Parameter Identification Of Double-fed Wind Power Generation System

Large-scale wind power generation can improve the global environment pollution and relieve the energy crisis. In-grid wind power is the most economical and effective form of wind power, but large-scale In-grid wind power has brought great challenges to grid planning and operation. How to establish a set of accurate mathematical models, identify model parameters with high accuracy and verify its applicability is very important. The research object is the double-fed wind power generation system, according to the different operating environment, including wind turbine, transmission system, double-fed generator and control system mathematical model, the corresponding parameter identification strategy and applicability verification were studied.Firstly, this paper introduced the mathematical model of the double-fed wind power generation system. The mathematical model of main components was studied on the basis of the analysis of the system’s structure, including wind turbine model, transmission system model and double-fed induction generator model, which generator model including the static model and dynamic model.At the same time, this paper introduced the core control strategy like wind turbine control strategy and generator control strategy in the control system, the wind turbine control strategy including pitch angle control and maximum power point tracking (MPPT), generator control strategy including the stator field oriented rotor side converter vector control and the grid voltage oriented grid side converter vector control.Then, the paper introduced the simulation software platform DIgSILENT PowerFactory, experimental conditions, real code genetic algorithm and parameter sensitivity. It put forward " simplified differential equation" and "overall identification" optimization identification strategies, the former aimed at the mathematical model containing of differential equations, while the latter is used to which model structure is not fully known or model which input and output variables cannot be easily measured.On this basis, identifiability analysis and parameter identification of the wind turbine model, transmission model, double-fed induction generator model and controller model were studied. There was a strict formula to demonstrate the parameter identifiability of wind turbine model, and for other model parameters, sensitivity analysis was carried out to determine the corresponding parameter identification strategy.Finally, using the thought of applicability verification, applicability and reliability of those parameter identification strategies was validated. The results above demonstrated that, the identification strategies proposed in this paper were effective, and provided a new way to solve the parameter identification problem encountered in practical engineering.