Research On Mechinsim Modeling And Control Strategy Of Steam Turbine System In FCB Process

Inspired by the domestic and foreign blackouts accident, China’s huge capacity power grid security was greatly concerned, at the same time, as the main electric power energy the thermal power generating units starting to design and test emergency measures against crisis. When the power grid failure, if the generator and steam turbine systems are under normal circumstances, fast cut to auxiliary power is the best choice, the function is the FCB function.The unit remains some power point waiting for power grid recovery can not only connect power grid rapidly, but also reduce economic loss and equipment damage. Currently, most of the units do not have the FCB function, because of differences between equipment, this function difficult to unification, thus further study of the thermal power emergency measures in times of crisis is extremely important. Otherwise field test do harmful to units with security risks, in the form of modeling and simulation becomes the development trend of this issue.The article first analyses and summarize the trials units had already taken, summed FCB control difficulties, some control strategies and experience during the whole unit. For the thermal power turbine system, first modeled and simulated the turbine DEH system, transformed them into the transfer functions through a small deviation linearization and Laplace transform, then built simulations in the Simulink software. The models analysis the factors of the primary and secondary frequency modulation function, Over-speed protection action, Valve movement speed and closing time, then proposed control strategy in favor of the turbine speed. While the speed control operation will lead to large fluctuations in the parameters of the turbine auxiliary, so take lumped mechanism modeling method established the models of main steam pipe, steam feed pump, the deaerator, high pressure heater, use Simulink establish and simulate the models. Analyses FCB process impact to each part of the parameters with the extraction non-return valve closing, thus proposed qualitative recommendations in favor of the FCB.This subject is designed to prove the possibility of FCB simulation analysis and the value, for the subsequent research on control of the FCB.