Optimized Differential Self-Inductance Displacement Sensor for Magnetic Bearings: Design, Analysis and Experiment

The miniaturization requirements have been put forward to the sensors for the development of the modern industry. However, the traditional inductive displacement sensor applied to active magnetic bearings (AMBs) has complicated detection device and measuring circuit with excessive discrete components which cannot meet the requirements of the miniaturization. To remedy the infliction, an optimized differential self-inductance displacement sensor was designed for AMBs. Concretely, the operating principle of the self-inductance displacement sensor was analyzed in detail. Then the optimized structure was proposed and the measuring circuit was designed. After the designing, the performance of the sensor was analyzed. Based on the analysis and designing, a series of experiments were carried out to test the performance. The results demonstrated that the designed sensor can realize higher linearity, higher sensitivity, and wider dynamic response range than the traditional inductive displacement sensor. And it is suitable to the AMBs system, with higher rotation speed and small volume.