nine level modular multilevel converter with modified level shift modulation technique for reduced switching frequency

This study introduces a new approach to pulse width modulation (pwm) known as the adapted dc level shift pwm technique (dc-pwm), which is applied to a nine level modular multilevel converter. this modulation technique involves interleaving the modulated waveform with a direct current (dc) level, while ensuring that quarter wave symmetry is preserved. by implementing an adjusted level shift 1/4 dc-phase disposition (pd) pwm and 2/4 dc pdpwm modulation technique, the switching frequency of the nine level modular multilevel converter (mmc) has been successfully reduced. the technique’s effectiveness has been confirmed through validation using simulink/matlab and an experimental setup. the simulation results show a notable decrease in the frequency of action switching. when it comes to harmonic performance for phase voltage, line voltage, and capacitor voltage, the type-3 1/4 dc-pdpwm technique generally outperforms the 2/4 dc-pdpwm technique. the 2/4 dc-pdpwm type-2 demonstrates impressive performance, particularly in terms of phase current and capacitor voltage %thd. the selection of these techniques will be determined by the specific performance needs and the trade-offs in complexity and harmonic suppression that are deemed acceptable for the intended use.