The Control Strategy Of Wind Power System Based On Direct-drive Type Of PMSG

Nowadays, with increasingly development of the economy all over the world,human beings have faced a series of critical situation, such as energy crisis andenvironment crisis. The electrical industry has developed so fast that electricity is widelyused in every field of life. It is no doubt that electricity has become a part of life that Mancan not leave out with it. As we all know, fossil fuels, coal minerals and natural gas arelimited resources on the earth. According to the research, in the not too distant future,these resources will be exhausted. On the other hand, burning amount of these fossilresources to produce electricity causes serious environmental problems like the greenhouse effect. So we have to find some resources that are limitless, green and safe. Usingwind energy to produce electrical power is a good way to solve the energy crisis in acertain degree. The wind energy is very clean and can be caught everywhere.Transforming the wind energy into electrical energy has become an important research inthe world.Recently, a direct driven permanent magnet synchronous generator which is shortfor PMSG has been becoming popular in the field of wind energy system. The character ofPMSG is reliable, stable, and also the structure of PMSG is simple and easily controlled.In order to catch the maximum power of the wind energy, the maximum power pointtracking technology which is short for MPPT, applies to the wind energy system in thewind farm. Changing the wind energy to electrical energy includes two main processesthat are rectification and inversion. To accomplish these two processes needs an advancedpulse width modulation technology that called space vector pulse width modulation whichis short for SVPWM. In this paper, the wind power system uses a congtrol strategy that theprocess of rectification is built as closed loop of speed and the process of inversion is builtas closed loop of voltage.It is considered that fault of electricity grid may influence thewind energy system, so the low voltage ride through technology which is short for LVRT must be used in the wind farm. For the sake of demonstrating whether the theory of theresearch is correct, this paper shows the simulation of the wind energy system by simulinkwhich is a simulation tool of software called MATLB. And also some experiments havedone to analyze the result of the research in actual conditions.