Research on transient simulation model of high power diode for commutating over-voltage

摘要

Large transient surges called commutating over-voltage may be generated during the reverse recovery process of diode, which poses a severe threat to the system reliability. However, the commutating over-voltage theoretical calculations are so complicated that it is inconvenient to apply to engineering practice. The characteristics of diode commutating over-voltage are studied by using transient model simulation method. The diode simulation model including reverse recovery characteristics is created by adding a resistance, an inductance and a controlled current source to a common diode simulation model. By taking 1 kV/120 kA DC test system as the research object, the simulation model is created and a commutating over-voltage experiment has been carried out, the relative error between simulation value and measured value is within 8%. It turns out that the transient simulation model not only meets engineering accuracy requirement but also avoids complicated calculations.