A New Arduino Compatible Pulse Width Modulation Algorithm for a Five Level Inverter

An algorithm is developed for the generation of pulse width modulated signals using Dual Reference Modulation (DRM) for a five level inverter used in Photovoltaic (PV) based electrical power generation systems. With five level inverters offering a significant edge over the conventional inverters along with an efficient algorithm that is developed in this work, it becomes extremely simple and viable for implementation. This algorithm is made to be compatible with Arduino to facilitate easier implementation while also focusing on reducing the Total Harmonic Distortions (THD) below what conventional five level inverters offer. The developed algorithm to generate PWM signals uses DRM technique that employs one carrier signal and two reference signals. Extensive simulations have been carried out in Simulink. The five level inverter with a reduced number of switches is fabricated and tested on an experimental setup. Experiments have been carried out on the developed inverter and its performance is analyzed considering voltage, current and THD on the output for different modulation indices and switching frequencies. For a switching frequency of 2 kHz and a modulation index of 1, THD obtained with the five level inverter is around <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{2 0 \%}$</tex>. It is inferred that the implemented PWM algorithm on the inverter produced five levels on the output with an easier implementation algorithm, while employing a reduced number of switches.