基于增量式旋转编码器的永磁风力发电机控制研究

Control of a PMSG Based on Incremental Encoder in Direct-drive Wind Power System

永磁直驱型风力发电机是一种低转速大转矩的发电机,风力机运行过程中要实现最大风能的捕获,需要对发电机进行转矩控制。使用一种高精度增量式旋转编码器,测量永磁同步发电机的转速和转子位置,并在此基础上实现了发电机的矢量控制。实验表明,经过初始安装角度的校正,这种高精度的增量式码盘能够准确测量发电机的转速和转子位置,没有累积误差,基于这种编码器的矢量控制方法在永磁风电实验系统上取得了很好的效果。

Permanent magnet synchronous generator used in direct-drive wind power system is a kind of low speed and high torque generator. The torque has to be controlled during working to capture the most wind power. A high performance incremental encoder was used to measure the rotor speed and rotor position of the generator, based on which the vector control is accomplished. Through experiment, the speed and positon of the generator rotor can be estimated precisely without accumulated error, after the initial mounted position of the encoder is calibrated. This kind of control method is verified in the experimental system of direct-driven wind power system and proved effective.