1. State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University Chongqing 400030 China。 .2. Chongqing Electric Power Research Institute State Grid Chongqing Electric Power Company hongqing 401123 China
Abstract：The fault characteristics of power system is being changed by the large-scale application of doubly fed induction generator (DFIG) in wind generation. Thus, the relay protection of power system is restricted. Many researches on fault characteristics of DFIG have been conducted, but the influence of low voltage ride through (LVRT) was excluded. This paper studies the short-circuit current contributed by DFIG under LVRT control, with the emphasis on the effects of reactive power on terminal voltage. The coupling mechanism between the winding reaction and LVRT control is taken into account. The expressions of short-circuit currents before and after the LVRT control were presented by constructing the vector model of DFIG operated with LVRT control. The influence on short-circuit caused by the reactive power and its trigger time under LVRT control was analyzed. The equivalent models of DFIG before and after LVRT control were then built. Finally, the calculation method of short-circuit current of a doubly-fed wind power system was proposed.
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2017, Vol. 32 
