Research On Dynamic Self-Optimizing MPPT In The Double Fed Wind Power System Based On Equivalent Impedance Matching

In recent years, energy shortages and environmental pollution become more and more serious, so the development and utilization of wind power and other renewable energy become very important. Wind power is a kind of important renewable energy forms, which variable speeds constant frequency (VSCF) double fed wind power generation technology with its superior control performance become the hotspot in the new technology field that the world of all countries competing to develop.This paper focuses on MPPT in double fed wind power systems, firstly introduces the research background and significance, and then illustrates briefly the development status of wind energy and future trends in wind power technology. Secondly,the wind turbine's operating characteristics, operating regions and the maximum wind tracking mechanism is analyzed. Then a detailed analysis of the power's flow in double fed wind power generation systems which are running under different operating conditions has been made. Some of the problems about MPPT algorithm based on the power given are pointed out. In order to enhance and improve the performance of MPPT in wind power systems, a new MPPT control technology transplanted in the wind power systems which is EIM theory applied in the photovoltaic power systems is raised. From the similarity of the photovoltaic power generation systems and double fed wind power generation systems, the theoretical feasibility of transplanting EIM is analyzed. With the purpose of finding a kind of dynamic or static self-optimizing MPPT method in wind power systems, a detailed analysis is given.In order to prove its correctness, a simulation model of double fed wind power generation system is built. Firstly the mathematical model of the double fed induction motor is derived in different coordinate systems. Secondly the stator flux oriented vector control technology is introduced and the relevant control is simplified, and the active and reactive decoupling control block diagram is obtained. Finally the simulation model is built by MATLAB and proves part work of the theory's correctness.