Hierarchical Adaptive Control for Power Balancing in Single-Phase CHB

Single-phase cascaded H-bridge (CHB) photovoltaic inverters are widely used in distributed PV systems due to modular design and high-voltage adaptability. However, power imbalances caused by uneven irradiation, partial shading, or module aging may induce over-modulation, grid harmonic distortion, and reduced equipment lifespan. Existing methods (e.g., reactive power injection, hybrid modulation) face limitations like excessive reactive compensation or high hardware costs. This paper proposes a hierarchical adaptive power balancing strategy. Through discrete search and Lagrangian optimization, the strategy minimizes reactive current injection while mitigating grid interaction stress. Experimental validation confirms the method's efficacy, demonstrating a 15% reactive power reduction under 50% power deviation.