Research On The Sensorless Vector Control Technique Of Permanent Magnet Synchronous Generators

This dissertation introduces the actuality and the trend of the development of wind power generation. Based on the fundamental of Variable Speed and Constant Frequency (VSCF) wind power scheme, emphatically introduced direct-drive wind power generation system, and compared the passive rectification and active rectification. Meanwhile, the mathematical models of PMSG in different coordinate system are established, and the decoupled control strategy of PMSG active & reactive output power based on rotor's position oriented vector control is discussed.This dissertation analyzes the state of the art of PMSG sensorless control, based on the analysis and comparison between many methods , Flux Observer method is used to estimate the rotor position of PMSG A modified integrator is used to observe the stator flux of PMSM, and then the position of magnetic poles can be estimated by output of observer. The modified integrator can eliminate the initial value and dc drift problems associated with the pure integrator, and achieve a better performance than lowpass filter.This dissertation studies the active rectification of direct-drive wind power generation system, deeply research on the sensorless vector control technique of PMSG The method used in this dissertation is validated by simulation.This dissertation builds experiment roof. The experimental results verify the feasibility and validity of the method.The result shows the sensorless vector control technique of PMSG is viable.