一种改进MRAS的直驱永磁风力发电机控制方法

A new control strategy of direct-driven permanent magnet wind power generator based on improved MRAS

由于速度传感器安装困难,所以在直驱式永磁风电系统中,采用无速度传感器控制是一个必然的选择。考虑到永磁直驱风力发电时的风速的实时变化和功率的不稳定性,将一种改进的模型参考自适应(MRAS)无速度传感器技术应用于发电系统,引入了小信号模型,对MRAS系统的动态性能、稳定性和算法精度进行分析。采用一种参考模型电压的修正方法,通过理想的电流模型来修正电压模型的磁通观察器。该系统能准确地估测转子位置,能适应风速不停变化和间歇性等特点,具有简单易行、动态响应快、鲁棒性强的优点。样机实验结果证明了该方案的可行性。

The installation of speed sensor is difficult in the direct-driven permanent magnet wind power generation systems. So, it is inevitable to choose the sensorless control. Considering the real-time change of wind speed and instability of power, the improved model reference adaptive system（MRAS） was applied in permanent magnet motor generation system in this paper. An improved method was proposed, which used ideal current model to correct flux observer of voltage model. And the dynamic performance, the sensorless accuracy and the effect of parameter variations were addressed in the small-signal model of MRAS. It shows that the total system can adapt to the change of wind speed and intermittence of wind. The rotor position can be accurately estimated, and it also presents the advantages of simple implementation, fast transient response and strong robustness. The experimental result shows that the scheme is feasible.