Model Building And Parameters Identification For Turbine Governor Systems Of Synchronous Generator

The Speed governor system of synchronous generator plays an important role in the frequency stability and operation control of the electric power system. With the development of the power system, there are more and more large-scale hydro generators in the systems. These hydro generators give prominence to the security and stability control of the electric network. Accurate speed governor system models allow for more precise calculations of the power system control and stability limits. It calls for the necessity that speed governor systems be modeled in detail. The desired models are those representing the actual speed governing system performance for both large as well as small system disturbances. The precise parameters that we get from the identification can help to preview the system performance and monitor the attitude of the power system, which is useful for increasing the security and stability of the system.Based on the analysis of the principal and structure, This paper introduces the method of model building for speed governor systems (take hydraulic turbine as example), then the traditional identification methods, frequency domain identification (Fast Fourier Transform / Least Square Equation) and time domain identification (Piece Linear Polynomial Function), are studied. The thesis introduces the principal of the two methods and analyzes their advantages and disadvantages in application. The paper also introduces genetic algorithm (GA) in the parameter identification that makes the nonlinear system parameters identification possible and all the parameters can be obtained immediately. The traditional GA has been improved to increase the identification speed and precise.In the project of identification of speed governor systems located in FuJian Power System, a model has been set up for a practical system. The parameters of the model have been identified based on the data got from field test by method of time domain identification and of GA respectively. The results indicate that the method of GA can validly identify speed governing systems and has the advantages of high accuracy and good convenience for operation.