The Simulation Research On Control System Of 300MW Steam Turbogenerator Unit

The control of the steam turbogenerator unit runs through the whole process of power generation. Its effect directly relates to the electrical network's quality and the unit's safety, stability, and economy.The 300MW condensing steam turbogenerator unit 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, steam power and rotor are built by using the approach of mechanism analysis, and their dynamic characteristic is simulated in MATLAB/SIMULINK environment. On this basis, the DEH system based on cascade PID control strategy which is widely used nowadays is researched by simulation approach. The approach of parameter regulating is concluded. The output curves of rotating speed and power of the control system with kinds of perturbations are given, and the system's robustness is also researched by simulation approach. The primary frequency modulation of DEH system is researched by simulation approach, too. The simulation results indicate that the modulation effect is better if frequency difference signal is connected to the governing valve than to the power controller. The rotating speed inequality rate's effect on the primary frequency modulation's characteristic is discussed. The current control strategy is improved by combining fuzzy control to PID control in this thesis. The approach of parameter regulating of the control system that uses new control strategy is given, and the control capability of the two control strategies is compared and analysed. The results show that the control system that uses the new strategy has better control effect than current system with fixed value's perturbation, steam pressure's perturbation and governing stage's perturbation. But their robustness is almost the same. A 3D model of the steam turbine is built by using 3D MAX on basis of introducing the technology of virtual reality in this thesis, and the model's corresponding VRML file is obtained. The animation effect of rotating speed is realized by using the virtual reality toolbox in MATLAB, and a reasonable assume about the remote 3D simulation for the steam turboset control system based on B/S frame is put forward. The research in this thesis has some theoretical and practical significance for improving control effect of the unit and capability of frequency modulation. It is also significative for doing the simulation work in the field of steam turbine control.