Aiming at decreasing the unit auxiliary power consumption rate,some newly built generator units combined induced draft fan(IDF) with desulphurization booster fan,and adopted steam turbine to drive the IDF.However,this caused changing of IDF closed loop control(stator blade + speed control),and variation of the unit run back(RB) control strategy.According to the problems occurred during the debugging and operation process of the steam turbine driven IDF control for a 1 000 MW unit,optimization measurements s...