A novel self-boosting 5-level inverter for grid-connected photovoltaic system

Abstract

Renewable energy systems are presently recognized as the primary alternative power source due to increased electricity demand and the depletion of fossil resources. The photovoltaic (PV) system is a rapidly growing renewable energy system. Inverters are used to integrate PV systems to the utility grid. Multilevel inverters are the most popular option for PV application due to reduced total harmonic distortion (THD), switching stress, and electromagnetic interference. This work presents a 5-Level grid-connected inverter while minimizing the cost. The proposed inverter uses six unidirectional switches and one diode with a single switched capacitor. Furthermore, it removes the requirement of multiple isolated DC sources. A simple modulation technique generates a suitable switching pulse for the inverter. Additionally, the comparison of the proposed inverter with the other topologies existing in the literature shows that it has reduced power devices, total standing voltage (TSV), and cost function. The PV connected grid system is investigated with specified controlling and implemented in MATLAB/Simulink and validated through hardware-in-the-loop (HIL) real-time simulation in OPAL-RT. In addition, the laboratory setup of the proposed structure is built and tested to verify its effectiveness.