Eliminating harmonics in a multilevel converter using resultant theory

A method is given to determine conditions for which the switching angles in a multilevel converter can be chosen to produce the required fundamental voltage while at the same time cancel out higher order harmonics. A complete analysis is given for a 7- level converter where it is shown that for a range of the modulation index m/sub I/, the switching angles can be chosen to produce the desired fundamental V/sub 1/=m/sub I/(s4V/sub dc///spl pi/) while making the 5/sup th/ and 7/sup th/ harmonics identically zero.