Title: Solar PV-fed cascaded multilevel inverters employing zeta converter

Authors: Aquib Mehdi Naqvi; Pushkar Tripathi; S.P. Singh

Addresses: Electrical Engineering Department, Institute of Engineering and Technology, Lucknow, India ' Electrical Engineering Department, Institute of Engineering and Technology, Lucknow, India ' Electrical Engineering Department, Rajkiye Engineering College, Ambedkaragar, India

Abstract: The photovoltaic cell produces DC power, while residential, industrial loads and most modern equipment typically require AC power. Thus, there is a need for power converters that can efficiently convert DC to AC. Although two-level inverters are commonly used for this purpose, they suffer from higher total harmonic distortion (THD) and switching stresses. Multilevel inverter (MLI) technology emerges as an effective solution for high-power medium-voltage energy control. This paper examines cascaded multilevel inverters (CMLIs) of varying levels and multiple-carrier sinusoidal switching techniques, conducting a comparative analysis to identify the most suitable switching technique for implementation in solar stand-alone MLIs. Additionally, the study adjusts the duty ratio of the Zeta converter to optimise power extraction from the solar PV system. The primary focus is on the application of CMLIs in stand-alone solar photovoltaic systems, with the study conducted in the Simulink/MATLAB environment.

Keywords: inverter; multilevel inverter; MLI; cascaded multilevel; total harmonic distortion; THD; SPWM; Simulink; solar; photovoltaic; maximum power point tracking; MPPT; perturb and observe; P&O; zeta converter; multiple-carrier SPWM.

DOI: 10.1504/IJPEC.2025.142879

International Journal of Power and Energy Conversion, 2025 Vol.16 No.1, pp.13 - 37

Received: 15 Feb 2024
Accepted: 18 Apr 2024
Published online: 30 Nov 2024 *