Research On Distributed Wind Power Generation System Grid-connected Friendly Based On Hybrid Control Theory

A distributed wind power generation not only improves the utilization of windpower, but also avoids the loss of long distance transmission and solves thedeterioration of environment and depletion of conventional resource. Since adistributed wind power generation system is arranged directly in distribution grid, itmakes up the deficiency of a centralized energy supply system. But it has enormousinfluence on the running and control of distribution grid as well. Therefore, what kindof utility interface should be employed and how to make a distributed wind powergeneration system a friendly supplement have become a subject of interest toresearchers. The purpose of this paper is to apply hybrid control theory, a provocativetheory, to distributed wind power generation system by adopting a new utilityinterface and to realize friendly grid connection.Firs of all, current conditions and developing tendency of distributed wind powergeneration system is introduced. Then, topological structures of several types ofutility interface of several distributed wind power generation system are analyzed,which draws the conclusion that if voltage source inverter is used as the utilityinterface of a distributed wind power generation system and takes propel controltechnology to manipulate it at the same them, friendly grid connection of distributedwind power generation system can be achieved. Next, based on the introduction ofhybrid control theory, the hybrid feature of wind power generation system is analyzed;modeling and control of a distributed wind power generation system is conducted onthe basis of hybrid system; the fundamental structure of friendly grid connection ofdistributed wind power system and its hybrid global control system are provided; awind power system and its utility interface hybrid controller are studied and designed.This thesis takes variable speed variable pitch wind turbines with300KW rated poweras an example, a typical wind power network systems, and employ Matlab/Simulinkand Matlab/Simulink/Stateflow as its software platform to build simulation modelssimulation.The results demonstrate that friendly gird-tied electricity of distributed windpower can be well achieved by taking voltage source inverter as network interface andapplying a hybrid control method, which has function of reactive compensation andharmonic suppression to the system, and it also can enhance the safety and stability ofdistributed wind generation system. Finally, this thesis summarizes the full text, forecasts further work that can be conducted in the field of wind power integrationand proposes the key direction in the next step.