Novel carrier PWM scheme to control neutral point voltage fluctuations in three-level voltage source inverter

This paper presents a simple PWM technique to control neutral point voltage of the multi-level inverter. The multi-level power conversion systems have been receiving increasing attention, especially for high power applications. The proposed method employs a modified version of multi-level sinusoidal pulse width modulation (SPWM) scheme. This method avoids the requirement of high capacity DC link capacitors, which are employed in most of the present three-level inverter industrial applications. The new PWM scheme is less complex than most of the other available neutral point clamping control methods.