Abstract: Variable Frequency Drive (VFD) technology is increasingly applied in industrial loads such as pumps. However, VFDs with six-pulse bridge rectifiers act as nonlinear loads, injecting substantial harmonic currents into the grid and degrading power quality. This studyinvestigates harmonic generation and superposition in parallel multi-VFD operations via simulation and designs an effective Active Power Filter (APF) for mitigation. Simulations were conducted under various conditions, Fast Fourier Transform (FFT) analysis quantified grid-side input currents, revealing severe harmonic pollution, with Total Harmonic Distortion (THD) exceeding standards (30%–40%). Results aligned with national harmonic superposition standards and ABB''s DriveSize software, validating the Simulink model''s accuracy. Post-APF compensation, THD reduced to below 5% across scenarios, effectively suppressing harmonics. This research replicates VFD harmonic mechanisms, confirms APF''s superior performance as an active mitigation strategy, and provides simulation-based insights for harmonic assessment and governance in similar engineering projects.