Adaptive Dual Control Mode Switching Strategy for Three-Level Neutral Point Clamped Converter

To address stability challenges caused by weak inertia and wide impedance variations in high-renewablepenetration power systems, along with neutral point potential imbalance in three-level neutral point clamped (3L-NPC) converter, this paper proposes an adaptive grid-following/gridforming (GFL/GFM) switching control strategy. Real-time grid impedance identification enables seamless switching: GFL achieves rapid power tracking in strong grids, while GFM enhances stability in weak grids. Integrated SVPWM dynamically adjusts redundant small vectors to mitigate midpoint voltage deviation. Simulation results verify the effectiveness of the proposed method which offers a viable solution for renewable integration.