Investigation on the dynamic behaviors of paralleling T-type IGBT modules

The paralleling of three level T-type IGBT modules delivers unusual switching voltage and current. Influences of the temperature deviance on paralleling performance are analyzed in this paper. Turn-on behaviors of paralleling modules can be improved by certain temperature deviance. Turn-off behaviors are affected by temperature deviance in two ways, by both energy loss mismatch increases with temperature deviance. IGBT over voltage risk and di/dt risk show different trends. In addition, T-type IGBT modules have better paralleling performance as negative temperature coefficient of diode and positive temperature coefficient of IGBT compensate with each other when current flows into the neutral path. However unexpected current loop is formed when the paralleling T-type IGBT modules operated with temperature deviance. This paper provides guidance on hard circuit design of T-type IGBT modules paralleling applications.