Increasing　penetration　level　of　wind　power　integration　has　a　significant　impact　on　the　operation　of　power　systems.　Therefore,　the　influences　of　the　wind　power　on　the　small　signal　stability　and　low-frequency　oscillations　of　power　systems　have　become　an　important　issue　of　concern.　Based　on　the　comprehensive　model　of　the　doubly　fed　induction　generator　(DFIG)　wind　turbine　(WT)　system,　eigenvalue　analysis　is　employed　to　investigate　its　effect　on　the　power　system　low-frequency　oscillation　characteristic　in　a　WSCC　3-machine　9-bus　system.　The　results　show　that　the　influences　of　the　DFIG　WT　penetration　as　well　as　the　voltage　control　loop　under　three　different　operating　modes　on　the　power　system　low-frequency　oscillation　modes　are　different.　Moreover,　suitable　tuning　of　voltage　control　parameters　will　help　improving　the　inter-area　oscillation　damping.　©　2011　Chinese　Society　for　Electrical　Engineering.