This paper takes the doubly fed induction generator(DFIG)wind turbine as an example to simulate and analyze the transient response characteristics of a wind turbine under different wind speeds condition. Some issues related to dynamic equivalent modeling of wind farms are discussed with intensive investigations. Firstly

the wind turbines working on low wind speed are found to consume a large amount of active power during the transient process not to br ignored casually for dynamic modeling of wind farms. Secondly

more clusters may have poorer equivalent accuracy

since the transient current and active power curves of the wind turbines working on different wind speeds show nonlinear differences in amplitude

fluctuations and transient response time. Thirdly

the wind turbines working in constant-rotor-speed and constant-power zones can get clustered to a single equivalent wind turbine since their transient active power and current curves are similar to each other. Finally

for a large wind farm with long collector lines and complicated configurations

the equivalent network impedance calculated by the equivalent power loss rule is not able to guarantee the consistency of wind farm outputs between the detailed and equivalent models during the transient process. So

studies about the dynamic characteristics of the collector network impedance should be emphasized. This work is supported by National Natural Science Foundation of China(No. 51377034)

China Southern Power Grid Company Limited(No. CSGTRC-K142002)and Heilongjiang Provincial Natural Science Foundation of China(No. E201432).