Fault currents of doubly-fed induction generator under symmetrical fault condition

作者：Zhang, L^*; Cai, X; Guo, J

来源：Australian Journal of Electrical and Electronics Engineering, 2011, 8(1): 65-74.

DOI：10.1080/1448837X.2011.11464286

• Analytical expressions
• Doubly fed induction generator (DFIG)
• Doubly fed induction generators
• Fault ride through capability
• Mathematical analysis
• Mathematical expressions
• Squirrel-cage induction
• Three-phase short circuits

In wind power systems, the fault ride-through capability of doubly-fed induction generators (DFIGs) has become a focus of study. The analysis and computation of fault currents are of great significance for implementing DFIG fault ride-through. This paper systematically analyses dynamic responses of DFIG stator and rotor currents when three-phase short circuit occurs at stator terminals. A new approach, in which the DFIG under fault condition is equivalent to a rotor excited induction machine running in a steady-state and a squirrel-cage induction machine subjected to a three-phase short circuit, is proposed to gain the fault currents mathematical expressions. The two equivalent machines represent the particular solution and the general solution of DFIG differential equations in physical meaning, respectively. Moreover, the method of space vector analysis is introduced to achieve analytical expressions of the fault currents. The maximum rotor and stator short circuit currents, as well as the times when they appear, are demonstrated. Main components of the short circuit currents and their relations are presented. Finally, simulations on a 2 MW DFIG system are carried out, and prove to be in close agreement with results from mathematical analysis.

• 出版日期2011
• 单位上海交通大学