LIFETIME ESTIMATION OF IGBT POWER MODULES FOR RELIABILITY STUDY OF WIND TURBINE SYSTEMS

In this paper, a method for lifetime estimation of insulated-gate bipolar transistor (IGBT) power electronics (PE) modules in offshore wind turbine (WT) applications is presented. The PE module is studied using a time-series WT simulation model. The WT model employs a detailed representation of the system, including a two-mass representation of the mechanical side, d-q representation of the permanent magnet synchronous generator (PMSG), and an appropriately controlled back-to-back voltage-source converter (BVSC). Additionally, in order to monitor the temperature cycling, a thermal model which considers the losses in an IGBT module has been added. The temperature cycles are counted using a rain flow algorithm and the resulting effect on lifetime is calculated using Miner's rule for damage accumulation. The system is parametrised according to current state-of-the-art offshore wind turbine technology.