用于感应电机转速估计的感应线圈设计方法

Design Method of Search Coils for Induction Motor Speed Estimation

转子槽谐波法作为一种重要的电机转速估计方法,受电机参数影响小,具有很强的参数鲁棒性,在感应电机无速度传感器控制领域应用前景良好。传统转子槽谐波法大部分基于定子电流进行分析,而定子电流中的转子槽谐波易受电机结构限制,且幅值较小,信噪比弱,影响了通用性和转速估计精度。针对上述问题,本文提出在电机内部布置线圈感应气隙磁场中的转子槽谐波,通过研究影响感应线圈中转子槽谐波信噪比的因素,提出感应线圈布置方式的优化设计方法。在一台十五相电机上开展了仿真和实验研究,结果表明所设计感应线圈可大幅提升转子槽谐波信噪比,转速估计方法具有良好的精度。

As one of the most important methods of motor speed estimation,the method using rotor slot harmonics(RSH)has good application prospect on sensorless induction motor system,since it is hardly affected by motor parameter variation and has strong robustness to parameter variation.However,most of the traditional methods are based on RSH analysis in line current,where the rotor slot harmonics are limited by the motor structure and have small amplitude and poor signal to noise ratio(SNR),resulting in poor generality and accuracy.Aiming at the above problems,a method for inducing RSH with internal search coils is presented in this paper.By studying the contributory factor of SNR of RSH,the approaches of optimal design of search coils are proposed.Simulation and experiments were carried out on a 15-phase motor,and the results show that the SNR of RSH can be improved significantly and the proposed method has good precision.