Research Of Grid-Connected Inverter For Variable Speed Constant Frequency Wind Power

Since the beginning of this century, with the world’s growing energy shortages and environmental problems continue to worsen, people will pin their hopes on the green-clean and renewable energy. Using various forms of renewable energy is attached great importance by countries around the world. Wind energy is one of the earliest energy people used, the most technically matured and widely used, the largest commercial development conditions and development prospects. Experts estimate the total wind energy resources around the world is about 2 trillion kilowatts annually, if we can use the wind resources fully, only 1% of the surface wind energy will be able to meet the worldwide demand for energy. Wind power and wind energy used in grid-connected application is the way of the major trends, therefore, the technology how to transform wind energy into electricity and connect grid (grid-connected inverter technology) is one of the key technologies of wind energy, It has also become current research focus areas of new energy.In this paper, deeply discussion the grid-connected inverter for variable speed constant frequency wind power generation system current widely used. First, introducing the background and significance of this research, analyzing the difference of wind power in the two kinds of ways:variable speed constant frequency and constant speed constant frequency, explaining reasons for choosing variable speed constant frequency wind power generation system as the inverter technology carrier, and then, some implementations VSCF wind power system are compared, and further this article specific subjects are determined:direct drive wind power system grid inverter technology, and then started on the detailed description and analysis of grid-technology control strategy, setting the whole inverter system control method. Controlling output voltage input current as basic control strategy, and introducing the detail of the inverter technology should realize the function based on the grid specific requirements of the inverter technology:how to produce PWM wave; how to make the inverter output current in the grid with the grid voltage synchronization; how to reduce system control process fluctuations on the grid system; how to prevent power failure occurs when the island effect; how to realize when the circuit fails to make a smooth wind power systems and power from the power supply without compromising quality. These issues have been resolved in the third chapter. In the analysis of the theory, the paper system of hardware and software control of parts of a specific are designed, made a foundation for the simulation, and finally, in order to verify the accuracy and reliability of the above analysis, system simulation experiment to verify the feasibility of this design.