Health Condition Assessment of Base-Plate Solder for Multi-Chip IGBT Module in Wind Power Converter

The base-plate solder fatigue of the IGBT module is one of the failures of the wind power converter; however, the existing health condition monitoring method based on infrared thermography is difficult to be applied to the actual applications. In this paper, a health condition assessment method of the base-plate solder fatigue for the IGBT module is introduced based on the case temperature difference. First, according to the structure of the IGBT module, a 3D finite element model is established, and the junction and case temperatures at different delamination degrees are investigated. Second, for defining the degradation degree, identifying the steady-state process, and acquiring the case temperature, an assessment method of the base-plate solder fatigue based on the case temperature difference is established. Finally, taking the experiment of a practical wind turbine converter IGBT module as an example, the assessment process of base-plate solder of the IGBT module is demonstrated, and the results show that the proposed assessment method is correct and effective.