A Fibonacci Series based Nearest Level Modulation Scheme for Multilevel Inverters

Modulation scheme in multilevel inverters (MLI) carries an important role in efficient power conversion from DC to AC power. They are superior in performance to the conventional two and three-level inverters. Recently, the Low Switching Frequency modulation schemes have gained a good amount of significance over High Switching Frequency modulation schemes because of their various advantages such as reduced switching losses, lower device cooling requirements, higher converter efficiency and so on. A Fibonacci series based NLM scheme named as F-NLM is presented in this paper where several iterations were carried out to arrive at an optimal set of switching angles following the Fibonacci number series. An asymmetrical Cascaded H-Bridge Inverter (CHBI) is taken up for the study to generate a nine-level MLI output. We carried simulations out in MATLAB environment, and we found the proposed modulation scheme to reduce the voltage THD and improve the power quality.