Development of Fluid Pump using 1-DOF Control Self-Bearing Motor for High-Speed Rotation in Liquid Nitrogen

Zero-power control is proposed for temperature drift errors in eddy-current displacement sensors used in magnetic bearing and applied to a fluid pump using a self-bearing motor. In the experiments, the self-bearing motor was cooled from room temperature to liquid nitrogen temperature, and levitation and rotation experiments were carried out in liquid nitrogen without calibration of the sensor under low temperature. The experimental results show that the control current is small and unaffected by the temperature drift error of the displacement sensor, as well as the zero power control at room temperature. It was confirmed that the zero power control can reduce the effect of temperature drift of the eddy current displacement sensor used for the control.