To improve the unit response rate to load instruction and optimize the coordinated control system in power plants

the effect of delay time and inertia time of pulverizing system on a typical coordinated control system was analyzed

on the basis of the simplified nonlinear dynamic model of load-pressure for thermal power plants.It indicates that

reducing the delay time and inertia time can effectively improve the control performance of pressure and decrease the fluctuation scope of fuel flow.Based on the simplified pulverizer model

the influence of primary air on dynamic characteristics of the pulverizing system was investigated.The results show that keeping primary air changing with fuel flow at a constant ratio and improving dynamic overshoot of primary air can effectively compensate the negative influence of the delay time and inertia time of pulverizing system on the control system.The conclusions were applied in optimization of the pulverizing system parameters for the coordinated control system in a 660 MW unit.The control performance of throttle pressure was improved greatly.