Making Full Use Of The Thermal Power Generating Unit To The Study Of The High Speed Ratio Loal Control System

For inhibiting the random fluctuation of power load or power grids or source electricity, the Power Grids requests thermal power units to expand load adjustment range and to improve the generating the generating load response rate. Limited to the object properties, the thermal power units can not change power load quickly depend on change fuel content. In order to improve the generating load response rate, the thermal power units behooves to utilize thermal storage in each of part of units legitimately. It was discovered that the units can improve the generating load response rate by setting up the simplified nonlinear dynamic model of thermal storage in each part of units and designing good control system both in coal pulverizing system and condensate system.Based on the above, For improving the generating load response rate further,the thermal storage in units must be fully used. Directed by above train of thought, the researches were carried out as follows:1 Based on the analysis on structure of thermodynamic system and working principle of coal mill and axial primary air fan, and by referencing traditional coal pulverizing system model, and by using mechanism of analytical methods and statistical analysis methods, the simplified nonlinear dynamic model of coal mill and axial primary air fan was constructed with the differential equation and its parameters had been found.For a typical 600 MW heating unit with certain model parameters, the accuracy of the model was confirmed by the disturbance experiments. Based on the above, boiler coal mill and axial primary air fan system has been Improved by using thermal storage in units deeper and the generating load response rate can be Further accelerated.2 Based on the analysis on structure of condensate system, and by referencing traditional condensate throttling System model, and by applying double objects methods of designing control systems, "boiler following Turbine " coordinated control system model has been found. The model can use thermal storage of condensate Legitimately and fully, therefore, the generating load response rate can be Further improved.3 Sub-critical thermal power units "boiler following Turbine " object and its control system was found,which includes improved thermodynamic system and condensate throttling System. On above this, the disturbance of generating load command and throttle pressure command was been simulated in Matlab,the result shows that the "boiler following Turbine " control system with improved thermodynamic system and condensate throttling System can weaken the fluctuations of throttle pressure/coal pulverizing/ opening of control valve effectively,and the generating load response rate can be Further improved.A configuration of coordinated control system was been designed in this paper, for a typical 350 MW units with the subcritical drum boiler, the accuracy of the result was certificated in effect by the disturbance experiments,it also shows that the methods in this issue provides provide supports in High-rate varying load both in theory and technology.