VSCF Doubly Ded Wind Power Generation Control System

With the wind turbine installed capacity is increasing, so improving operational efficiency and maximizing the use of wind energy has become an important content of the wind power generation field. So the VSCF doubly fed wind power generation system which can track the maximum wind power has become a research hot spot.In this paper, we use AC-excited of the rotor side to control the operation of the VSCF doubly fed wind power generation system, and do the research from the theory to practice then to the simulation deeply and comprehensively. This paper focuses on the works of the double-fed induction generator (DFIG), the methods of the largest wind energy capture control, the active and reactive power decoupled control, and the features of the dual PWM excitation frequency converter and so on.In this paper, at first, we analyze the operating theory of DFIG in detail and make a derivation for the mathematical model, operating characteristics, coordinate transformation and the power relations of DFIG and then propose a vector control strategy which is based on the stator flux-oriented. And all of these provide us a theoretical basis for the study of the paper.Secondly, on the base of analyzing the characteristics of the wind turbine capturing the wind energy and the operating characteristics, a new control strategy is studied, which do not need to detect wind speed and can not only capture the largest wind energy beyond the maximum wind allowed, but also can realize decoupled control of the active power and reactive power of DIFG. Finally, in the study of the DFIG rotor excitation power, we analyze the operating principle and the characteristics of the dual PWM excitation frequency converter.In the simulation, we use the software Matlab/Simulink to build the simulation model of every part of the VSCF wind power generation system, and then we analyze and compare the operating performance of the doubly-fed generator system under different wind speed. The simulation results show that the models built are correct, and the VSCF wind power generation system has good operating characteristics.