INTRODUCING PULSE ANGLE MODULATION FOR INVERTERS

This paper introduces three types of pulse angle modulations found to be suitable for application to variable voltage variable frequency inv erters, namely: (i) pulse position modulation, (ii) pulse frequency mo dulation and (iii) pulse repetition period modulation. Their harmonic analyses show very low relative values of low order harmonics, near th e reference frequency. Modifications to the second and third types are introduced to further reduce the relative values of low order harmoni cs. Variation of the magnitude of the reference frequency component is investigated by varying either the modulation factor or the duty cycl e. It was proven and verified that varying the duty cycle does not aff ect the harmonic spectrum near the reference frequency.