Performance Evaluation of Filter Design Techniques for Harmonic Control in Three-level Inverter Systems

This study investigates harmonic reduction in three-level inverters, focusing on the performance of single-tuned and double-tuned filters. Inverters, essential in microgrids for converting DC to AC power, often face the challenge of harmonic distortion, which can degrade power quality. The research models a three-level inverter using MATLAB, with design parameters for both filter types derived through mathematical equations. A comparative analysis was conducted to evaluate the effectiveness of single-tuned and double-tuned filters in minimizing total harmonic distortion (THD) at the inverter's output. Results show that both filters reduced THD to levels compliant with International Electrotechnical Commission (IEC) standards, but the double-tuned filter outperformed the single-tuned filter, achieving a lower THD. This demonstrates the superior capability of the double-tuned filter in enhancing the power quality of the inverter system. The study provides valuable insights into filter selection for inverters, offering a solution to the challenge of designing effective filters for harmonic reduction, with a particular emphasis on the advantages of using double-tuned filters in three-level inverter systems.