Doubly Fed Induction Generator Subject to Symmetrical Voltage Sags

作者：Rolan Alejandro^*; Corcoles Felipe; Pedra Joaquin

来源：IEEE Transactions on Energy Conversion, 2011, 26(4): 1219-1229.

DOI：10.1109/TEC.2011.2160397

• Doubly fed induction generator (DFIG)
• fault clearing
• fault ride-through capability
• symmetrical voltage sag

The aim of this paper is to analyze the dynamic behavior of the doubly fed induction generator (DFIG) subject to symmetrical voltage sags caused by three-phase faults. A simple control algorithm is considered and assumed ideal: the rotor current i(r) (f) in the synchronous reference frame is kept constant. This hypothesis allows the electrical transient to be solved analytically, providing a comprehensive description of DFIG behavior under symmetrical sags. The fault-clearing physics of symmetrical sags is also analyzed. That is, the fault is cleared in the successive natural fault-current zeros, leading to a voltage recovery in one, two, or three steps. This clearing process, called discrete fault clearing in this paper, results in a more accurate sag modeling than the abrupt or instantaneous fault clearing (the usual modeling in the literature). The fault-clearing process has a strong influence on the rotor voltage required to control the rotor current after fault clearing. To compare the effects of both abrupt and discrete sags, different wind turbine (WT) operating points, which determine different generated powers, are considered. This study helps in the understanding of WT fault ride-through capability.

• 出版日期2011-12