IMA Journal of Applied Mathematics Advance Access originally published online on August 19, 2009
IMA Journal of Applied Mathematics 2009 74(5):782-805; doi:10.1093/imamat/hxp025
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Voltage and current spectra for a single-phase voltage source inverter

School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Email: stephen.cox{at}nottingham.ac.uk
Received on December 10, 2008; Accepted on July 22, 2009
An inverter converts a direct current power supply to an alternating current power supply. To do so, its output is switched at high frequency between the inputs in order to synthesize the desired alternating current output in the low-frequency part of the Fourier spectrum. Here, we calculate analytical expressions for the input and output current and voltage spectra for two inverter designs: so-called single-phase-leg and two-phase-leg inverters. The output voltage and current spectra are well known but are found here by a new, analytically compact means. More significantly, the input current spectra for the two designs are calculated here for the first time. A prior, approximate method for determining the input current spectrum (which assumes an exactly sinusoidal output current) is compared with our exact results.
Keywords: Black's method; Fourier spectrum; power converters; voltage inverter.