报告题目：Reliability Assessment of Modern Wind Turbine Systems
With a steady increase of the power penetration, the demands to the wind power technology are becoming the same as those to the conventional energy sources. In order to fulfill the requirements, power electronics technology is the key for the modern wind turbine systems – the Doubly-Fed Induction Generator (DFIG) based partial-scale wind power converter and the Permanent Magnet Synchronous Generator (PMSG) based full-scale wind power converter. Since lower cost per kWh, higher power density and longer lifetime are the main concern of power electronics, this presentation aims to explore the reliability in the modern wind turbine systems. It starts with the description and design of the back-to-back power converters of the DFIG and the PMSG systems. With the established loss model of the power semiconductor device, the performance of the wind power converter is analyzed in terms of its reliability. Specifically, the lifespan of the back-to-back power converters is estimated based on their thermal stress. In accordance with the grid codes, the cost on reliability can be further evaluated with various types of reactive power injection for both the configurations. The main contribution is in developing a universal approach to evaluate and estimate the reliability for modern wind turbine systems.