Snubber Circuit Parameters Design for IGCT Considering Clamping Diode Reverse Recovery Process

Integrated gate commutated thyristors (IGCTs) have been equipped widely in the high-power converters for industrial applications and it is very important for IGCT safe operation to design snubber circuit reasonably. After studying the clamping diode reverse recovery transient in detail, the analytical expression about the relationship between the dynamic recovery time and the circuit parameters is derived by using differential equations based on completely analyzing the operating transient of the snubber circuit. On the premise of considering the reverse recovery process of the clamping diode, an improved design method of snubber circuit parameters was proposed to suppress the voltage peak across IGCT and shorten the snubber circuit dynamic recovery time. It is conformed that the proposed parameters design approach is available through the experiment results.