High-quality power of the packed U-cell 5 inverter using PID and Fuzzy Logic Control

Abstract

This research investigates the performance of five- and seven-cell packed U-Cell (PUC) inverters, highlighting their advantages in reducing harmonic distortion and improving system performance, particularly when used with low-rated filters and fewer components, compared to traditional inverters such as neutral-point clamped, cascaded H-bridge, and flying capacitor inverters. Both inverters employ a sinusoidal PWM method (Pulse Width Modulation technique). The study evaluates the effectiveness of the PUC 7 and PUC 5 inverters, emphasizing their structural differences. The PUC 7 inverter exhibits increased complexity due to the inclusion of numerous sensors and control systems that regulate the capacitor-side voltage, maintaining it at approximately one-third of the input DC voltage to ensure proper voltage balancing. This inverter faces challenges in voltage balancing and requires precise sensor measurements. In contrast, the PUC 5 inverter operates without these issues, utilizing sensorless technology that eliminates the need for voltage balancing, making it a more straightforward and more cost-effective alternative. This study also investigates the improvement of total harmonic distortion (THD) in the PUC 5 inverter through the application of fuzzy logic control and PID controllers. These control strategies aim to reduce THD and improve overall system performance. The effectiveness of the proposed methods is validated through simulations, which demonstrate the advantages of the PUC 5 inverter in terms of simplicity, performance, and reduced harmonic distortion, compared to the more complex PUC 7 inverter. The results provide valuable insights for selecting the optimal inverter configuration in applications where mitigating harmonic distortion is critical.