基于感应电机电流谐波频谱分析的无速度传感器的速度辨识

基于电流谐波频谱分析的无速度传感器速度辨识方法提高了速度辨识性能,尤其是在低频情况下,这种速度辨识方法优点更为突出。由转子斜槽和转子偏心率产生的谐波和速度信息相关,此信号可以通过数字信号处理获得。这些谐波存在于任何非零转速情况下,且与随时间变化的参数(如定子绕组电阻)无关。频谱估计可以对决定转子速度的多个电流谐波进行分析,这与滤波分析方法或快速傅里叶变化的方法相比可以使速度检测对噪音不敏感、检测精度更高。在线的初始化程序可以求出槽谐波计算所需的电机的特定参数。实验证明在频率低于1 Hz时,此速度辨识方法仍可以为参数调整或为磁场定向驱动的无传感器的磁链观测器提供鲁棒的、参数独立的速度信息,此外这种算法的性能在宽范围的变频和整个负载状态下均已做了验证。

Sensorless Speed Measurement Using Current Harmonic Spectral Estimation in Induction Machine Drives

This paper proposes a sensorless speed measurement scheme which improves the performance of transducerless induction machine drives,especially for low-frequency operation.Speed-related harmonics which arised from rotor slotting and eccentricity are analyzed using digital signal processing.These current harmonics exists in any nonzero speed and are independent of time-varying parameters,such as stator winding resistance.A spectral estimation technique combines multiple current harmonics to determine the rotor speed with more accuracy and less sensitivity to noise than analog filtering methods or the fast Fourier transform.An on-line initialization routine determines machine-specific parameters required for slot harmonic calculations.This speed detector,which has been verified at frequencies as low as 1 Hz,can provide robust,parameterindependent information for parameter tuning or as an input to a sensorless flux observer for a field-oriented drive.The performance of the algorithm is demonstrated over a wide range of inerter frequencies and load conditions.