Researchonthe Control Technologyof Double-Fed Induction Generator Rotor Side Converter

Wind energy is a kind of renewable energy, which has great development potential and application value. In recent years, wind power generation system has been developed rapidly. Doubly-fed induction motor wind power generation system has a small capacity inverter, active power and reactive power can be adjusted individually, a wide range of adjustable speed, etc., in the wind power system has been widely used. In this paper, a doubly fed wind generator is studied, and the rotor-side converter control technology of the DFIG wind generator is studied.Firstly, the development status and industrialization status of wind power generation system at home and abroad are summarized. The characteristics, control strategies and advantages and disadvantages of different types of generators and their corresponding power generation technologies are analyzed and summarized. In accordance with the regional characteristics of China, Power generation requirements,put forward the topic of this paper background and significance of the topic. Then,according to the basic theory of the motor, the mathematical model of the variable-speed constant-frequency doubly-fed asynchronous wind generator is analyzed.In order to realize the decoupling control of the active power and the reactive power, the mathematical model of the generator in the two-phase rotating coordinate system and the rotor According to the performance requirements of the grid and the problems existing in the traditional control algorithm, a stator flux oriented vector control strategy is proposed, and the stator flux estimation method is described in detail. The control system is designed to control the rotor current so that the amplitude, frequency and phase of the output voltage of the DFIG are the same as those of the power grid, and output the active and reactive power.Secondly, the conventional wind turbines need to install the angle encoder on the rotor of the motor when the vector control strategy is adopted. It can detect the rotor position of the motor in real time. But the angle sensor increases the hardware cost of the motor and reduces the reliability of the wind power generation system. In order to improve the operational reliability of DFIG, reduce the motor volume and reduce the cost, this paper presents a rotor angle position estimation method based on sliding mode observer. The proposed rotor position observer combines the advantages of the traditional linear sliding mode observer and the nonlinear sliding mode observer, has the characteristics of insensitivity to parameters, high robustness and fast convergence, and can estimate the rotor position more accurately The stability of the system is proved by Lyapunov stability theory.Finally, the simulation system platform based on MATLAB / Simulink is constructed, and the validity of the proposed method is verified. The hardware debugging and test platform is built with TI DSP as the main control chip. The power driver part adopts IPM Intelligent power module drive circuit, level conversion circuit,etc., and the control algorithm proposed in this paper were programmed to achieve the final experimental results confirm the effectiveness of the proposed control strategy for the development of double-fed generator system provides A certain theoretical basis.