An Asymmetric Source Configuration of Single-Phase CHB-MLI Topology with a Generalized Reduced-Carrier Modulation Technique

In this paper, a generalized reduced-carrier modulation technique is proposed for an asymmetric source configuration of single-phase CHB-MLI topology. To achieve higher level output with fewer modules and isolated DC sources, an asymmetric source configuration is reported in the literature. Basically, trinary (1:3:9) and quasi-linear (1:2:6) source configurations of CHB-topology may offer 27 and 19-levels of output respectively. To achieve a specified level output, level shifted PWM techniques require many numbers of high switching frequency carrier signals and states to decoder arrangements. However, the proposed control technique with reduced carrier modulation does not require states to decoder and thus lowering control complexity. This technique provides low Total Harmonic Distortion (THD) and filtering requirements at the inverter output. The PLECS platform is used to test the functionality of the proposed control scheme.