An IGBT behavior model suitable for series applications

IGBT series voltage balance is the core bottleneck issue in the field of IGBT series technology, and the IGBT model is the most direct and effective method to characterize and predict the voltage balance characteristics in IGBT series applications. However, the existing IGBT model is not optimized for high-voltage and large-number series connection scenarios, and cannot achieve an effective balance between complexity and accuracy of series voltage-sharing characteristics description. In response to the above problems, this paper proposes an IGBT behavior model that takes into account the key factors affecting the series voltage balancing performance to evaluate the device voltage balancing characteristics in IGBT series applications and provide guidance for the design and application of series devices. This model uses parameter fitting to describe the nonlinear junction capacitance, and takes into account the influence of temperature on parameters such as threshold voltage and transconductance. The tail current part is based on the experimental results to fit the relationship between the tail current and time and finally simulated by adding a control function and a controlled current source. By comparing the simulation and test waveforms, the superiority of the proposed model was verified. The error of the model's simulated IGBT series cumulative voltage difference was 6.25%.