Effect of wind speed probability distribution on lifetime of power semiconductors in the wind power converters

Power converters are crucial components of the wind turbine generator system (WTGS), and the reliability of wind power converters is partly susceptible to the wind speed at the wind sites. The existing literatures, which evaluate the effect of wind speed on lifetime of power semiconductors, mostly compare lifetime of power semiconductors in the different wind farm and hardly obtain relationship between wind speed distribution and lifetime of power semiconductors. In this paper, a lifetime evaluation approach of the power semiconductors in WTGS considering the probability distribution of wind speed is firstly presented, and then the relationship between the probability of wind speed and the lifetime consumption of power semiconductors is obtained. The results show that the great majority of the lifetime of power semiconductors is consumed when the wind speed is equal to and higher than the wind speed which is close to the rated wind speed, however, the probability of this wind speed range is much small. Based on this observation, a new idea for extending the lifetime of wind power converters through modifying the control scheme is presented in this paper. The effectiveness of the proposed control scheme is verified through a case study.