A Novel Three-Phase 13-Level Cascaded Hybrid-Module Based Multilevel Inverter With Level-Shifted Modified-PWM Algorithm

This article proposes a novel structure for a three-phase multilevel inverter that utilises switched-capacitors (SCs). The proposed structure has the ability to enhance the input voltage and generate 13 voltage levels at the output by employing three distinct DC voltage sources. The proposed structure additionally features self-charging capability and can automatically regulate the capacitor's voltage, without the need for any external circuit/sensor. Level-shifted carriers modified-PWM (LSCs-MPWM) algorithm regulates the charging and discharging of the capacitors, resulting in self-balancing capacitors' voltage with suppressed voltage ripples across the capacitors. The proposed structure has undergone a quantitative comparison with similar structures in order to ensure its advantages in the aspects of reduced components count, boosted output voltage, low THD, higher efficiency, lower cost function per level, less voltage stress, and small-sized SCs. The proposed topology is simulated in MATLAB/SIMULINK environment and a laboratory prototype inverter is developed to verify its feasibility to operate at steady-state and transient conditions.