Research On Control Strategy Of Variable Speed Constant Frequency Wind Power System

As conventional energy in shortage and environment pollution problem more serious, it is very important to utilize wind energy which is very rich and non-polluted on the earth. Thanks to that more and more countries all over the world pay more attention to it, Wind power technology is improved greatly, coming out many types of wind power generators. Among them, variable speed constant frequency (VSCF) wind power system becomes the mainstream model. Compares the constant speed constant frequency (CSCF) system, variable speed constant frequency system allows the wind turbine to take the variable mode to enhance the wind utilization factor, which can achieve better result. The VSCF wind power system is widely applied in large capacity interconnected running wind-electricity unit, making it to be an important direction for future development.First of all, this article studied control strategy of variable speed constant frequency system after extensively analysis the relevant information at home and abroad. The composition of the wind turbine, the function of the control system, the basic theory is introduced. Different control strategy has been carried out when the wind turbine run in the different state. Last, a special simulation software GH Bladed for wind power system was used for modeling and simulation.Then the special environment and request is considered for the variable speed constant frequency system, the synchronization brushless wind-power system is proposed, profit from the existing correlation technique--thermal power, hydropower, wind power and so on. "High speed and the synchronization generator, brushless and the revolving excitation, the full power convertor" as the core technologies route, the revolving excitation is used to remove the hidden danger which the unsafe factor——link brings. The full power convertor technology is used to obtain the high grade electrical energy.Research on it has been done thoroughly from theory to practice, and simulation to experiment platform. This subject is also an important part of the project-- development and industrialization of control system for the brushless synchronization generator wind turbine by shandong province Changxing Wind Power Technology Co.Ltd. In the paper, three kinds of realization is carried out in detail, such as the of computer model, the experiment platform, the actual wind power. At present, this wind power system has been operated in the Tongliao wind electric field of Neimenggu province, and runs well. The results further show that the program is viable, practical and superior.Moreover, along with the capacity unceasing enlargement, the influence of the wind-power system to the electrical network is getting bigger and bigger. The low voltage ride through technology receives the universal attention. This article in view of the characteristic of present mainstream unit--double-fed and full power convertor system, carries on the analysis on existing problems in low voltage ride through, and increases the protection circuit in order to strengthen its low voltage ride through ability. It can not only maintain the electrical network stabilization when it breakdown but also have a good capacity of low-voltage crossing ability.