直接转矩控制永磁同步发电机相位自校正型定子磁链观测器

直接转矩控制永磁同步发电具有电磁转矩和直流电压输出动态响应快等优点,但这些优点的实现需要准确的定子磁链。实际发电机参数在一定范围内随工作点变化而变化,这就要求定子磁链观测器对这些参数变化具有很强的鲁棒抑制特性。该文提出一种新型定子磁链观测器,该观测器借助有效磁链概念计算出转子磁极位置角观测值,基于此将定子磁链电压模型和电流模型联系起来,无需转子速度信息;为了进一步降低观测的定子磁链相位误差,将观测的定子电流矢量与实际定子电流矢量乘积结果送给PI调节器,利用PI输出值对转子位置角观测值进行校正。实验结果表明,采用该文提出的定子磁链观测器在无需转子速度及参数辨识情况下,对电机参数变化及模拟量采样误差具有很强的鲁棒抑制特性,可以获得准确的磁链观测值,实现电磁转矩和直流发电电压的快速而平稳控制。

A Phase Self-tuning Stator Flux Linkage Estimator for Permanent Magnet Synchronous Generators Based on the Direct Torque Control

Although the direct torque control(DTC) for permanent magnet synchronous generators(PMSG) has many advantages such as quick responses of the torque and the output DC voltage,an accurate stator flux linkage estimation must be demanded to achieve these good performances.The applied stator flux linkage estimator must be robust to PMSG parameter variations because the actual PMSG parameters vary with operation points.A novel stator flux linkage estimator was proposed in this paper.The rotor position angle was estimated based on the active flux concept in the presented estimator,and then the voltage model of stator flux linkage was connected with the current model with the estimated rotor position angle.The vector product of the estimated stator current and the actual current was sent to a PI modulation,and then the estimated rotor position angle was adjusted with the PI output in order to decrease estimation errors of the stator flux linkage phase.The experimental results show that the presented flux linkage estimator is insensitive to parameter changes of PMSG and the sampling errors of analog quantities without rotor speed and parameter identification,which ensures an accurate stator flux linkage estimation,and the torque and the DC generating voltage are controlled quickly and smoothly with the proposed stator flux linkage estimator.