Wind energy acquires reputation since the previous few decades. The importance of wind energy topic leads new investigation ranges due to the operation of turbines. The operation of the turbine mainly occurs in the generator. In this study, a MATLAB/GUI (Graphical User Interface) has been developed to compare the differences between the generator types used in wind turbines. The effect of each generator on the grid has been investigated and compared Commonly used wind turbine generators Permanent magnet synchronous generators (PMSG), double fed asynchronous generators (DFIG), squirrel cage induction generators (SCIG) and wounded rotor induction generators (WRIG) are considered. The wind turbine models are modelled using MAILAB/Simulink interface using modelling parameters under the condition of having the same 1.5 MW total installed power. Therefore, the selection of the most suitable generator and the effects of the generator on the grid (FFT analysis results) will be investigated. The user has the option to determine the wind speed, pitch angle and generator parameter values of the simulation.