Study On The Wind Power Operational Control

As more and more countries attach importance to the application of renewable energy,particularly in the global energy crisis, resources shortage, environment pollution, wind power generation will be an unprecedented development. As everyone knows, wind power has preferable ecomic and social benefits as its cleanliness and free-polution,short construction period, flexible investment and few occupation of land. With the condition of great utilize prosprect, the countries have stepped up investment in wind power, including lots of capital investment,the cultivation of technical staff,and all levels of government's encouragement and implementation of the relevant policies, get an unprecedented increase wind power technology, and power generation equipment is becoming more and more conform to the requirements of the quality. At present of wind power generation technology, the doubly-fed induction generator system with frequency conversion constant speed is one of the main development direction. With the continuous increase of unit capacity, the total installed capacity of the scale is also growing, so the grid technology is more and more of strict requirements. This paper is based on the theoretical analysis, After each subsystem simulation model is set up, analysis of its feasibility stability by MATLAB simulation.This paper firstly introduces the present situation and the development trend of wind power in our country, research the practical significance, summarise the content of the paper.Then state the construction of doubly fed induction generator system, analyzes its components,brief description the four main relation of wind speed, including basic wind, random wind,gust and step wind, introduces the basic formation principle of this four types of wind speed and the corresponding mathematical expressions; and determines the accuracy of model by simulation, and then describes the operational principle of the wind turbine, it is converted the wind energy to another form of mechanical energy of rotating device, its input is the wind speed on the blade to produce mechanical energy, thus output mechanical torque, and use the mathematical expressions to establish the simulation model, then analyse the power generation of doubly-fed motor, before the no-load grid-connection, doubly-fed motor stator winding use grid switch to directly connected the electricity network, rotor winding are achieved by bidirectional voltage converter and power network energy flow to each other, get the dq synchronous rotation coordinate mathematic model of doubly-fed motor by coordinate transformation, coupled with some control strategy, such as based on stator flux oriented of vector control, decoupling control its power to achieve steady. By modeling each subsystem,and to achieve the establishment of grid structure model in the MATLAB/Simulink, after install each parameters, then obtain the simulink curve of the whole system, through analysis the simulink curve, in vector control model,the output power of doubly-fed induction generator system will be good at to track the rotor speed, to follow the change of rotor speed to change,and also verified the realationship between the utilization coefficient of wind energy and wind turbine output mechanical torque.The analyse shows that operationral doubly-fed induction generator system can be maintained good output effect through vector control technology, by contrast with the absence of vector control system simulation model,we can see that vector control technology can be a certain degree of utility in the control system,which verified the rationality of the control system.