Online Evaluation of Power Device Aging during AC Power Cycling

Power devices are widely used in high-voltage converter valves as a core component. At present, standard aging test evaluate devices' reliability by using Direct Current (DC) power cycling test, without the converter conditions of high voltage and switching. Many researchers pay more attention to the actual aging of devices under converter conditions, which is called Alternating Current (AC) power cycling. Due to the complexity of AC power cycling control and the accuracy of junction temperature, it's difficult to achieve online measurements that includes measuring Rth and Vce% and evaluate power device junction temperature accurately at present. In this article, an AC power cycling circuit with accuracy junction temperature measurement is proposed. The equipment's novel features have special circuit and control strategy. A experiments and simulations of package and chip are tested for comparing the difference between AC and DC power cycling.