Integration of renewable energy sources into power systems requires efficient multilevel inverters, capable of producing high-quality output voltage with low total harmonic distortion (THD). Conventional multilevel inverters often suffer from high component count, high switching stress, low voltage gain, and increased cost, limiting their practical application. This paper introduces a high-gain novel topology for multilevel inverters with reduced number of total components per level count, low voltage stress on power conductive devices, and minimizing a cost function, which depends on the number of components, standing voltage on switches and diodes, output voltage levels, and gain. The designed topology, which can be applied in photovoltaic (PV) systems, utilizes only one direct current (DC) input supply and a modular structure with the ability of capacitor’s voltage self-balancing. The high gain property and low THD of the proposed topology are two advantages that provide sine output waveform, with no need to a high DC input voltage source. Moreover, generalized topology, consisting of cascaded basic units, has been proposed. A comprehensive method has been proposed to determining the values of DC supplies in this configuration, aiming to minimize redundant switching modes and maximize the voltage levels count. The comparison with some other multilevel inverters confirms the desired performance of the basic version given inverter. A prototype has been also implemented and the experimental results have been obtained to verify the advantages of the proposed 25-level topology.

Multilevel inverter  /  Lowering voltage stress  /  High gain  /  Low total harmonic distortion (THD)