• Dr.J Upendar
• V.Aditya Yadav
• S.Sreenu
• Bogimi Sirisha

This research work focuses on Three phase improved a cascaded multilevel inverter with multi-carrier sinusoidal pulse width modulation using a variable frequency approach and an active filter. MLI came out as a vital converter in industrial drives to regulate speed and to lower THD level for high power medium voltage applications. Due to harmonic content, traditional inverter-fed induction motor drives have poor voltage and current quality, resulting in energy losses. A new topology of cascaded multilevel inverter with fewer switches is introduced to reduce THD and deliver higher power quality supply. It only requires nine semiconductor devices, whereas conventional topology requires twenty for the same 11-level output. The number of switches need for this configuration is {(n-1)/2} +4 for n level voltage output. Harmonic content is decreased using an active LPF filter. With resistance and an asynchronous motor as load, and FFT analysis, eleven level MLI with active LPF filter and seven level MLI with active filter are simulated. With and without a filter, total harmonic distortion of a voltage waveform is investigated.

Multilevel Inverter, Multi-carrier sinusoidal PWM, Active filter

"Three-phase improved cascaded multilevel inverter with multi-carrier sinusoidal pulse width modulation with variable frequency technique for THD reduction", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.8, Issue 12, page no.f187-f194, December-2021, Available :http://www.jetir.org/papers/JETIR2112523.pdf

"Three-phase improved cascaded multilevel inverter with multi-carrier sinusoidal pulse width modulation with variable frequency technique for THD reduction", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.8, Issue 12, page no. ppf187-f194, December-2021, Available at : http://www.jetir.org/papers/JETIR2112523.pdf