The Analysis And Research On Control System Of 600MW Steam Turbine

The steam turbine is one of the main equipment in the thermal power plant, the control of the steam turbine runs through the whole process of power generation, advantages and disadvantages of the performance directly impact on the electrical network operation's safety, economy and stability.The 600MW reheat steam turbine is regarded as a researchful object in this thesis. The mathematic models of the main component assemblies such as electro hydraulic servo, servomotor, inlet steam cubage, intermediate reheater and rotor are built by using the approach of mechanism analysis, and their dynamic characteristic is simulated in MATLAB environment and the mathematic models of the main component are verified correctly. Because the steam turbine is a typical, complex heat engineering system which have nonlinear, parameter time variable and uncertain factors.At present, the examples of the advanced control strategies which are applied to the steam turbine are very uncommon, so, in this thesis, at first, the DEH system based on cascade PID control strategy is researched by simulation approach. The output curves of rotating speed and power of the control system with kinds of perturbations are given, and it's robustness is also researched by simulation approach. At second, a fuzzy control strategy is given to improve the current control strategy, a fuzzy self-tunning PID controller is designed to substitute the original power controller. According to the 600MW reheat steam turbine, after gridconnected, under the load disturbance, the new control strategie is simulated in MATLAB environment, the steam turbine's output curve of the power and speed are compared under the different distuebances, for obtain a design plans with furthermore better control performance.On this basis, According to the optimal control of modern control theory, a Linear Quadratic Regulator (LQR) based on state observer is designed to appling in the steam turbine governing system. Under the external disturbance, the controller's dynamic characteristic is simulated in MATLAB/SIMULINK environment, which provides a research direction to improve the control quality of the steam turbine governing system.The research in this thesis has a further improving control quality of the steam turbine, providind reference for put forward and researching the design methods with optimizing performance of the unit control system...