Common-Mode Reduction for ANPC With Enhanced Harmonic Profile Using Interleaved Sawtooth Carrier Phase-Disposition PWM

• Published in: IEEE transactions on industrial electronics (1982) 2016-12, Vol.63 (12), p.7887-7897
• Main Authors: Ziyou Lim, Maswood, Ali I., Ooi, Gabriel Heo Peng
• Format: Article
• Language: English
• Subjects: Active neutral-point-clamped converter (ANPC); Capacitors; common-mode voltage (CMV) reduction technique; Feasibility studies; Fourier analysis; Harmonic analysis; Inverters; Multilevel; Phase modulation; Pulse duration modulation; Pulse width modulation; Switches
• ISSN: 0278-0046; 1557-9948
• DOI: 10.1109/TIE.2016.2592459

Multilevel active neutral-point-clamped (ANPC) converter is popularly known for its higher medium voltage drives up to 6.9 kV. However, common-mode voltages (CMV) are generated when using the well-established carrier-based pulse width modulation (PWM) modulation technique. As a result, CMV will become the major cause of the premature bearing failures and the conducted electromagnetic interferences. In this paper, a reduced CMV strategy is proposed for the ANPC which employs an alternatively new hybrid carrier-based modulation named as interleaved sawtooth carrier phase-disposition PWM (ISC-PD-PWM). By doing so, enhanced harmonic profile is achieved as compared to the typically used classical phase-shifted carrier PWM (PSC-PWM). Therefore, a comparative evaluation of the seven-level (7L) ANPC performance using the proposed reduced CMV approach is made between the novel hybrid ISC-PD-PWM and the conventional PSC-PWM in terms of harmonic analysis. The experimental results have proven the feasibility of the proposed concepts with the CMV effectively reduced. Such perceived merits make ANPC be more attractive for its motor drives.