The power module plays a vital role in the renewable energy conversion. But it is one of the most prone to fail components in the wind energy system. The thermal management has been proved to be a cost-effective mean to improve the reliability of wind energy system, but it has a dual nature. To balance the benefit and risk of thermal management, a lifetime extension strategy is proposed. This strategy considers the minimum junction temperature fixed to the lowest ambient temperature and the allowed maximum junction temperature determined by the predefined temperature swing. Then the related wind speeds of predefined temperature swing can be concentrated in a part wind speed area and the effectiveness of thermal management under each predefined temperature swing is calculated. The optimal effectiveness is chosen as a quantitative evaluation criterion to design the working range of thermal management and control target of junction temperature in a long time scale. As a benefit, the economic performance of thermal management is greatly improved in that each application of temperature control can reduce as much consumed lifetime of power module as possible. Case studies and experiments are presented for performance verification of proposed strategy. Results show that the consumed lifetime reduced by each application of temperature control is 6.04 × 10^-3%. The expected lifetime of power module is extended from 7.55 years to 22.08 years which meets the target lifetime of wind power generation system (20 years). In addition, this method only needs to be applied in the specified working range where the wind speed is higher than 9.30 m/s. Thus, the disturbance on the system's normal operation is significantly alleviated.

电源模块在可再生能源转换中起着至关重要的作用。但这是风能系统中最容易发生故障的组件之一。事实证明，热管理是提高风能系统可靠性的一种经济有效的手段，但它具有双重性质。为了平衡热管理的收益和风险，提出了寿命延长策略。该策略考虑了固定在最低环境温度下的最小结温和由预定义温度摆幅确定的允许最大结温。然后，可以将预定义温度摆幅的相关风速集中在部分风速区域中，并计算每个预定义温度摆幅下的热管理效率。选择最佳有效性作为定量评估标准，以长期设计热管理的工作范围并控制结温。有益的是，由于温度控制的每种应用都可以尽可能减少功率模块的消耗寿命，因此大大提高了热管理的经济性能。通过案例研究和实验来验证所提出策略的性能。结果表明，每种温度控制应用所减少的消耗寿命为6.04×10 热管理的经济性能大大提高，因为温度控制的每种应用都可以尽可能减少功率模块的消耗寿命。通过案例研究和实验来验证所提出策略的性能。结果表明，每种温度控制应用所减少的消耗寿命为6.04×10 热管理的经济性能大大提高，因为温度控制的每种应用都可以尽可能减少功率模块的消耗寿命。通过案例研究和实验来验证所提出策略的性能。结果表明，每种温度控制应用所减少的消耗寿命为6.04×10^-3％。电源模块的预期寿命从7.55年延长至22.08年，可以满足风力发电系统的目标寿命（20年）。另外，该方法仅需要在风速高于9.30 m / s的指定工作范围内应用。因此，大大减轻了对系统正常运行的干扰。