A modified seven-level cross-connected PUC boost multilevel inverter with reduced cost factor and device count

Abstract

Abstract The device count (dC) and cost factor (CF) with the boosting feature are the main challenges in the packed u-cell multilevel inverters as the number of levels are increased in the output voltage. In this paper, to mitigate these problems, a new topology of a 7-level modified packed u-cell boost multilevel inverter (PUC-BMLI) is designed to improve the cost factor and device count. Further, it can be used for a wide range of switching frequencies since only one capacitor is required and the voltage across the capacitor is balanced. To generate a 7-level stepped-up voltage across the load, the PUC-BMLI needs only eight power switches and one capacitor. The proposed topology can boost the input voltage by 1.5 times. To generate a 7-level stepped-up voltage across the output multicarrier phase-disposition pulse width modulation (PD-PWM) has been used. To prove the superior performance of the PUC-BMLI, a comparative analysis with existing single DC source boost MLI has been done. The device count (dC) and cost factor (CF) are the lowest compared to the recently proposed topology employing one dc source and producing 7-level across the output. The dC and CF are 10 and 22.33. All the switches are two-quadrant switches, thus reducing the cost of the overall circuit. THD is found to be 4.10% for output current. The feasibility of the 7-level modified topology is evaluated by Matlab/Simulink simulation and verified by an experimental study using the OPAL-RT 4510 real-time platform.