A physics-based turn off model and its output-characteristic analysing expressions of high-voltage soft-punch through IGBTs under extreme SOA conditions

A physics-based turn off model and its output characteristic analysing expressions have been investigated for the high voltage soft-punch through IGBTs under extreme SOA (safe operating area) conditions to depict the excellent soft turn-off behaviour in this paper. The main contributions have been made as the followings: (1) Based on the interior structure and features, one virtual capacitor and two Zener diodes are respectively employed to model its dynamic avalanche characteristic and switching self-clamping mode. (2) By using the user datasheet and typical experimental waveforms, a parameter estimation approach is developed. (3) To simulate extreme SOA turn-off waveforms of the IGBT by using MATLAB and MATHCAD program, the piece-wise analysing expressions have been given out to simulate the output voltage and current characteristics. The new model and its analysing expressions have been validated with experiments. The simulation results show a good agreement with its experimental waveforms.