Research On Description Of Pump Turbine Characteristics And Nonlinear Control Of Reversible Unit

The Pumped Storage Power Station play the role of rapid response such as peak and valley filling, frequency modulation and phase modulation, spinning reserve. Therefore, in order to solve the peaking problem of power grid, pumped storage power station is bound to the strong development. But there are two important factors to restrict Pumped Storage Power Plant to develop, one is the description of pump turbine characteristics. The description of pump turbine characteristics is the basis of design of water conservancy, transition process analysis and study of the control law. The traditional description of pump turbine characteristics has the phenomena that guide vane opening curves intersect, focus and reverse, resulting in fitting difficult and transient process calculating multi-value. The second factor is the highly efficient and stable operation of Pumped Storage Power Station. Pump turbine has strongly nonlinear phenomena with unstable regions of anti-S region and hump region. It can't solve the adapting problem between control object's strong non-linearity and traditional linear control rule to ensure the highly efficient and stable operation fundamentally.Aimed at the problems of the past characteristics description in the plane coordinate, the description of pump turbine characteristics is studied under a new perspective of space surface. this method don't have the phenomena that guide vane opening curves intersect, focus and reverse. And then space surface of pump turbine characteristics was built on the basis of the model test data with B-spline theory. The interpolation of guide vane opening curves don't have multi-value. Drawing the feature lines of space surface of complete characteristics, this is the basis of studying the changing law of pump turbine characteristics.Aimed at the linear control theory are insufficient to meet the needs of safe and stable operation of reversible unit, reversible unit nonlinear control strategy is studied. Firstly, the transition process simulation platform of reversible unit is established, laying the foundation for the study of reversible unit nonlinear control law. Nonlinear mathematical model of reversible unit was set up in combination with the pump turbine, water diversion system, power generation motor and actuator. Numeric method for computing the transition process was studied, and the reliability of numerical calculation method is verified by simulation experiment. Secondly, in view of the reversible units of nonlinear mathematical model is established, the exact linearization theory was applied to get the nonlinear control law of the reversible unit. Simulation experiment were done under several typical large fluctuations conditions such as turbine start-up condition, pump-off condition, pump start-to-start condition. And the simulation results show that the nonlinear control rule can get excellent dynamic performance.