Accelerated Testing and Data Analysis Method for Thyristor Irradiation Effect

With the extensive deployment of Ultra-High Voltage Direct Current (UHVDC) transmission systems, atmospheric neutron irradiation has emerged as a significant threat to the reliable operation of thyristors within the converter valves of converter stations. Therefore, it is essential to quantitatively investigate the effects of atmospheric neutron irradiation on thyristors in order to determine their failure rates. This paper presents a non-destructive experimental circuit that has been implemented in the thyristor irradiation experiments utilizing China Spallation Neutron Source (CSNS). In the nondestructive experimental circuit, the voltage stabilizing capacitor is not adopted and a protection resistor with resistance of tens of megaohms is utilized to limit the fault current when the single event burnout occurs. In the non-destructive experimental circuit, a voltage stabilizing capacitor is not employed; instead, a protection resistor with resistance in the range of tens of megaohms is utilized to limit fault current during single event burnout (SEB) occurrences. The experimental circuit works well. A lot of data is obtained. Two data processing methods have been compared to estimate the failure rate, and it is found that the overall data fitting method based on the simplified exponential model is suitable for our working scenario.