Power Transformer Role for Gearbox Mechanical Stress Mitigation during Voltage Dips Applied to Doubly-Fed Induction Generator Based Wind Turbines

摘要

This paper presents some topological solutions for the electrical interconnection to the grid of a wind turbine using a DFIG, in order to increase the reliability and lifetime of the gearbox. The so called crowbar system is studied by numerical simulation to demonstrate its contribution to the gearbox mechanical stress. Analytical models are used to present the advantages of inserting a series voltage to the DFIG stator during voltage dips in order to decrease the unwanted oscillating mechanical torque applied to the gearbox. A global approach is used to propose the specifications, in terms of apparent power, of such a transformer.