Insulation Lifetime Evaluation of Electrical Machines Under Electrical Aging and Thermal Overload Transient

The insulation system of electrical machines (EMs) might be subject to electrical stress caused by partial discharge due to higher DC bus voltage and fast switching devices. Moreover, EM for some typical aerospace applications (i.e., landing gear actuators) might operate under short thermal overload transient and the insulation system is subjected to severe thermal aging. As a result, an accurate estimation of insulation lifetime under combined thermal and electrical stress is demanded for proper reliability assessment. In this paper, accelerated electrical aging tests under extremely high temperatures are performed to derive the lifetime model and then the insulation endurance under electro-thermal stress could be estimated.