A study on application of integrated actuator in electro-hydraulic governing system which is a governing system without control-oil source of steam turbines has been presented. The successful application of the said control mode

in which the stagger oil valve is directly driven by the said actuator

at Beipiao Thermal Power Plant resolved completely the problem of infuencing the electro-hydraulic device due to fluid medium pollution

and enhanced successfully the reliability of unit’s operation

at the same time

provided new way and means for retrofitting electro-hydraulic governing system of medium and small units

having positive effect to developing steam turbine governing system without control-oil source and without fluid working medium.