The reason for poor quality of coordination control system(CCS) and the failure of achieving the index of automatic generation control(AGC) performance examination was analyzed.Partial dynamic adaptive feedforward technique and primary frequency modulation based AGC control method were adopted to optimize the unit coordination control system.The application of optimized coordination control system on an ultra supercritical 1 000 MW power unit showed that

the unit changed its load at rate of 20 MW/min from 500 MW to 1 000 MW.The dynamic and static deviations of the unit load were both less than 1%.The deviation of main steam pressure was less than 0.4 MPa

and that of the main steam temperature was less than 6 ℃.The deviation of slight-superheat steam temperature was less than 10 ℃

the aggregative indicator of the AGC was improved dramatically.