Based on the theory of fractional frequency transmission system（FFTS）， a new approach to connect wind power farms into utility networks by using FFTS is presented. All variable low-frequency wind power generated in a wind power farm is collected， long distance transmitted， and then connected to the load center by use of FFTS. By lowering the wind power transmission frequency， the transmission line reactance and the speed-increasing ratio of gearbox can be effectively reduced to save capital costs. A practical wind power farm is studied. Simulation results indicate that the proposed approach can effectively increase electricity generated by wind power farm.