Simplified carrier based space vector for n-level converter

Abstract

Sine-triangle Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM) techniques are widely used in the control of inverters. With the introduction of multi-level inverters, the use of carrier based SVPWM has gained popularity as this method is capable of dealing with the complexity brought about by the large number of voltage vectors. This paper presents the concept of carrier based SVPWM in a straight forward manner and shows how it can be used for the general n-level inverter. A mathematical description is given for better understanding of the carrier based SVPWM technique for two-level inverters. The requirements are then established for the carrier based PWM techniques and finally the concept is visualized with the centered space vector PWM technique for any level inverter. Simulations using centered SVPWM are used to visualize and demonstrate the method.