Research On Control Strategy For Wind Turbine With The Direct-driven Permanent-magnet Synchronous Generator

Reducing greenhouse gas emissions and protecting the environment becoming humanity’s major task. As a representative for renewable energy, large-scale use of wind power is imperative. The mainstream models with direct-driven permanent magnet synchronous generator are the object of the research. From the mechanical part, the rectifier part and the inverter part of the wind power generation system, this paper build some simulation model and studies the main control strategy respectively.First of all,based on the prerequisite that a deep understanding of the wind turbine operating conditions and pitch control principle, this paper build a simulation model that simple variable pitch control system for large wind turbines. In under the action of wind speed that suitable for dynamic analysis, the simulation results of the proposed pitch control strategy is correctness. It is lay the solid roots for further study about direct-driven permanent magnet synchronous wind power system control strategy.Secondly, the pitch control for whole-speed range has limits the wind turbine’s speed effectively. The wind power system ensures the maximum utilization factor of wind and captures the largest wind energy ultimately by combining the observer’s speed and system parameters. Experimental results to verify the sensor-less control strategy have a practical control effect.Finally, combining quasi-synchronization principle and inverter’s grid-connected technology, this part put forward the differential-frequency connection strategy based on synchronous inverter and synchronous generator’s similar droop characteristic. And the simulation results analyzed its characteristic and its feasibility. Experimental results to verify that presented method can connect grid by friendly.