基于希尔伯特变换的自传感电磁轴承实现

Self-sensing active magnetic bearing using Hilbert transform

针对以往自传感主动电磁轴承系统中存在的位移解调器精度不足、存在相位滞后等问题,提出利用希尔伯特变换的转子位移估计策略.相比以往方法,使用希尔伯特变换对电流纹波基频分量幅值的提取更精确,相位延迟更小.针对自传感电磁轴承系统需要多路信号实时处理的特点,利用现场可编程门阵列（FPGA）并行运算的特性保证了各自由度位移估计信号的时序同步,搭配浮点运算功能强大的数字信号处理器（DSP）实现了自传感电磁轴承系统的反馈控制器.在4自由度径向电磁轴承刚性转子系统平台上进行实验验证.实验结果表明,FPGA模块提取的转子位置估计信号具有良好的线性度和实时性,实现了4自由度径向电磁轴承在转速为0~2 000r/min时的自传感稳定运行.

A position estimation algorithm using Hilbert transform was proposed according to the accuracy and phase delay problem of the rotor position signal demodulator in former self‐sensing active magnetic bearings .Comparing with former methods ,the amplitude demodulation of the fundamental current ripple through the Hilbert transform contributes to better accuracy and less phase delay .The parallel processing field‐programmable gate array （FPGA） was used to establish the rotor position estimator considering the requirement of multichannel real‐time digital signal processing in self‐sensing AMB system .The digital signal processor （DSP） was served as the position feedback controller of the system .The experiment was conducted on a four‐DOF rigid rotor radial AMB platform ,which showed that the estimated rotor position signal extracted by the FPGA module performed well both in linearity and real‐time property .The stable operation of the four‐DOF radial AMB within rotor speed range of 0‐2 000 r/min was achieved .