Asymmetrical Single Phase Reduced Switch Nine Level Inverter with Trinary Sequence DC Input for PV based Renewable Energy Systems

This paper presents an innovative Asymmetrical Single-Phase Nine Level Inverter (ASRNLI) that stands out among various available configurations. The design achieves a staircase-like voltage pattern with the highest number of levels while utilizing a reduced number of components. Compared to conventional systems, asymmetric multilevel inverters require fewer components yet manage to create a cascade structure with multiple output levels. The ASRNLI configuration consists of two independent DC sources and 10 switches, allowing it to generate any desired level. This setup offers several advantages, including improved output voltage quality attributed to the switches low blocking voltage. It proves particularly valuable in scenarios where asymmetric DC voltage sources are accessible, such as in modern electric vehicles and AC mini-grids powered by renewable energy sources. To generate gate pulses, the ASRNLI employs the level-shifted pulse width modulation approach. Validation of the suggested ASRNLI configuration was carried out through both MATLAB simulations and the construction of a prototype. The output waveform demonstrated a Total Harmonic Distortion (THD) of 13.50% at the highest fundamental voltage of 400V. Throughout this article, the effectiveness of the ASRNLI configuration is supported by findings from simulations and experimental tests, showcasing its potential as a promising solution for practical applications.