Efficient 81-level sinusoidal and modified sinusoidal multi-stepped inverter

Multilevel inverters with a considerable number of steps (more than 50 levels) can produce high power quality waveforms. Traditionally multilevel inverters employ pulse width modulation (PWM) methods to control the output voltage and total harmonic distortion (THD). This results in high switching losses and hence inefficient implementation. The proposed work addresses the switching losses issue by introducing two new multistep non pulse width modulation algorithms - sinusoidal multistep non PWM algorithm with minimum switching transition and modified sinusoidal multistep non PWM algorithm with minimum switching transition. THD of the proposed methods are well below 5% which is verified using simulation results.