The paper discusses the characteristics of diffcrenl variable speed constant frequency (VSCF) wind farms whose engineering applications are realized by power system analysis software pickage (PSASP) user-defined model. The operation characteristics comparison between doubl)-fcd induction ReneratorfDFIG) wind farm and dircct-drive permanent magnet synchronous generator (PMSG) wind farm which are widely used in china is illustrated by means of simulation the influencecaused by find farm linked to power system. The result shows that voltage fluctuation curves and system frequency response curves between Iwo wind farms are almost the same when wind speed changes, however, the voltage stability and frequencyliability of DFIG wind I farm is belter tban that of PSMG windfarm when power system faults.