A Theoretical Analysis of the Harmonic Content of PWM Waveforms for Multiple-Frequency Modulators

• Published in: IEEE transactions on power electronics Vol. 25; no. 1; pp. 131 - 141
• Main Authors: Odavic, M., Sumner, M., Zanchetta, P., Clare, J.C.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-01-2010; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active filters; Active power filter; Applied sciences; Baseband; Capacitors. Resistors. Filters; Circuit properties; Circuits; Convertors; Electric currents; Electric potential; Electric, optical and optoelectronic circuits; Electrical engineering. Electrical power engineering; Electrical machines; Electrical power engineering; Electronic circuits; Electronics; Exact sciences and technology; Fourier analysis; Fourier transforms; Frequency; Frequency filters; Harmonic analysis; Harmonics; Mathematical analysis; Mathematical models; Modulation; Power conversion; Power harmonic filters; Power networks and lines; Pulse duration modulation; Pulse width modulation; Pulse width modulation converters; pulsewidth modulation (PWM); Signal analysis; Simulation; Theory. Simulation; Various equipment and components; Voltage; voltage-source converter (VSC); Waveforms; Harmonic; pulsewidth modulation (PWM); Frequency modulation; Fast Fourier transformation; Harmonic analysis; Base band; Power electronics; Fourier series; Harmonic balance; Voltage source converter; Power filters; Active power filter; Output voltage; Analytical method; voltage-source converter (VSC); Series expansion; Active filter; High frequency; Pulse duration modulation; Multiple frequency; Analytical solution; Comparative study
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2009.2026751

This paper theoretically identifies the harmonic components of a carrier-based pulsewidth-modulated (PWM) voltage-source converter (VSC) output voltage when the modulating wave includes fundamental and baseband harmonic components. This occurs, for example, when a VSC is used as an active power filter. The general analytical solution provided can be applied with a minimum additional mathematical effort to any harmonic combination in the modulation signal. The analysis undertaken in this paper determines how the fundamental and low-order harmonics (in the modulation signal) interact with the carrier to produce the low (and high) order frequencies in the PWM VSC output voltage. The analysis is based on a double Fourier series expansion in two variables. This approach to harmonic identification is evaluated by a comparison with a fast Fourier transform analysis of simulated PWM waveforms.