The composition

magnitude and damping time of short-circuit current(SCC)contributed by doubly-fed induction generator(DFIG)is very different from those of synchronous generator. The transient analysis of DFIG thus becomes a focus of research. However

the existing studies aim at a single DFIG. Because the internal system of wind farm has the networked characteristic

the characteristics of a single DFIG cannot cover the overall features caused by a large amount of turbines. This study focuses on the difference of SCC contributed by paralleled DFIGs and a single DFIG. The Kirchhoff law and characteristic equation of circuit component of the space vectors are firstly analyzed. The fundamental frequency

direct-current and speed-frequency vector circuits of DFIG operated alone and with other DFIGs are constructed through deducing the transient process of DFIG under the grid fault. Then the analytic expressions of the SCC and its correlation are proposed

and the variation pattern of the SCC contributed by DFIG under parallel operation is obtained. The effectiveness of the theoretical analysis is proved by simulations. This work is supported by National Natural Science Foundation of China(No. 51407017)and Fundamental Research Funds for the Central Universities(No. 106112015CDJXY150001

No. 106112015CDJZR155516).