This　paper　proposes　a　perturbation　estimation　based　nonlinear　adaptive　power　decoupling　controller　for　doubly　fed　induction　generator　based　wind　turbines　(DFIG-WTs).　Perturbation　states　are　defined　to　include　the　nonlinearities,　uncertainties　of　the　system　model,　the　cross-coupling　between　control　loops,　and　external　disturbances.　Perturbation　observers　are　designed　to　estimate　the　fast　time-varying　perturbation　states.　With　perturbation　estimation,　the　DFIG-WT　system　is　fully　decoupled,　and　an　output　feedback　control　can　be　designed　for　the　control　of　rotor　currents.　Rotor　current　references　are　calculated　based　on　the　steady-state　relation　between　active/reactive　power　and　rotor　current,　and　stator　dynamic　is　ignored.　The　performance　of　the　proposed　controller　is　evaluated　and　verified　via　both　simulation　and　experimental　tests.　©　2019　IEEE.