This study introduces an innovative approach to enhance the lifetime of power converters linked in a back-to-back configuration for Type-4 wind turbines. The proposed method involves periodically changing both the connection points and functions of the machine-side converter (MSC) and grid-side converter (GSC) at ultra-low frequencies. This adjustment enables shared usage of power semiconductor switch lifetime, specifically of the IGBTs in power modules and their diodes, across the inverter and rectifier modes. In addition, the method incorporates simulation-based tests to assess aging effects on semiconductors as part of the evaluation process. To validate this proposed strategy, simulations were carried out using PSCAD for modeling the wind turbine and converter systems, alongside MATLAB for developing thermal models, calculating losses, and determining expected lifetimes. The impedance parameters employed in the thermal network were obtained through manufacturer-led experimental data; furthermore, the estimated junction temperatures align with the results obtained from the manufacturer’s tool. The findings illustrate that the proposed approach can significantly improve the lifetime of wind turbine converter systems, by values of 85% or more, even if the swapping operation is implemented during maintenance work.
Alişar et al. (Sat,) studied this question.