Comparative Analysis of Power Semiconductor Thermal Stress in DC and AC Power Cycling

Power semiconductors are gradually evolving towards lower cost, higher efficiency, higher power density, while they are considered to the most important component in the field of power electronics. Therefore, accelerated power cycling testing of power modules under different temperature stresses is required, where the accurate mapping of junction temperature becomes an important part. In this paper, theoretical analysis is carried out for both the DC and AC power cycling, in which the power dissipation and thermal stress of power semiconductor devices are in focused. Detailed derivation of the relationship between losses dissipation, junction temperature, and temperature swing are presented. At the same time, the differences, advantages and disadvantages of DC power cycling and AC power cycling are compared and analyzed. PLECS simulation is used to verify the correctness of the theoretical models.