Research On Maximum Power Point Tracking(MPPT) Method Of Direct-driven Permanent Magnet Synchronous Wind Turbines

In terms of the “’second five’ development of wind power technique specificplanning” published by science and technological department on April2012, the maintarget of the basic research of wind power industry in our country is to promote the designability for wind turbine and wind farm, which make it complete. Furthermore, it solves theimportant science questions based on the air condition in our country that are basictheoretical research of wind energy resources and wind power system. As the importantresearching task in basic theory of wind power system are also mentioned in “specificplanning”, their studying includes the wind turbine modeling, the methods of verificationand simulation theory and the methods of establishing the integral dynamic mathematicalmodel for wind power system. Comparing with the traditional types of double-fedinduction generator, the direct-driven wind turbine generator is concerned by their lowconsumption, high working efficiency and low maintenance investments. In addition, dueto the direct-driven wind turbine generator has begun to be put into use in large quantities,improving the efficiency of power extraction in wind and power system throughcomprehension their working characteristics become the main researching object in windand power industry.In this paper, due to the preliminary understand and analysis of the dynamiccharacteristics in the direct-driven wind turbine generators, there are working in severalsteps. Firstly, to establish the mathematical model by its modeling mechanisms operate inthe Matlab/Simulink to build up the simulation model for whole wind turbine generators,which include the model of wind velocity and wind turbine generator, the model ofdirect-driven wind turbine generator. Among these conditions, the model of wind velocityproposes a method that completes the natural wind. According to the wind frequencydistribution curve reported by the wind resources assess in certain wind power industry and,following the Rayleigh distribution randomly deploy in certain different wind velocity sign,they establish the simulation model with natural wind velocity, which randomly assign thewindy velocity, at the same time, cover the cut-in speed to the cut-out velocity range. Inaddition, the probability of wind speed conform the Rayleigh distribution in certain rangeof time. In the controlling aspects, the establishing model for mathematical model indirect-driven wind turbine generators may complicated and hard to complete. So, to achieve the direct-driven wind turbine generators controlling apply the method ofsimplifying by using the coordinate transformation. The next, when machines are operatedbelow the condition of rated wind speed, this project mainly research on the maximumpower tracking to establish the simulation model of the tip speed ratio method andclimbing method in terms of the three basic methods of maximum wind energy capture. Atlast, through the results analysis of simulation experiment, it accurately verify thecorrectness of wind turbine models, and when the wind speeds are below the rated windvelocity, comparing the tip speed ratio method and climbing method will perfectlydemonstrate the performance of maximum power tracing control method.