Study On Pitch Control System Based On Permanent Magnet Synchronous Motor

At present, wind energy has the characteristics of lower density, random, instability and so on, research on wind power system has been a hot point in energy technology field. Since pitch-control system is an important component of wind turbine system and pitch-control technology is the key technology of wind turbines especially in large scale sets, it is of great realistic significance to make a deep study in pitch-control technology. Based on the domestic 1MW wind turbine generator system, the electric pitch-control techniques for large scale wind turbine are analied in this paper.After the pitch controlled of wind turbine system is analied, the basic law and the structure of electrical pitch-control system is studied, electrical structure and layout of the electric pitch-control system is designed. Electrical implementing agence is designed detailedly, and important components are selected.Three stations of wind turbine:starting station, below rated power station and rated power station are analied based on the basic theory of wind turbine, pitch-control and pitch angle adjustment theory. Moreover, the pitch angles are researched under those three stations. Corresponding flow charts are given based on 1MW wind turbine.Control structure for electrical pitch-control system is proposed on the basis of fuzzy control theory. The electrical pitch-control scheme based on three closed-loops with location, speed and current control is proposed, and each regulator is detailed designed. Through Matlab/Simulink simulation and in accordance with the actual wind turbine operating conditions. Experiment is carried out separately to two conditions of normal and fault simulation under the load torque random fluctuations. In order to verify this paper control performance superiority, gives the PID simulation results. The results show that the pitch-control system can meet the requirements of accurate position, steady speed,and follow torque ripple. It has wonderful robust performance and dynamic response characteristics, and can meet the requirement of the design.The simulation model of wind turbine system-wide power control is established, and the electric variable propeller servo controller is brought into the whole system. The modulator of the pitch angle is designed as fuzzy pitch angle regulator. While wind power machine operating unit is simulated in the case of higher than rated wind speed, gained the curve of pitch angle and generator power curve when real wind speed has been higher than the rated wind speed. There are indications that, the power curve of wind power machine is smooth as well as the mechanical stress is reduced through pitch control strategy. The validity of the electric pitch control system is proved.