Impact of different control schemes on the life consumption of power electronic modules for variable speed wind turbines

This paper presents a real-time prognosis technique to estimate the life consumption in power modules in a variable-speed wind turbine generator. This approach is used to evaluate the expected life of power electronic modules for a range of drive control strategies in a doubly fed induction (DFIG) generator which is fitted in a variable speed wind turbine including Maximum Power Tracking (MPT), Constant Power Mode (CPM) and Constant Torque Mode (CTM). Using real-time compact thermal models which are integrated with life time models for two common wear-out mechanisms (wire bond and solder substrate) made it useful to estimate the life consumption of power modules in use. The impact of Maximum Power Tracking, Constant Power Mode and Constant Torque Mode control schemes on the life of power module bond wires and solder layers is demonstrated. The results showed that using MPT control method can affect badly the expected life of power modules simply because it generates more thermal cycling. On the other hand, both the CPM and the CTM have less impact on the life of the power modules used in DFIG converters.