Improved Coordination Control Approach For A 600MW Coal-fired Power Plant

Automatic Generation Control(AGC) is a vital manner for regulating the power generation of a unit. AGC satisfies the time-varying electricity needs of the grid and meanwhile keeps the generator set running at a very economical state by controlling the units with frequency regulation. The generator unit is required to be controlled by AGC all day long after grid connection, therefore AGC performance of a unit is an important index for evaluating the stability and the economic efficiency. As Shanghai Municipal Electric Power Company has very strict indicators for AGC performance evaluation, power generation enterprises have stringent demand on optimizing the AGC performance of their own units. The Coordinate Control System(CCS) is a main control system in a generator unit; its performance exerts direct influence on the AGC performance.A coal fired power plant utilizes the energy from coal burning to heat the water, the steam with high temperature go through a turbine to turn the heat energy into electricity. During energy transformation, perturbations from each process will affect the automatic control of the whole generator set. The thesis first discusses several main reasons of the influences on the performance of AGC when CCS takes effect; then we make enhancement plans by data analysis and simulation. This thesis optimizes several sub-systems such as the pulverized coal system, the main control system of the unit, and the water system used for cooling. Based on the trsults of the combustion characteristic test, the load characteristic test of the boiler, as well as steam temperature fluctuation test, we obtain the data of related facilities used for model validation and optimal control strategy development. Under the premise of ensuring safety during electricity generation, these optimizations are capable of adjusting loads with desirable performance while satisfying the operation scheduling and diminishing the magn-itudes of variations of vapor pressure and temperature during frequent switch of AGC load.