Affiliations: [a] Department of Electrical Engineering, Harbin Institute
of Technology, PO Box 350, HIT, Harbin 150001, Heilongjiang Province, P.R.
China. Tel.: +86 451 86412946 616; Fax: +86 451 86412946 611; E-mail:
anquntao@163.com, motor611@sina.com, zhk_mail2002@yahoo.com.cn
Abstract: A novel single power hybrid asymmetrical multilevel converter
(SPHAMC) topology is proposed. By adding an assistant leg to control the
neutral-point voltage independently, the presented converter conquers the
difficulties of controlling the neutral-point voltage and the sub-converter
capacitor voltages in traditional SPHAMCs. The related control strategies are
studied in this paper. In order to ensure the stability of the sub-converter
capacitor voltages, a PI regulator is employed to control the main converter
output voltage. Redundant states selection (RSS) and duty cycle modulation
(DCM) methods are implemented to regulate the sub-converter capacitor voltages
during each output voltage period. The simulation results as well as
experimental ones illustrate the validity and efficiency of the proposed
topology and control strategies.
Keywords: Multilevel converter, hybrid asymmetrical, single power, topology, control strategy
