The Effects of Neutron Irradiation on the Electrical Characteristics of High-power Thyristor

High-power thyristor, as the basic components of switch and power supply system, is widely used in large fusion device. Those applications are long-term irradiated by high-dose neutron from deuterium tritium reaction, which will lend to the change of the electrical characteristics of the thyristor and may eventually bring irreversible damage to the devices. The thyristor switch of the commutation circuit in the Quench Protection System (QPS) of fusion device is regarded as the study object in this paper. Six ABB 5STP 52U5200 thyristor devices were selected and distributed in a spherical space with radii of 20 cm, 40 cm, 60 cm, and received the neutron fluence in the range from 4.3×10
¹¹
to 0.48×10
¹¹
n/cm
²
. By comparing the electrical parameter changes of thyristor devices before and after neutron irradiation, the effects of neutron irradiation on the characteristics of thyristor are obtained. Moreover, the effect of irradiated thyristor characteristics change on the whole QPS is also been studied by accurate simulation, which provides a valuable guideline for the maintenance and renovation of QPS.