Analysis on multiple factors influencing the lifetime of IGBTs of electric vehicles converters

摘要

Insulated gate bipolar transistors (IGBTs) are one of the most critical components in the Electric Vehicles (EVs) because of their complex running environment, high power dissipation and frequent junction temperature fluctuation. Therefore, it's essential to predict the lifetime of IGBTs by considering the actual factors in applications. The aim of this paper is to present a lifetime prediction method during a long-term driving cycle by considering multiple influence factors of IGBTs. The lifetime prediction model includes motor drive system, electro-thermal coupling model, and lifetime analysis. Then, taking China as an example, the multiple influence factors to the result of lifetime prediction of IGBTs such as the ambient temperature, the driving cycle, and the degradation of thermal resistance are taken into consideration. The researches show that the percentage growth to lifetime prediction for these three factors is λ_T=108.4% λ_C=124.9%, and λ_R=69.9% respectively. The predicted lifetime of IGBTs considering three influence factors in China is 3.66×10⁵ km, which is nearly 5% lower than its original lifetime that is 3.87×10⁵ km.