Vector classification and voltage control in PWM three-level inverters

It has been recognized that the deployment of multi-level converters can be efficient from the view point of converter power rating and its output voltage quality. On the contrary, increasing the number of converter levels results in control and power circuit complexity. On the other hand, benefits of neutral clamped multilevel converters (NPC) highly rely on the dc side capacitor voltage balancing. This paper provides experimental evidences that the use of recently proposed vector classification scheme along with a new voltage balancing technique can considerably solve the multilevel problems. The proposed scheme is easy to implement, needs less hardware and software, provides accurate switching instances and balances the neutral point voltage properly.