ANALYSIS AND MINIMIZATION OF RIPPLE COMPONENTS OF INPUT CURRENT AND VOLTAGE OF PWM INVERTERS

Analysis and minimization of the ripple components of the input curren t and voltage of three-phase voltage-source pulsewidth modulated (PWM) inverters are presented in this paper. The analytical expressions for the rms values of the input current and voltage ripples as a function of the shape of the PWM reference signal are derived. It is found tha t the reference signal which produces a minimum ripple in the input vo ltage varies as a function of the load power factor. It is also found that the rms value of the inverter input current ripple does not depen d on the shape of the reference signal. In respect of the inverter inp ut current and voltage ripples, the addition of harmonics other than t he third into the sinusoidal reference is neither useful nor necessary . Experimental results are included to verify the derived expressions.