components of output voltages for duty ratio, sine, triangular and step modulation. A comparative study of the merits and demerits of the various modulation techniques is presented. The effects of ratios of carrier and reference frequencies, and the instant of synchronisation are investigated. Use of a particular modulation strategy for a particular application is discussed.