Application of Fourier Series Expansion to Electrical Power Conversion

Abstract

Many power electronic applications demand generation of voltage of a rather good sinusoidal waveform. In particular, dc-to-ac voltage conversion could be done by multilevel inverters (MLI). A number of various inverter topologies have been suggested so far: diode-clamped (DC) MLI, capacitor-clamped (CC) MLI, cascaded H-bridge (CHB) MLI, and others. Fourier series expansions have been used to investigate and to form a basis of different topologies comparison, to discover their advantages and disadvantages, and to determine their control. In this chapter, we discuss modulation strategies of DCMLI and CHBMLI, solve their harmonics spectra analytically, and compare them using harmonic distortion indices.