The Research On Control Strategy Of Inverter In Direct-driven Wind Turbine System

Because of the increasingly serious energy crisis in worldwide and the strengthening of the hunman environmental protection consciousness, it is extremely urgent to develop new renewable energy. Wind power is an inexhaustible, clean and renewable energy and it has great potential in renewable energy which should be developed. Many countries of the world have been fully aware of the importance of wind-powered electricity generation in alleviating environmental pollution, adjusting wind energy structure and other aspects. They pay much attention to the development of wind-powered electricity generation.The variable speed constant frequency technique improves the efficiency of wind energy for the wind power generators. And with the more and more mature ac adjusting speed technology, the direct-drive wind power system improve the performance of wind power generators through directly coupled with generator rotor and wind turbine. The direct-drive permanent magnetism wind power system cancelled shaft of the gear box and the unit is greatly shorten in horizontal direction, so the stability of the unit is improved. The direct-drive wind power system does not need the electrical excitation devices, which can improves the generation efficiency and it also has merits of light weight, good reliability, etc.Firstly, this paper introduces the development of the wind power generation industry and the wind power generation technology in domestic and overseas and the classification of wind power systems in currently. The basic principle of Direct-driven wind power generation system is analyzed detailedly.Secondly, the paper introduces the topological structure of the ac-dc-ac converting circuit in wind power generation system.Then the principle of Space Vector Pulse Width Modulation (SVPWM) method for two-level topology is researched detailedly. Based on above, the control strategy of the two-level inverter in permanent magnet synchronous motor is studied.Thirdly, the principle of Space Vector Pulse Width Modulation (SVPWM) method for the three-level topology is researched detailedly. Based on above, the control strategy of the three-level inverter in permanent magnet synchronous motor is studied.At last, based on the chip of DSP2812, the control programs of PMSM are designed and part of the flowchart is given.