Abstract
The extracorporeal blood pump with magnetically levitated motor has been developed to recover cardiac function of acute heart failure patients. Rotation and levitation of the impeller are controlled by feedback of rotating angle, axial position and tilt angles that are detected by hall sensors and gap sensors. Establishment of sensorless control is required because these sensors will cause lower reliability of the blood pump. In this paper, a sensorless motor control is studied for the magnetically levitated blood pump. Rotating speed and angle is estimated based on the back-EMF calculated directly from the motor voltage and current. The levitated impeller is rotated stably using the sensorless motor control when the axial position of the impeller is shifted and the motor speed is changed as a step. The settling time of the rotation speed is 0.094 seconds when the rotation speed is changes from 600 rpm to 3000 rpm and vice versa.
