• N JAYA NAGA LAKSHMI
• k.kavitha

When asymmetrical inverter is operated in PWM mode it gives high value of total harmonic distortion (THD) which is mainly due to unequal pulses in the each stage of multilevel output. To avoid this hybrid asymmetrical inverter is proposed in this paper with asymmetrical and symmetrical parts. The main objective is to get the same THD value in asymmetrical inverter as same level symmetrical inverter when both are operated in PWM mode. Hybrid symmetrical inverter is proposed with modified PWM technique and it can be used in symmetric part of the hybrid asymmetric inverter. Further in this paper a novel operation called as modified PWM operation is proposed for cascaded multilevel inverters in order to decrease high frequency switches in these inverters. This proposed inverter uses few levels at high frequency and remaining at low frequency. Henceforth this proposed PWM operation which uses more number of low frequency switches gives the same output as that obtained without using this modified PWM operation. This decreases the cost of the inverter and increases the reliability of the inverter.

Cascaded multilevel inverter, Hybrid asymmetrical inverter, Hybrid symmetrical inverter, Pulse width modulation, Total harmonic distortion

"Hybrid Symmetric and Asymmetric Cascaded Multilevel Inverters with Modified PWM Operation", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.4, Issue 9, page no.53-63, September-2017, Available :http://www.jetir.org/papers/JETIR1709012.pdf

"Hybrid Symmetric and Asymmetric Cascaded Multilevel Inverters with Modified PWM Operation", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.4, Issue 9, page no. pp53-63, September-2017, Available at : http://www.jetir.org/papers/JETIR1709012.pdf