Title: A novel invariable carrier frequency multi-level inverter PWM for balancing switching transitions and better distribution of harmonic power

Authors: S. Jeevananthan; S. Paramasivam; S. Thamizharasan

Addresses: Department of Electrical and Electronics Engineering, Pondicherry Engineering College, Pondicherry 605 014, India. ' ESAB Engineering Services Limited, Chennai 600 058, India. ' Department of Electrical and Electronics Engineering, Surya School of Engineering and Technology, Surya Group Institutions, Villupuram District, Tamil Nadu 605 652, India

Abstract: The number of switching per modulation cycle at each level in a multi-level inverter depends on the carrier frequency and the duration that the reference waveform dwells within the level. The variable carrier frequency band (VFCB) approach creates as many clusters as the number of carrier frequencies and consequent deterioration of the harmonic spectrum. Therefore, a new pulse width modulation (PWM) strategy, with the view to ensure that the power devices at all the levels are switched equal number of times, is proposed in this paper. It is designed such that the frequency of the carrier waves is allowed to remain constant for the chosen application while maintaining the number of switching for all devices is same. The MATLAB-based simulation response and its experimental validation are included to highlight the fact that there is a significant enhancement in harmonic power distribution besides contributing to reduce the switching losses and improve the efficiency.

Keywords: pulse width modulation; PWM; variable carrier frequency band; VFCB; varying amplitude carrier band; VACB; multi-level inverters; MLI; harmonic power.

DOI: 10.1504/IJPELEC.2012.046601

International Journal of Power Electronics, 2012 Vol.4 No.3, pp.290 - 301

Accepted: 28 Feb 2011
Published online: 23 Aug 2014 *

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