| As an indispansible factor of human development, energy plays a vital role in human life. Energy shortage restricts the economic development. With the increasing consumption of energy souces and the worsening enviroment pollution, we are obligatory to find a green renewable energe to substitute the traditional fossil energy. Wind power is the most developed and potential one of all these green renewable energy. Researching wind power technology is not only academical study, but also the requirement by our sosiety.Large wind farms have been fully developed since 1980', because of their scaled benefits and the particular advantages in energy saving and environment protection. However, wind power is restricted as a stochastically unconstant resourse. With the enlarging of the wind farm scale, the negative effects of wind power is becoming more and more serious and turnning to be an obstacle of further development or application. As a result of this, research on grid-connected wind turbine has become an important issue.Based on colleting, analyzing, generalizing material about grid-connectting wind power system at home and abroad, this dissertation makes an intensive study of energy management and control of wind power system based on brushless double-fed machine(BDFM). The main contents of this dissertation are as follows.In this paper, the development of Brushless Duobly-Fed Motor (BDFM) is discussed. The structure characteristics and operation process of BDFM is studied. First, different types of grid-connected generator is introduced. Then the working principle, characteristic and structure of BDFM are introduced. And also, the matehmatic model of the cascaded BDFM on the d-q coordinate rotating at rotor speed and synchronous speed seperatly, with equivalent circuit of steady state. Base on the typical equivalent circuit model of BDFM, the relations of power allocation in the operating state or generating state.The emphasis is focused on grid-connected control based on the brshless doubly-fed machine. The control strategy of the brushless doubly-fed machine is discussed. In the generating state, the mathematical model of BDFM is stochastically changeble. Comparing to other type machine, the grid-connected process of the BDFM is more complex and more difficult to control. A novel dynamic fuzzy control system based on fuzzy control theory is presented in this paper.Grid-connectting wind turbine with variable propeller pitch is introduced, and the three operation state of wind turbine is give. In this thesis, four different type wind speed mathematical model is introduced and a simplyfied wind speed model is given simulinked by Matlab. Also the mathematical transmission system of wind turbine is given.One the base of research of structure and operation principle in chapter 2 to chapter 4 the whole simulation system is established by Matlab. The purpose is to control the no-load grid-connectting wind power system by the rotational speed closed-loop. The dual converter is designed to satisfy the special requirements of the system. The simulation results are analysised to prove this control system could manage to connect the wind power system to grid safely and smoothly.At the end of this dissertation, the main research is summarized. It makes out the points of innovation and main research results, also the further researches are pointed out.
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