Assessment of the Degradation of IGBTs used in Wind Turbine Power Converters by a Method based on Physics-informed Transformers

Insulated Gate Bipolar Transistors (IGBTs) are key components in modern energy conversion systems such as power grids and wind turbines. Their degradation and failure can lead to significant downtime and maintenance costs. Among various degradation mechanisms, we consider thermal stress, which accelerates material fatigue and increases the IGBT thermal resistance ( R_{t h} ), and, in turn, reduces heat dissipation efficiency, further increasing junction temperature and promoting failures. This work proposes a method based on physics-informed Transformers for assessing IGBT degradation. It combines features related to IGBT degradation, extracted by relying on physicsbased knowledge with Transformer encoders. A case study about power converters of wind turbines demonstrates that the proposed method outperforms baseline approaches, including DNN, LSTM and CNN models.

Keywords: IGBT, degradation assessment, physics-informed features, Transformer, wind turbine, power converter, reliability.