| With the gradual built of Three-Gorges Hydraulic Power Station and the execution of the project" electric power transmission from west to east", the hydroelectric resource is being developed at top speed and the hydroelectric occupy more and more specific weight. The continuous completion and commissioning of large hydraulic power station, as well as the continuous increasing of extra-high voltage and long distance power transmission system, deteriorate the stability control problem of hydro-electricity system. The associated study is very important and immediate.In this thesis, by the summarizing and analyzing about the present stability control study state of synchronous generator unit, it is achieved that the governor PSS (GPSS) is more suitable for the stability control of multi-machine system because of its better decoupled character than conventional PSS; the intelligence control theory is more reasonable than conventional methods to design the hydro-generator unit GPSS because of the uncertainty of mathematical model of hydro-electricity system caused by intense nonlinear character and time-variant operating mode of hydro-turbine and water-hammer effect of hydraulic system. Based on the Fuzzy Control Theory and MATLAB, the hydro-generator unit GPSS is designed. The Head-and-Tail Alternate Crossover Genetic Algorithm is proposed to optimize the parameters of Fuzzy GPSS. The effect of Fuzzy GPSS improving hydro-electricity system stability is studied based on the simulation model.As the basic work of the designing and evaluating of Fuzzy GPSS, the mathematic models of simple hydro-electricity system stability analyzing and controlling are founded and summarized which include the linearized model of hydraulic system-hydoturbine based on the linearized model of hydraulic system considering elastic water hammer and the linearized model of Francies turbine, two different linearized model of single-machine infinite-bus system( k1 - k6 model and c1 - c12 model), the nonlinear model of single-machine infinite-bus system based on three-order model of synchronous generator, the model of exciting system and the model of governor. Based on these models, two kinds of linearized Simulink models and a nonlinear Simulink model of simple hydro-electricity system are founded and the latter can simulate the variation of power transmission network before and after short-circuit happened.The Fuzzy Control Theory is used to design GPSS of hydro-generator unit. The GPSS have one output and two inputs which are speed error and its derivative. Selecting triangular function as fuzzy variable's membership function, Mamdani max-min synthetic method as fuzzy inference method and centroid method as denazification method, fuzzy control rules are given according to the control expectation of governor and the experience of operating staff. With MATLAB and its Fuzzy Logic Toolbox, fuzzy inference system (FIS) of hydro-generator unit fuzzy GPSS is founded and so the Fuzzy GPSS is attained with the aid of computer.Genetic Algorithm (GA) is used to optimize quantification factor and proportion factor of Fuzzy GPSS. An improved GA that is named Head-and-Tail Alternate Crossover GA is proposed to overcome the shortcoming of conventional single-point crossover GA on the optimizing of multi-parameter system. The basic idea of the algorithm is that the bits of binary string behind the crossover point are crossed if the generation number is odd and the bits in the front of crossover point are crossed if the generation number is even. In the improved GA, it is ensured that the optimized probability of every parameter is approximately equal and so the search is speeded to a great extent. Taking ITAE criterion as evaluating function of hydro-generator fuzzy GPSS, the Head-and-Tail Alternate Crossover GA is compared to classical GA. The results show that the evolutionary rate of the former is apparently higher than the latter under a same accuracy.The effect of Fuzzy GPSS is tested using time-domain simulation method in this thesis. Usin...
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