Research On Inductive Displacement Sensor For Magnetic Bearing

Magnetic suspension bearing is a kind of internationally recognized high and new technology,which is often used in various fields of scientific and technological development.The stable operation of magnetic suspension system is closely related to the performance of displacement sensors in the system.Among many kinds of sensors,inductive sensors are widely used because of their unique advantages,so it is of great research value to optimize and improve them.In this article,the inductive displacement sensor for magnetic bearing is studied,and based on the principle of the inductive displacement sensor in common use,an integrated inductive displacement sensor is designed.The working principle of differential inductance displacement sensor is analyzed.The problems existing in the structure and installation of the core of the differential inductance displacement sensor are presented,The integrated iron core is obtained by the sub-assembly type iron core optimization,which not only makes the installation easy,but also avoids the measurement error caused by the installation asymmetry and improves the measurement performance of the sensor.In accordance with the requirements of the use of magnetic suspension bearings,the size of the sensor body structure,the number of coil turns and the relevant parameters of the sensor excitation are designed in detail.Maxwell software was used to establish the sensor ontology model,and the magnetic circuit simulation and comparative analysis of the split and integrated core were carried out to verify the feasibility of the structure improvement.In view of the disadvantages of traditional diode rectification,two sets of measuring circuit schemes of switching phase sensitive detection and precision rectification are designed,The circuit model was built in the Multisim software and the simulation analysis of the two circuits was carried out to verify the rationality of the circuit.According to the design of processing integrated core making,eccentric shaft,and winding coil,use precision rectification plan and design the circuit,building integrated sensor static experiment platform,measure and record the integration of sensor input and output signal,using Matlab software fitting for the integration of sensor linearity,sensitivity,repeatability and hysteresis characteristics such as the main index,and studies the influence of different frequency excitation of sensor characteristics.The results of static experiments show that the integrated inductive displacement sensor designed in this article can meet the requirements of measuring accuracy of general magnetic bearing system and lay a theoretical and experimental foundation for the development of displacement sensor technology for magnetic bearing.