An Advanced 4-in Integrated Emitter Turn-off Thyristor With Ultralow Commutation Impedance to Achieve 8 kA Turn-off Capability: Comprehensive Analysis, Design, and Experiments

Compared with integrated gate commutated thyristors (GCTs), an integrated emitter turn-
off
thyristor (IETO) has a potential of higher turn-
off
current capability and requires lower power consumption for gate driver units, which is more suitable for high-power applications. Thus, in this article, an advanced design of 4-in IETO was presented. To reduce the gate commutation impedance and enhance the turn-
off
current, the turn-
off
circuit with low impedance DirectFETs was integrated into the housing. And the housing structure was carefully designed to provide a compact current commutation path. Then, a 4-in IETO prototype based on a 4.5 kV/5 kA GCT wafer was developed. Experimental results show that its maximum turn-
off
current was over 8.1 kA with an extremely short commutation time of 130 ns. And the total commutation inductance was only 0.38 nH. Additionally, the thermal and mechanical characteristics of the housing were also taken into consideration during design and verified by the thermal simulation and mechanical stress test. Consequently, according to this article, IETO has the potential to be a competitive device in high-power applications in the near future.