基于霍尔负序解调法的无轴承永磁薄片电机径向位移检测方法  

Radical Displacement Detection Method Based on Negative Sequence Demodulation Method on Hall Signals of Bearingless Permanent Magnet Slice Motor

作　　者：张艺 王宇[1] 张成糕 ZHANG Yi;WANG Yu;ZHANG Chenggao(College of Automation Engineering,Nanjing University of Aeronautics&Astronautics,Nanjing 210016,Jiangsu Province,China)

机构地区：[1]南京航空航天大学自动化学院,江苏省南京市210016

出　　处：《中国电机工程学报》2023年第19期7659-7668,共10页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51977107);航空科学基金项目(2020HKZ0001);江苏省六大人才高峰项目(XNYQC-005)。

摘　　要：传统的无轴承薄片电机系统由于存在位移传感器,难以满足心脏泵等医疗器械高精度、高集成的需求,已有基频位移自检测算法采用传统幅值解调法,对于低极对数电机难以实现两方向位移的解耦,同时需要低通滤波器滤除无效信号,存在延迟长以及误差大的缺陷;高频注入法利用的是电枢磁链之间的互感,并没有利用永磁体磁链,信噪比不高,难以实现稳定悬浮。基于此,该文提出基于霍尔负序解调法的位移检测方法,利用基频永磁磁链与检测霍尔的互感获取位移信息,通过特殊的负序正弦调制霍尔信号并求和的方式,直接解除转角在霍尔信号中的耦合,瞬时解算位移信息,位移解算精度高且无延迟,适用的转速范围宽。该文首先建立磁路模型,通过理论及仿真分析霍尔感应磁链和位移的关系;其次,给出负序解调法的详细数学推导过程并推广至其他极对数电机;最后,在平台上完成已有的两种位移检测算法与所提算法的实验,实验验证所提算法在宽速度范围内的有效性。The traditional bearingless permanent magnet slice motor system is difficult to meet the high precision and high integration requirements of medical instruments such as heart pumps due to the displacement sensor.The existing fundamental frequency displacement self-detection algorithms adopt traditional amplitude demodulation method.It is difficult to decouple the two-direction displacement for motors with small pole-pairs number.Also it requires low-pass filters to filter out invalid signals,resulting in long delay and large error.High frequency signal injection methods make use of mutual inductance between armature flux instead of permanent magnet flux,the signal to noise ratio is low so stable suspension cannot be achieved.Based on this,this paper proposes a displacement detection method based on negative sequence demodulation method on Hall signals.The mutual inductance between permanent magnet flux and hall sensors is used to obtain displacement information at fundamental frequency.By multiplying the three phase negative-sequence sine signals and summing up,the angle in Hall is decoupled and the displacement information is extracted instantly.Therefore,the method has high accuracy,wide speed range and no delay.Firstly,the magnetic circuit model is established,and the relationship between flux induced by Hall and displacement is analyzed theoretically,small details are corrected by the subsequent simulation results.Secondly,the detailed mathematical derivation of negative sequence demodulation method is given and extended to motors with different pole pair numbers.Finally,two existing displacement detection algorithms and the proposed algorithm are tested on the platform,experiments verify the effectiveness of the proposed algorithm in a wide speed range.

关 键 词：无轴承永磁薄片电机 悬浮控制 径向位移检测 霍尔传感器 负序解调法 信噪比 

分 类 号：TM341[电气工程—电机]