Fundamental frequency and mission profile wearout of IGBT in DFIG converters for windpower

In this paper the influence of fundamental frequency and mission profile power cycles on estimated lifetime of the power semiconductors in the rotor side converter of a DFIG will be investigated. The aim of this paper is to get a feeling which impact the large cycles due to the variation of wind speed (mission profile cycles) and the short cycles caused by the output frequency of the converter (fundamental frequency cycles) have on the estimated life time of the power semiconductors. The total number of cycles, including mission profile and fundamental frequency cycles, were counted using the Rainflow algorithm. To count the fundamental frequency only the maximum and minimum temperature within one period of the fundamental frequency were extracted. The investigation was done for a real wind speed over time profile over 6 months.