Research on the Short-Circuit Tolerance Enhancement Method of ANPC Converter Based on Multi Degree of Freedom Active Thermal Regulation

To address the risks of thermal runaway and device failure in high-frequency, high-voltage operating environments, this thesis proposes a multi-degree-of-freedom collaborative control architecture integrating modulation strategy, power allocation, and thermal regulation. The proposed architecture comprises four core functional units designed to achieve efficient and stable electro-thermal system operation through cross-domain coordination. First, the electro-thermal coupling real-time modeling unit establishes a dynamic mapping between device-level power loss and temperature, providing a data foundation for thermal regulation. Second, the rapid short-circuit condition detection unit employs dual criteria-current rate-of-change and amplitude-to enable swift identification and mitigation of short-circuit faults. Third, the multi-degree-of-freedom optimization control unit simultaneously coordinates modulation strategies, power distribution, and cooling systems, dynamically adjusting control parameters to satisfy performance and safety requirements. The interaction among these units forms a closed-loop control mechanism that significantly enhances thermal safety and system robustness under complex operating conditions. Experimental results validate the proposed architecture's effectiveness in improving thermal management efficiency, mitigating device overheating, and enhancing overall system stability.