About a possibility of reducing losses of energy at switching off of high-voltage IGBT devices and its circuitry energy efficiency

摘要

Article is devoted researching of a problem of switching losses in IGBT modules. It is shown that the main obstacles in a way of further increasing in frequency of switchings of IGBT are the considerable size of "tail current" and dynamic losses of inclusion and switching off. The possibility of decrease in size of "tail current" and dynamic losses of switching off due to profiling of structure of the semiconductor device by proton radiation is proved. Proton radiation of IGBT allows to create big concentration of holes near a collector, leaving other structure of a crystal without changes. At the same time losses of switching off decrease twice. Further decrease in dynamic losses becomes possible thanks to introduction to the power scheme of a four-quadrant IGBT key of the switching (snubber) transistor. The presented structure allows to unload the main power transistors and to reduce thereby dynamic losses of switching off. The preliminary estimate shows that thermal load of such module decreases by 25% in comparison with standard IGBT. Such devices can be used on the diesel- and electric trains of new generation.