Simulation Design of Three-Level Hysteresis Active Power Filter (APF)

This study presents a simulation design for a three-level hysteresis active power filter (APF), incorporating harmonic detection, current tracking mechanisms, and Z-domain analysis. The filter plays a critical role in power systems by effectively reducing harmonic interference and improving power quality. During the simulation process, we conduct detailed analysis of harmonic detection algorithms (typically implemented using instantaneous power theory or FFT-based methods) and current tracking components (utilizing hysteresis comparator control with three-level output states). The implementation involves generating reference currents through harmonic extraction and employing switching logic to maintain current errors within hysteresis bands. Additionally, Z-domain analysis methods are applied to investigate the filter's frequency response characteristics, providing deeper insights into its operational principles. Through these simulation designs, we gain comprehensive understanding of the features and advantages of three-level hysteresis APFs, offering valuable references and guidance for practical applications in power quality improvement.