A study of IGBT rupture phenomenon in medium frequency resistance welding machine

Inverter drive resistance spot welding machines are becoming a good choice of welding because of the increased machine efficiency and output power. The DC link capacitors in spot welding equipment store a large amount of energy. In case of any failure, the IGBT in the inverter has a risk of exhibiting a violent rupture. This rupture can damage the converter, drive down time and personal injury which may lead to the machinery certification problems. IGBT failure detection and solution for protection of these failures in resistance welding machines have not been reported in literature. Literature study of the IGBT failure, rupture, fault detection and protection has been carried out for inverter drives in power applications. On the basis of the findings some protection schemes and important measures in the design of the machine have been adopted which have resulted in the reduced risk of IGBT failure.