CASCADED MULTILEVEL PV INVERTER WITH IMPROVED HARMONIC PERFORMANCE DURING POWER IMBALANCE BETWEEN CELLS
Abstract
The paper describes a presented solution to address the issue of changing battery duty cycles affecting voltage output in a cascaded multilevel converter for photovoltaic (PV) applications. The presented solution involves using H6 bridge cells instead of H bridge cells to ensure a consistent duty cycle across all cells and maintain high-quality voltage output and waveforms of current. The MAXIMUM POWER OUTPUT determines the duty cycle of the battery in the cascaded multilevel converter, which takes into account various radiation conditions beyond fractional shading of solar panels. However, changing the battery duty cycle affects the voltage output which is proportional to current distortion. Therefore, it is not a desirable option. To address this issue, the presented idea suggests using a layered idea with H6 bridge cells. This solution ensures that the duty cycle across all cells remains consistent, irrespective of weather conditions. As a result, the voltage output and waveforms of current remain of high quality. To assess the efficacy of the presented solution, a comprehensive simulation circuit model was constructed. The simulation results indicate that the presented idea yields superior voltage output and current characteristics compared to the H-bridge cascade idea. Additionally, the presented idea provides improved harmonic performance in line with European efficiencies, resulting in a 2.64% increase over other topologies. The presented idea has the potential to enhance the performance of cascaded multilevel converters in PV applications, as it addresses the issue of changing battery duty cycles and ensures high-quality voltage output and waveforms of current. The solution's effectiveness has been evaluated using a comprehensive simulation model, making it a promising solution for real-world applications
Keywords
Optimized Power output, Cascaded converter, H-bridge, Fractional shading, Power quality, Multilevel converters