... supplied by the wind turbines. The works on the quality standards of the power supplied by the wind turbines began in 199 5 by the IEC. At the end of 199 8 there was already a draft of the IEC 61400-21. ... Trans. On Power Systems, Vol. 17, Nº 3. Wind Farm – Impact in Power System and Alternatives to Improve the Integration 44existent. This effect added to the great inertia of the rotor makes ... solutions in electric power systems, IEEE Trans. on Power Apparatus and Systems, Vol.PAS-102, No.3, (May 198 3), pp. 1115-1123. Wind Farm – Impact in Power System and Alternatives to Improve the Integration...