The effect of non-magnetic metal interlayer located between the transformer core and iron on the performance of the differential transformer displacement sensor was studied. The displacement sensor output model was deduced through analyzing the generated eddy current on the added non-magnetic metal interlayer. And the influences of the non-magnetic metal interlayer conductivity, coil excitation frequency and the distance between the interlayer and coil on the sensor performance were simulated in MATLAB. The relevant experiments were taken out to validate the simulation results. The results show that the sensor linearity reached ± 1.02％ and the sensitivity was 20.7 mV/μm while the interlayer material was brass,the coil exciting frequency was 10 kHz, the distance between interlayer and coil was 0.15 mm and the test range was between -0.5 mm and ＋0.5 mm. The transformer displacement sensor sensitivity decreased 8.18％ while the linearity increased 38.7％ because of the added nonmagnetic metal interlayer. This research provides a theoretical and experimental basis for the use of differential transformer displacement sensor in magnetic bearing system mainly adopted in special applications.%针对加入到差动变压器铁芯和衔铁之间的非导磁金属隔层对差动变压器式位移传感器性能的影响进行了研究.通过分析非导磁金属隔层上产生的电涡流得到加入非导磁金属隔层后差动变压器式位移传感器输出模型,应用MATLAB仿真得到非导磁金属隔层电导率、线圈激励频率和隔层与线圈距离对传感器性能的影响;对加入非导磁金属隔层后的传感器进行静态标定得到以上参数对传感器性能影响的试验验证.研究表明:当非导磁金属隔层为黄铜,初级线圈激励频率为10 kHz,隔层与线圈距离为0.15 mm,测试范围在-0.5 mm～+0.5 mm时,差动变压器式位移传感器线性度可达±1.02%,灵敏度为20.7 mV/μm;相对于相同情况下无隔层差动变压器式位移传感器的灵敏度降低8.18%,线性度上升38.7%.研究结果为差动变压器式位移传感器应用于特殊场合的磁悬浮轴承系统提供一定的理论和试验基础.
展开▼
