New modulation methods for force-commutated direct frequency changers

Single-stage switching transfer functions of force-commutated frequency changes are generalized for an arbitrary number of input/output phases. Then, practical modulation methods and their mathematical analysis for generalized switching transfer functions are presented. The proposed modulation techniques are mathematically justified and were implemented using microprocessors. The quality of the generated waveforms is analyzed to develop proper modulation methods and improve the quality of the waveforms. Harmonic analysis methods for the force commutated direct frequency changers are also described.<>