Research On Hydropower Unit Governing System Based On Fuzzy- Variable Structure Control Theory

With the rapid construction of domestic hydropower, hydropower has a very important role in the current power grid structure. But it is difficult to ensure good control effect of the hydropower unit due to the complex nature of the system when the unit is switched and in disturbed conditions. To be able to ensure the normal operation of generating units and ensure that the entire system is able to maintain a strong adaptability and robustness there is the need for improved control strategy research. In a comprehensive summary of existing hydroelectric generating system control strategy based on the method, the paper will design a controller fuzzy variable structure control theory based on the regulation applied to the hydroelectric generating system, and the simulation results.In this paper, the status of the control strategy of hydropower units are summarized. Due to PID control strategy is usually found with fixed parameters to complete, when present nonlinear factors or fluctuations in the system, it is often very damaging in quality control. And the method cannot be used as a reference to the internal state of the system variables, and the lack of inside information, it is difficult to achieve the desired control effect.According to the operating rules of regulation system of hydropower unit in hydropower station, establish mathematical model of control system of each element and the establishment of mathematical model of the whole unit control system. In response to reflect the internal state of the unit system, selection of state variables, the establishment of unit state equation, as the basis for the following simulation.In the analysis of the variable structure control theory in the control field of the advantages and shortcomings on the basis, and the chattering problem arising in the theory of structural control, the input parameters of the fuzzy controller through fuzzy reasoning is used to tune the controller of variable structure, in order to weak signal, carries on the optimization. The fuzzy control and variable structure control of their respective advantages together, in which reflects the variable structure control theory and robust at the same time, the theory of variable structure control and weaken the chattering produced to design fuzzy controller, which is combined with variable structure; finally the method is applied to the regulation of hydroelectric set in the system, operation of hydropower generating units in different working conditions under different load disturbance, through the MATLAB simulation, to illustrate the variable structure controller has very good robustness advantages of hydro turbine regulating system, the control effect is improved.