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

This simulation design focuses on a three-level active power filter (APF) incorporating an LCL filter, comprising harmonic detection, current tracking loop, SPWM modulation, and discrete domain analysis. These components work collectively to achieve effective harmonic filtering and precise tracking control in power systems. The implementation begins with harmonic detection algorithms (typically using FFT or instantaneous power theory) to identify harmonic components in the power system. Subsequently, the current tracking loop employs proportional-integral (PI) controllers or predictive control algorithms to accurately track current variations and achieve precise harmonic compensation. The design then utilizes SPWM modulation techniques to convert control signals into PWM signals through carrier comparison and modulation index calculation, enabling effective harmonic elimination in the power system. Finally, discrete domain analysis involves z-domain transformations and stability criteria evaluation (such as Nyquist or Bode analysis) to verify the filter's effectiveness and stability. Through this comprehensive simulation design approach, we can better understand and optimize the application of three-level active power filters in power systems, with potential code implementations involving MATLAB/Simulink modules for harmonic analysis, control system toolboxes for current tracking, and Simscape Electrical for power electronics modeling.