中文摘要：

风电变流器中功率器件承受的热载荷具有多时间尺度特性,具体可以划分为基频热载荷和低频热载荷,不同时间尺度的热载荷将导致不同的器件寿命消耗,因而需要分别进行评估。气温的随机波动会对热载荷产生影响,因此在进行器件寿命评估时应考虑气温因素。然而现有的寿命评估方法受限于结温计算方法,仅考虑风速的变化而忽略了气温波动对寿命消耗的影响。因此,基于结温数值计算方法,利用Bayer寿命模型,以Lauswersoog和Valkenburg两个风电场2015年的气温和风速数据为基础,评估了计及气温下功率器件的可靠性,分析了气温波动对寿命消耗的影响。结果表明,长期的气温波动会增加器件的寿命消耗,并且气温波动主要影响低频寿命消耗,而对基频寿命消耗基本没影响。

英文摘要：

bPower devices in the wind turbine power converter system suffer from two-scale thermal loadings, the fundamental frequency thermal cycling and low frequency thermal cycling, and these thermal loadings introduce different consumed lifetimes. Furthermore, the fluctuation of ambient temperature influences the thermal loadings. Therefore, accurate lifetime estimation should consider the ambient temperature. However, previous studies limited by the calculation of junction temperature only consider the mission profile of wind speed but not ambient temperature. This paper adopts the Bayerer lifetime model to evaluate the effect of ambient temperature on the consumed lifetime of power semiconductors based on a numerical junction temperature calculation method considering the actual ambient temperature and wind speed of Lauswersoog and Valkenburg in 2015. Studies show that long-term fluctuation of ambient temperature increases the consumed lifetime of device, and the fluctuation of ambient temperature mainly influences the consumed lifetime due to low frequency thermal cycling, but have little effect on the consumed lifetime due to fundamental frequency thermal cycling.