Predicting the power module cumulative damage degree in new energy vehicle: Improved Manson model

Abstract

The cumulative fatigue damage degree is a core parameter used to evaluate the service life of an IGBT module and accurately calculate the cumulative fatigue damage degree. This study is necessary to accurately evaluate the cumulative fatigue damage of insulated gate bipolar transistor (IGBT) power module in drivetrain system to improve the reliability of stable operation of electric vehicles. Especially, the improved Manson model calculates the cumulative fatigue damage of IGBT more accurately. The reliability of IGBT module is effectively evaluated to make the effective operation and maintenance strategy of drivetrain system in electric vehicles, and improving the reliability of electric vehicles. The limitations of the Manson model were considered, and an improved Manson model was proposed and the spectrum of temperature load was obtained by the rain-flow counting method of junction temperature-time curve. The cumulative fatigue damage of IGBT module was calculated using the improved Manson and Miner models. The results revealed that in situations 1 and 2, the total damage calculated by the improved Manson model was 230.25% and 8.39% higher than that of the Miner model. The working period was segmented. The results indicate that the damage degree calculated with non-segmentation was greater than that with segmentation. The total damage calculated by the improved Manson and Miner model was closer to the true value than that calculated by the Miner model.