Single Phase 17-Level Asymmetric CHB Multilevel Inverter Using Fundamental Switching Frequency Modulation

In this paper, a 17-level asymmetric Cascaded H-Bridge (CHB) converter with integrating a Level Doubling Circuit (LDC) is presented. A fundamental switching frequency modulation technique is adapted for the generation of required gate pulse to the proposed topology. The suggested architecture necessitates the use of two asymmetric DC sources with a 1:3 magnitude ratio, ten switches, and a self-balanced capacitor. By cascading the H Bridges, the suggested architecture can create a greater number of voltage levels. The proposed Asymmetric CHB inverter generates N levels with the help of
$log_{3}(\frac{\mathrm{N}+1}{2})$
DC sources,
$2+4 log_{3}(\frac{\mathrm{N}+1}{2})$
switches, and a capacitor. In comparison to the existing topologies presented in literature, the proposed Asymmetric CHB requires fewer switches and DC sources for an N number of voltage levels. The proposed topology is simulated in the MATLAB/SIMULINK. A Level Shift - PWM (LS-PWM) method is implemented by considering the carrier frequency is equal to 50Hz. Further, the simulation results are verified experimentally using dSPACE 1104 by use of a prototype model made in a laboratory. In the output voltage waveform, the Total Hormonic Distortion (THD) is less than 5%.