Conventional phase-controlled cycloconvertor, due to using line commutation method, its power factor is rather low in grid side, various reactive power compensation devices should be used in practice application. This paper designs a Pulse Width Modulation (PWM) cycloconvertor using full-controlled device Insulated Gate Bipolar Transistor (IGBT). A simulation model built by using the Matlab/Simulink software is supplied, the power factor is greatly improved by displacement factor, which is almost 1. The results of the simulations show that Fractional Frequency Wind Power System (FFWPS) based on PWM cycloconvertor can remarkably increase transmission capacity, for a 200 km/110 kV transmission line can transfer as much as 90 MW electric power. Therefore, FFWPS system greatly increases transmission capacity that demonstrates its great potential of application. Performance of FFFTS is improved especially the power system’s power factor, which is above 0.9.