Determination of multi-objective optimization control variable domain value in coordinated control system of coal-fired unit

The accuracy of the variables variation scope in fitness function of the multi-objective optimization have an important influence to multi-objective optimization results. Take a 300 MW coal-fired unit as an example, according to the system mechanism builds a boiler-turbine dynamic model. And put forward a method, in this paper, which is using the iteration way and observing its physical significance to determine control system variables scope. The simplified model uses fuel value, turbine value and feedwater value as the inputs, and uses power, feedwater flow and absorbed heat of water wall as the outputs, to get the boundary of the pressure and the control value of the inputs during 50%-100% load.