The influence of the applied rotor voltage on ride-through capability of doubly fed induction generator

This paper presents a discussion about the large disturbance instability phenomenon of grid-connected doubly fed induction generators. The behavior of squirrel cage induction generator (SCIG) on large disturbance stability depends basically on the ability of the blade pitch angle control and the injection of reactive power during contingency on the network. However, the behavior of the doubly fed induction generator (DFIG) is also affected by the applied rotor voltage. The instability behavior of the SCIG is well documented in the literature, on the other hand this behavior is not well described for the case of DFIG. The analyses performed in this paper evaluate the effect of different rotor voltage applied during grid fault on the DFIG stability. A sensitive study using dynamics simulations was performed to determine the critical fault tolerance time. The results have shown that when enlarging the direct axis voltage the DFIG has better stability performance.