Blower system speed-governed by power frequency generator and driven by straight condensing small turbine and method

The invention discloses a blower system speed-governed by a power frequency generator and driven by a straight condensing small turbine and a method. The system comprises a straight condensing small turbine, a blower, a power frequency generator and a speed governing gearbox which are in coaxial connection; the output terminal of the speed governing gearbox is connected with the input terminal of the power frequency generator to drive the power frequency generator to rotate; the output of the power frequency generator is controlled to control the rotational speed of the straight condensing small turbine so as to control the rotational speed of the blower. The system greatly reduces admission throttling loss of the small turbine to improve the operation efficiency, and gives the power capacity of the small turbine into full play to increase the operation gain. The invention also discloses a steam generator set and a method for regulating the rotational speed of a blower.