差动变压器式位移传感器及其在磁悬浮轴承中的应用

针对差动变压器式位移传感器的性能及其在磁悬浮轴承中的应用，理论分析传感器与磁悬浮轴承转子之间加入不同隔层时对传感器输出的影响；对传感器进行静态和动态标定，并将其应用于2自由度和5自由度磁悬浮轴承试验台进行静态和动态悬浮。研究结果表明：该传感器测试范围在–0.5～＋0.5 mm时，线性度可达±1.38%，灵敏度为20.18 mV/μm，截止频率在800 Hz左右；理论分析加入非导磁隔层不影响传感器性能，但实际中涡流、漏磁等多方面原因将影响传感器的静动态性能；在2自由度试验台上实现磁悬浮转子2自由度的静态悬浮，不加入隔层时转子的静态位移振动峰峰值小于5 μm，加入隔层时转子的静态位移振动峰峰值小于10 μm；在5自由度试验台上实现了磁悬浮转子的高速旋转，转速为30 kr/min，不加隔层时转子两端的径向振动峰峰值为25 μm，加入隔层时转子两端的径向振动峰峰值为25 μm，但波形没有不加隔层时规则。研究结果为差动变压器式位移传感器的设计，并将其应用于磁悬浮轴承系统中提供一定的理论和试验基础。

Differential Transformer Displacement Sensors and Application in Active Magnetic Bearings

Different sensor outputs with different interlayer added between the sensor and rotor are theoretically analyzed in view of the performance of differential transformer displacement sensor and its application in active magnetic bearing (AMB) system. The sensors are statically and dynamically calibrated and applied to both two degrees of freedom and five degrees of freedom AMB systems for static and dynamic suspensions. The results show that the linearity of the sensor is ±1.38%, sensitivity is 20.18 mV/μm in the measuring range of –0.5～+0.5 mm, and the cut-off frequency reaches 800 Hz. The sensor performance is not affected by non-magnetic layers according to the theoretical analysis result, but the eddy current, magnetic flux leakage, etc. In actual applications have an impact on the static and dynamic properties of the sensor. The two-degree-of-freedom magnetic rotor can be statically levitated, the vibration magnitude of rotor in the radial direction without the interlayer is less than 5 μm, and the magnitude is 10 μm when a non magnetic-conducting thin wall is installed between the sensor and the rotor. The five-degree-of- freedom magnetic rotor can be stably suspended and rotated up to 30 kr/min, and the vibration magnitude of rotor two ends in the radial direction is 25 μm. When a non magnetic-conducting thin wall is installed, the magnitude does not change, but the wave shape is not as regular as the former one. The results provide a theoretical and experimental foundation for the design of the differential transformer displacement sensor and its application in AMB system.