基于四阶累积量MUSIC法的感应电机无传感器速度估计

Sensor-less Speed Estimation of Induction Motor Based on Fourth-order Cumulant MUSIC Method

从感应电机定子电流频谱中提取转子槽谐波,并求得电机的转速,传统采用FTT技术,但其自身存在如频率分辨率低、抑制噪声能力弱等一些缺点。提出一种采用基于四阶累积量的MUSIC法从异步电动机定子电流频谱中提取转子槽谐波频率,进而准确估计电机转速的新方法。MUSIC法具有高频率分辨力和强大的微弱谐波检测能力,加之高阶累积量可以有效地抑制噪声,基于四阶累积量MUSIC法非常适用于感应电机转子槽谐波提取。实验结果表明,基于四阶累积量MUSIC法可以正确提取转子槽谐波频率,准确估计出电机转速,尤其在频率分辨率和抗噪声上比FFT法具有较好的优越性。

The spectrum of stator current in the rotor slot harmonics of induction motor are extracted by adopting FFT method.It has disadvantages,such as low frequency resolution,poor de-noising,frequency spectrum leakage.It is difficult to improve the measurement sensitivity and anti-noise.A new method was presented,in which the rotor slot harmonic frequency was extracted from the current spectrum of the motor stator by using HOC-MUSIC to accurately estimate the motor speed.The MUSIC method has high frequency resolution and a kind of ability for strong weak harmonic detection.At the same time HOC can effectively suppress noise.HOC-MUSIC was applied to extract the rotor slot harmonics to estimate the motor speed in serious noise case.The experimental results show that this method is feasibility and effectiveness for estimating the motor speed by extracting the frequency of the rotor slot harmonic.Compared with traditional FFT method,this method has good estimation precision and dynamic characteristic.