Research On The Optimization Of Coordinated Control System Of Thermal Power Unit Under AGC Mode

AGC is now used in the thermal power unit load control mode in general, in order to ensure a safety, economy, stable operation of the grid and a balance between power and power load of the power system, the grid has a high requirement on the time, accuracy and speed of the load response. However, the coordination system of large thermal power unit has many characteristics such as variable, strong coupling and large delay, If the unit can not meet the requirements of power grid, not only to the economic loss caused by the power plant, but also for the entire power grid safe operation brings hidden trouble.In this paper, the experimental results of a 220 MW thermal power plant in Northwest China are carried out, because the unit after years of operation,coordination system power output has been unable to meet the load control quality, in order to meet the requirements of the northwest power grid, the system of the unit coordinated control system is optimized to meet the requirements of the AGC. Firstly,the paper deeply studies the operation mode of AGC and the control mode and characteristics of the system, so as to understand the relevant AGC performance index of thermal power units in Northwest China; Secondly, the simulation model of the power plant is established by the mechanism modeling method,and the dynamic and static parameters of the model are determined by the data of the power plant.; Then the steam turbine Digital Electric Hydraulic system and valve working principle for in-depth analysis and research, on the basis of the valve flow characteristics in the field experiments.After the completion of the test, this paper optimizes the flow characteristic curve of the valve through the combination of LOWESS and the least square, in a previously established model with valve nonlinearity and DEH system of steam distribution function, through model comparison before and after optimization coordination system load response, obtained satisfactory effect of actual system optimization In the end, the system is tested by the load disturbance test, and the indexes are better than the AGC, The optimization effect of valve experiment is verified, and the standard of fast response load of the unit coordinated system in AGC mode, which makes the whole power plant and regional power network safe and stable operation.