A single source five-level switched-capacitor based multilevel inverter with reduced device count

Abstract

Nowadays, multilevel inverters (MLIs) are widely used for integration with renewable energy (RE) resources and in industrial applications. Among different RE sources, photovoltaic (PV) energy is generally used for the generation of power. For accumulating more power from PV systems, the Fuzzy Logic Controller (FLC) technique is used to trace the maximum power (MPP). The FLC computes the reference PV voltage guarantee to ensure optimal power transmission between the PV system and the MLI's connected load. In this paper, a novel 5L (five-level) PV-based switched-capacitor MLI topology (PV-SC-MLI) has been projected with the target of reducing the number of switches and boosting the input voltage without any bulky transformer. A selected harmonic elimination pulse width modulation technique (SHEPWM) based technique is used to remove the harmonic for 5L-PV-SC-MLI. The projected technique is appropriate for all levels of MLIs, including non-equal and equal DC sources. The SHEPWM technique is used to solve the non-linear transcendental equations and obtain the optimal values of switching angles. The obtained switching value is used to reduce the total harmonic distortion (THD) of 5L-PV-SC-MLI. The THD at the output voltage of proposed inverter has been obtained value is 8.72% without filter and with filter 4.20%, which lies within the limits of IEEE 519 standards.

Keywords

• Photovoltaic (PV) energy
• Switched-capacitor MLI
• Fuzzy logic controller (FLC)
• SHEPWM technique
• THD