Title :
An improved cascaded H-bridge multilevel inverter controlled by an unbalanced voltage level sigma-delta modulator
Author :
Liao, Jingsheng ; Ferdowsi, Mehdi
Author_Institution :
Missouri Univ. of Sci. & Technol., Rolla, MO
Abstract :
Multilevel inverters have been proven to be viable solutions for high-power automotive motor drive applications due to their high volt-ampere ratings. Cascaded H-bridge inverters are a promising breed of multilevel inverters which generally require several independent dc sources. Replacement of all but one of the dc sources with capacitors in cascaded H-bridge multilevel inverters, which leads to single-dc-source per-phase cascaded inverters, has recently gained popularity. However, very few efforts have been made to address the challenging problem of voltage regulation in the replacing capacitors. In this paper, applicability of a real-time voltage control technique named unbalanced voltage level sigma-delta modulation technique to provide voltage regulation across the replacing capacitors is examined. In addition, a new voltage ratio for the H-bridge cells is introduced, which simplifies the control tasks. Analytical and simulation results prove the effectiveness of the proposed scheme.
Keywords :
bridge circuits; delta-sigma modulation; invertors; power capacitors; voltage control; cascaded H-bridge multilevel inverter; high-power automotive motor drive; real-time voltage control technique; single-dc-source per-phase cascaded inverters; unbalanced voltage level sigma-delta modulator; voltage regulation; Automotive engineering; Capacitors; Delta modulation; Delta-sigma modulation; Inverters; Motor drives; Propulsion; Pulse modulation; Vehicle driving; Voltage control; Delta-Sigma modulator; H-bridge multi-level inverter; spectrum analysis; voltage regulation;
Conference_Titel :
Vehicle Power and Propulsion Conference, 2008. VPPC '08. IEEE
Conference_Location :
Harbin
Print_ISBN :
978-1-4244-1848-0
Electronic_ISBN :
978-1-4244-1849-7
DOI :
10.1109/VPPC.2008.4677614