Models for simulation are vital for the authenticity of the simulation. Modeling doubly fed induction generation (DFIG) for power system stability analysis has attracted a great deal of research interests in the past few years due to the wide applications of DFIG in wind power generation. The models developed by the wind generator manufacturers are not only complicated, but also proprietary and very specific to their own products. Many simplified generic models have been proposed. Among them, the current-source based model is most widely used for power system stability analysis. The validation work on this model so far has been based on the selected simulation scenarios or limited real measurements. However, there has been no systematic and theoretic analysis on the validity of the current-source based model, which may cause inappropriate applications of this type of model in real engineering practices. This paper presents the conditions for using the current-source based model for power system stability analysis; then examines the model's validity under symmetrical and asymmetrical fault conditions. Our practices for modeling and validating a real wind farm in North China confirm the validity analysis of this work on the current-source based DFIG model.