A Grid-Connected Solid Oxide Fuel Cell with Neutral-Point-Clamped Inverter and Mppt Control

Solid oxide fuel cells (SOFCs) are recognized for their high efficiency, fuel flexibility, and stable power output, making them suitable for clean distributed generation applications. To achieve effective grid integration, SOFC systems require advanced power electronic interfaces to convert low DC output voltages to grid-compatible AC levels while maintaining performance and stability. This paper presents a grid-connected SOFC system employing a two-stage power conversion architecture, consisting of a high-gain DC-DC converter and a neutral-point-clamped (NPC) inverter. A maximum power point tracking (MPPT) control strategy is developed to optimize power extraction from the SOFC under varying load and fuel conditions. Unlike previous approaches, the proposed MPPT algorithm is specifically tailored for SOFCNPC inverter systems, enhancing dynamic performance and improving energy conversion efficiency. Coordinated control of the DC-DC and DC-AC stages ensures seamless power transfer and compliance with grid requirements. Detailed simulations are performed to evaluate the system's dynamic response, voltage regulation, and power quality. The results demonstrate reduced voltage ripple, improved power transfer efficiency, and enhanced overall performance, validating the effectiveness of the proposed control strategy. The findings support the feasibility of SOFC systems interfaced with NPC inverters as a reliable and efficient solution for grid-connected distributed generation. The proposed approach contributes to advancing the integration of fuel cell technologies into modern power systems.