A Direct-drive Permanent Magnet Synchronous Wind Power Control System Research

Wind power, as a clean and renewable energy, now is gradually important to be exploited and utilized under the background of energy and environment crisis. The wind power generation is now developing rapidly in the world. Compared with the doubly-fed wind power generation systems, direct drive permanent magnet synchronous wind power generation system don’t need excitation, and wind turbine and generator can be directly coupled, saving a transmission gear box, so that it has advantages of good low-speed performance, easy control, low maintenance cost and reliable operation, which becomes a research hotspot. In the wind power system, the control system is the core for normal operation, while the control technology is the key technology of wind turbine. In order to promote the rapid development for theory research and application of wind power generation technology, the direct-drive permanent magnet synchronous wind power control system was studied in this paper.First of all, summarize the present development situation and the control theory of the wind power generation and direct-drive permanent magnet synchronous wind power generation comprehensively.Secondly, introduce direct-drive permanent magnet synchronous generator as variable speed and constant frequency wind power generation system; the double PWM converter was established as the variable flow device of this system; the mathematical model of wind speed, wind turbine and the permanent magnet synchronous generator.In order to realize the rotate speed control of permanent magnet synchronous generator, the control target which was tracked by the maximum wind power was analyzed; direct torque control technology of permanent magnet synchronous generator was researched; two degree of freedom PID controller were designed; and the particle swarm optimization (PSO) was applied to parameter tuning of the two degree of freedom PID. By using MATLAB/Simulink simulation tools, the model of the above system was built and analyzed through simulation. The feasibility of how direct torque control method is applied to the permanent magnet synchronous wind power generation system and the advantages of the new PID controllers were verified through theory.Finally, summarize the research work and point out the future research direction.