Open AccessTurn‐off analysis of FS‐IGBTs based on a simplified analytical model
Author(s) -
Ding Shun,
Xing Yan,
Wu Hongfei,
Hu Haibing,
Wang Jun
Publication year - 2017
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2017.0175
Subject(s) - insulated gate bipolar transistor , matlab , voltage , transient (computer programming) , single stage , current (fluid) , electronic engineering , current density , computer science , electrical engineering , engineering , physics , quantum mechanics , aerospace engineering , operating system
Normally for IGBTs five stages can be identified during Turn‐Off transient, among which stage 3 and 4 are most complicated and time consuming in calculation, due to its intrinsically complicated physics process. In this paper, through extensive experiments, we found an interesting phenomenon that in stage 3 the slope of the driving gate voltage is linearly related to the FS‐IGBT voltage and current, which greatly simplifies modeling and calculation. In stage 4, we further simplify the model by assuming (i) no interactive effects between the redistribution current and combination current; (ii) the base excess carrier density at depletion boundary far less than that at FSL boundary; (iii) The total charge in the base only relating to carrier life time. With these simplifications, equivalent circuit for each stage with less calculation efforts is developed, and the running time of the simulation under Matlab is less than one second. A double‐pulse testing platform was built. The experimental results for both test beds with single IGBT and two IGBTs in series connection match the proposed model developed in Matlab pretty well, under quite different operating conditions, with the maximum error on both I L – E off and V DC – E off <17%.