Study Of Protection Performance For Wind Farms

Save energy resources and cut down the using of carbon energy,make great development of renewable energy resources became the global focus yet. Wind power with the advantage of rich resources and matured technique has beening developed rapidly in many countries all over the world. Nowadays,the scale of the wind farms extend increasingly, also strengthen the influence to the electric Grid. Hence, we need the protection system of the wind farms can provide more fit and dependable protection, the protection function of the wind farms deserve deep research.This thesis built the model of Asynchronous Induction wind Generator,Double-Fed asynchronous Induction wind Generator(DFIG) and Direct-driven Permanent Magnet Synchronous wind Generator (PMSG). According to the software of Digsilent , respectively, built the simulation model of the wind farm contains the wind generator with variable speed and unvariable speed. The wind generator in different fault circumstance with different types of single fault occurred at different place of this wind farm is simulated .Obtained the short-circuit current and voltage plot , analysed the plot in theory.Then ,take the actual wind farm contains DFIG as an example, under the software Digsilent,simulated its actual adoptive protection, analysed the action circumstance of the protection devices,evaluated the performence of the wind farm protection.To solve the problem, using adaptive relay protection as a try.The analysis results expressed that, in distributed wind farm ,when different fault types of single fault occurred at different place, may cause the protection selectivity out of order. The protection can't judge the fault location accurately, can't cut out the fault circuit only selectivity. Using adaptive relay protection may improve the protection performance . Althrough, the more accurate protection for wind farms need further study.