A PWM schenle for a 3-level inverter cascading two 2-level Inverters

Abstract

This paper shows that 3-level inversion can be achieved by connecting two 2-level inventers in cascade. Two isolated power supplies with DC link voltages are required for the proposed circuit topology. The voltages constitute half of that of a conventional 3-level invener topology. Neutral point fluctuation is absent in the proposed scheme when compared to conventional neutral point clamped 3-level inventer. A sine-triangle-based PWM scheme is presenred for the proposed topology.