Study On Operation Characteristics Of Grid-connected Doubly Fed Induction Generators

With the proportion of the installed capacity of wind power generators in the grid increasing, the impact of wind generators on the grid can't be ignored. It's necessary to study the operation characteristics of wind power generators and their influence on themselves and the grid to assure that the grid-connected wind generators and the grid can run on the safe side. This thesis focuses on the doubly fed induction generator (DFIG), the detailed model of DFIG is established based on the analysis of its working theory. The operation characteristic of DFIG is studied, a new control strategy to improve the uninterrupted operation capability of DFIG is put forward and validated by simulation. Moreover, the impact of DFIG on the squirrel cage induction generator (SCIG) running in parallel with DFIG is also studied, and next the transient operation characteristics of DFIG and SCIG with different capacity proportion in a fixed-capacity wind farm are also studied.