Cascaded Multi-Level Inverter with Asymmetrical Voltage Sources Using Multicarrier PWM Strategies

Advanced multilevel inverters are pivotal in modern power electronics for achieving low-distortion waveforms and minimizing voltage stress on switching elements.This study introduces a cascaded H-bridge inverter design that employs asymmetrical DC sources configured in a trinary sequence, successfully delivering higher output voltage levels with fewer components than conventional topologies.A multi-carrier PWM approach is implemented with three modulation schemes Phase Disposition (PD), Phase Opposition Disposition (POD), and Alternate Phase Opposition Disposition (APOD) which are systematically evaluated through both MATLAB/Simulink simulations and hardware tests using a dSPACE DS1103 controller.Key performance measures, including total harmonic distortion, RMS voltage, crest factor, and form factor, are rigorously assessed.Experimental findings confirm that the APOD strategy offers superior harmonic suppression, while the trapezoidal MCPWM method enhances waveform quality and alleviates switch voltage stress.The results validate the proposed topology as an efficient, scalable solution for advanced power conversion applications.