Research On Parameter Identification And Verification Of Steam Turbine And Its Governing System

The mathematical model and parameter of steam turbine and its governing system are often ignored in practical research. However, It is very important for the grid mid and long-term stability analysis, frequency performance control and governing system tunning to establish an accurate model. Throuth parameter identification for steam turbine and its governing system, not only the control system can be optimized and its quality can be improved, but also the turbine status and fault can be monitored and diagnosed, which is very important to the stability of the grid and the safety of the unit itself. The selected topic of thesis has important practical value and engineering application.Firstly, this paper expounds the working process and internal principle of the reheat condensing steam turbine, whose operation characteristics are also analyzed. The causal loop diagram and the stock and flow diagrams are established by using the theory of system dynamics. The model intuitively embodies the essence of steam turbine system, which is exactly described and appropriate complex.Secondly, according to the relevant industry standards, the field test conditions, methods and steps of the steam turbine and its governing system are analyzed. And the data collected in the field is pretreated. The improved PSO algorithm and the Fruit Fly Optimization algorithm are adopted to identify the parameter of steam turbine and its governing system based on the model framework. In addition, compared to the lumped parameter identification method previously, this paper employs the measured active power of generator to restore the mechanical power of turbine which can not be directly measured, and proposes a new method to identify the parameter of steam turbine based on the processed active power. In order to improve the efficiency of identification and ease the burden of designer, a software for steam turbine parameter identification is developed based on MATLAB GUI. The software centralizes two identification methods and is used for effective identification for the parameter of two typical units of different power plants.Finally, the simulation and verification about all identification results are studied, the effect of the generator model and boiler main steam pressure on simulation and verification is considered and some effective measures are adopted to simplify the work. All errors between the simulation and measured value are calculated and the results can meet the requirements of the assessment indexes of the latest guideline, which proves the effectiveness of the algorithms and methods adopted in this paper. The system model obtained by test modeling is consistent with the actual characteristics of the system.