In presented paper performance analysis of the hybrid diesel-wind energy conversion system has presented. Electrical energy is generated by the two sources one source is the diesel engine generator and the other source is the wind energy conversion system the supply is provided to the isolated load. The voltage is regulated at the load side .The electrical energy produced by the wind turbine at constant speed is connected to the specific load by the rectifier, d.c link and pulse width modulation inverter. In this work the value are assumed in the IS system. Voltage regulation is done with the use of PI controller and simulation results are performed on the MATLAB (new version).