Abstract: An increase in the research of medium-voltage AFD (adjustable frequency drive) system for the save of electrical energy has been seen during recent years. There are various converters configuration for medium-voltage and control methods abroad, but the detail control methods are rarely seen on publications. This paper has described two novel control strategies for voltage-source (VS) AFD systems of medium-voltage, and analyzed output waveforms, RCMV (rectifier-common-mode voltage), ICMV (inverter-common-mode voltage) and output waveform spectrums as well. For every control strategy a good few conclusions have been attained through simulation analysis.