基于定子电流小波变换的感应电机速度估计算法的研究

提出一种基于齿槽谐波检测的转速估计算法。首先对感应电机定子电流进行小波变换,得到谱后再利用脊线检测算法提取瞬时频率,然后根据齿槽谐波频率估计转速。将该算法在感应电机无速度传感器直接转矩控制系统中进行了仿真,仿真结果表明,使用小波变换的估计算法不受电机参数的影响,明显提高了电机的转速估计精度,并且在整个转速范围内有效,从而也解决的了在低速范围内,转速估计精度低的问题。

A new sensor-less speed estimation algorithm based the rotor slot harmonic currents detecting is proposed in this paper.First,using the analytic wavelet transform of the stator current signal,the spectrum of the stator current is gotten.And then the instant frequency can be obtained from the ridge analysis of the spectrum.Then the speed will be estimated from the frequency of the rotor slot harmonics.The method is integrated into the Induction motor sensor-less speed direct torque control system.The simulation results show the proposed estimation algorithm is independent of motor parameters and the estimation accuracy is improved markedly and the algorithm is effectual in the entire speed range.