Automic generation control(AGC)is an essential requirement in automatic control of power grid

the slow response of thermal power units participating into AGC is a commonly existing problem.For this

the coordinated control system of the unit has been analysed

and retrofit scheme being put forward

including optimization of load command effecting upon feed forward link of fuel control

elimination of cross limitation between air and coal

prefeed of coal

heat accumulation and pressure draw-back by using the boiler

etc.

and the said scheme has already used into retrofit of the coordinated control system of supercritical units no.1 and no.2 in Jiangyin Power Plant.Practical application shows that the retrofitted coordinated control system can rapidly respond to the load command of AGC.