The Research On Variable Speed Constant Frequency Doubly-fed Wind Power Systems

The modern era, traditional fossil energy reserves have severity shortage, and fossil energy consumption will bring a series of environmental problems, this is urgent need to find new green renewable energy to make up for traditional energy supply, and eventually replace the traditional energy. Wind effects a renewable green energy, past due to control technology factors, such as restrictions, didn't get to good use, today with the development of science and technology, wind power has can very good on a large scale, development and utilization of the world to the wind power technology also gives high attention, and spend a lot of money to development. This thesis is in this background, variable speed constant frequency doubly-fed wind power generation system control and design theme for doubly-fed type, the basic structure and operating generator mechanism, and a thorough study of vector control methods to control the whole system.This article elaborates the use of doubly-fed generators variable speed constant frequency wind power systems superiority; Secondly introduces wind machine aerodynamic characteristics, and build a mathematical model of a wind turbine wind turbines, demonstrates that the biggest use of wind power to the principle; Again in doubly-fed generators are discussed under different wind speed of operation condition, after analyzing the basic circuit and basic principle on the basis of the stator flux linkage and using directional vector for vector control method, the paper realize doubly-fed generators of active power and reactive power decoupling control.In the variable speed constant frequency doubly-fed wind power systems the core control device double PWM converter and analyzed the basic structure and converter, and discusses the basic functions in converter and the grid energy flows between converter operation state, and constructed the mathematical model, and proposed in this foundation to voltage space vector control technology for control strategy, realized the converter can automatically according to the wind speed to complete rectifier and transformation of the inverter working state energy can and achieve in doubly-fed machine and the grid the two-way flow between.Finally using mouse cage motor wound rotor asynchronous motor with variable to simulate the constant frequency doubly-fed wind power systems, verified by the experiments related theory, realized the grid generation.