SiC 3L-ANPC 电路开关瞬态过程机理与解析建模方法研究

The silicon carbide three level active neutral point clamped (SiC 3L-ANPC) converter exhibits outstanding advantages in medium voltage and high capacity applications. However, compared with traditional two-level converters, there are relatively more stray parameters in 3L-ANPC circuit. Under the combined effect of high du/dt, di/dt and multiple stray parameters, it is prone to severe device voltage and current overshoot and oscillation, which increase switch losses and restrict its power handling capability. Accurate quantification of the switching transient is of utmost importance for the finely design, proactive operation regulation, safety protection, EMI suppression, and lifetime prediction of the converter. Based on the analysis of the commutation mechanism of SiC 3L-ANPC converter, this paper proposes an analytical modeling method for 3L-ANPC circuit switching transients. The proposed modeling method can accurately predict the switching transient behavior of SiC 3L ANPC converters by only calculating the circuit states at a few specific moments. Each moment has a clear physical meaning and good universality. Experimental results validate the effectiveness of the proposed modeling method, with a maximum calculation error of less than 6% for transient overshoot and a computation speed improvement of over a hundred times compared to commonly used modeling methods. Finally, guidance is provided for the design of circuit parameters in SiC 3L-ANPC inverters to suppress overvoltage based on the achievements of this research.