A performance assessment of nine-stage ternary DC source mli through various PWM topologies

Abstract

ABSTRACT In modern days, MLIs comprise a lot of concentrations in academia and industry. As they are altering interest in a feasible technology in supporting frequent applications of renewable energy conversion systems and drives, these huge power and medium/higher voltage applications and MLIs are extensively used as one of the sophisticated powers converter topography. The MLIs are divided into two types such as asymmetric and symmetric. MLIs of the asymmetric kind have more amount of output AC voltage stage with fewer DC input source voltage and switching components. In this research paper, asymmetric single-phase cascade full-bridge MLI is developed with carrier-based unipolar PWM techniques. This MLI can generate nine-stage of output AC voltage through eight switches and two input DC sources. It is tested through a variety of multicarrier unipolar PWM control combinations. The Phase Disposition (PD), Alternating Phase Opposition Disposition (APOD), Carrier Overlapping (COP) and Variable Frequency (VF) are all PWM control which included in support of preference of single-phase nine-stage ternary cascade multilevel inverters. With various modulation indices (ma), the harmonic substance of output AC voltage for each approach is observed and tabulated. The proposed design for generating nine-stage output AC voltage is demonstrated using MATLAB-SIMULINK and confirmed using a laboratory-based prototype model. The results show that the unipolar Alternating Phase Opposition Disposition PWM technique that provides a high-quality output voltage with less harmonic distortion. Besides, the performance of Carrier Overlapping PWM techniques is greater since it produces a superior fundamental RMS output AC voltage.