基于改进的形态滤波器信号预处理的感应电机定子磁链信号获取方法的研究

RESEARCH ON ACQUISITION OF STATOR FLUX OF INDUCTION MOTOR BASED ON IMPROVED MORPHOLOGICAL FILTER SIGNAL PRETREATMENT

该文提出了一种适合于滤除正、负脉冲干扰的基于形态滤波器的数字滤波方法。该方法具有附加相移小、成本低、可靠性高的特点,用以滤除交流电机无速度传感器矢量控制系统中相电流波形上的脉冲干扰,并且与其他种类的线性和非线性数字滤波方法如平均值滤波、中值滤波相比较,给出了对比实验波形。矢量控制系统中的定子磁链信号由对反电动势积分得到,针对应用纯积分器带来的直流漂移问题、初值问题和磁链失真问题,提出了一种新的带饱和特性反馈的积分方法,饱和阈值可以根据估算的速度实时调整。仿真和在以ADMCF328型DSP为核心的系统实验证实了该方法的有效性。

A novel morphological filter based digital noise removal method most suitable for eliminating positive and negative pulse disturbance is presented. This filter incorporates the advantages of little additional phase shift, low cost and high reliability. It抯 used to eliminate the pulse disturbance of phase current signal in speed sensorless vector control system of induction motor, and compared with other linear and non-linear digital filters such as moving average filter, median filter, and experiment waveforms are given. Stator flux signal in vector control system is acquired by integration of back EMF, in order to solve the drift, initial value and the distortion problem of pure integrator, a novel integration method using a kind of saturable feedback is introduced, the limiting level used in saturable feedback is adjustable according to the estimated speed of induction motor. The usefulness of the proposed scheme is successfully demonstrated by simulation and actual system experiments based on ADMCF328 DSP.