Stress Management of Wind Turbine Components Using a Nano-Enhanced Phase Change Material Integrated Power Module

Offshore wind turbine components endure high mechanical and thermal stress due to fluctuating wind conditions and harsh marine environments, but lack coordinated stress management due to the low thermal inertia of the power electronic system. Frequent and large pitch movements further aggravate component stress. This article introduces a power module packaging method that integrates nano-enhanced phase change materials (PCMs) to provide short-term overload capability. By mixing PCMs with carbon nanotubes, the thermal resistance per insulated gate bipolar transistor (IGBT) of the nano-enhanced PCM module is reduced by 34% and 14% compared to the conventional module and PCM module respectively due to the increased thermal conductivity of PCMs. Finite element analysis and experimental results demonstrate the superior thermal performance of the nano-enhanced PCM module over traditional modules. Based on this improved functionality, a stress management strategy is proposed to mitigate mechanical stress on the pitch system by increasing the rated wind speed and temporarily overloading the turbine powertrain system. Statistical analysis based on real wind speed profiles validates the strategy's effectiveness, showing a reduction in the number of pitch angle cycles by up to 86%.