Research on crosstalk noise of eddy current displacement sensor for active magnetic bearing

Aiming at the special specifications of displacement sensor used in magnetically suspended Control Momentum Gyroscope (CMG), a new type eddy current sensor (ECS), which integrates radial probes with detection circuit, is designed. Based on analyzing the principle of crosstalk noise generated by probes, a method is presented to minimize the noise through adjusting the values of capacitances to make axial probes work at different frequencies and enhance the frequency of crosstalk. The method can eliminate crosstalk noise and improve test precision of displacement. Experiment results show that the proposed method makes the rotor achieve stable suspending in the range of 0~30000 r/min and the suspending precision is less than 20 μm. This design can meet the requirement of magnetically suspended CMG.