Multilevel Inverters

In recent years, great progress has been made in high-power industrial applications employing multilevel inverters (MLIs). In high-power environment, low-switching frequency is of prime interest to enhance converter efficiency, which is responded by selective harmonic elimination (SHE) techniques. However, implementation of SHE technique is restricted due to the computational complexities involved in Fourier transcendental SHE equations. The major contribution of this book is four midpoint-based SHE-pulse-amplitude modulation (SHE-PAM) techniques. SHE-PAM techniques calculate switching angles and synthesize reference voltage for dc voltage sources. The proposed techniques work on linear equation-based composite midpoint rule (Gauss formula) of numerical integration. This eliminates massive Fourier computational burden and enables online implementation of the proposed techniques with a great ease for the inverter with a large number of levels. The concept of midpoint is further extended for SHE-pulse-width modulation (SHE-PWM) techniques, working with constant dc-link voltage. Novel reduced device count (RDC) MLI topologies and SHE technique-based STATCOM are presented in the book.