Bearingless brushless direct current motor and control method thereof

Abstract

The invention discloses a bearingless brushless direct current motor and a control method thereof. The motor is characterized in that: a permanent magnet is uniformly distributed on a surface of a rotor iron core with a Halbach array; both a torque winding and a suspension force winding employ a short pitch winding structure and are wound round a stator tooth together; coils of each two suspension force windings are separated by a stator tooth; through a difference between a given rotating speed and an actual rotating speed and through a PI regulator, a current given value of the torque winding is outputted to control torque winding input current, and rotating speed closed loop control is realized; through a difference between a given rotor radial displacement and a detected actual displacement and through the PI regulator, a suspension force given value is outputted to control suspension force winding input current, and rotor radial displacement closed loop control is realized. By employing the method in the invention, effective control of bearingless brushless direct current motor torque and suspension force are realized, permanent magnetism material is saved, and a motor weight is reduced.

Description

technical field [0001] The invention relates to a bearingless brushless DC motor, which is a three-phase bearingless brushless DC motor with short-distance windings and Halbach array (radial and tangential mixed arrangement array) permanent magnet rotor structure, which is applied to artificial heart blood Special fields such as pumps, left ventricular assist devices, surgical cutting chainsaws, etc. Background technique [0002] The bearingless brushless DC motor is a new type of motor that integrates the magnetic bearing and the brushless DC motor on the basis of the traditional brushless DC motor structure. It places the suspension force winding directly in the stator slot, so that the suspension force winding and the torque winding share the stator core. At present, the commonly used bearingless brushless DC motors are full-pitch or long-pitch windings. The suspension force winding and torque winding with common teeth are energized at the same time. The magnetic field g...

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Problems solved by technology

[0003] The present invention aims to solve the problems of the existing bearingless brushless DC motors such as complex control, low utilization rate of permanent magnet materials, and small suspension force, and proposes a bearing-less brushless motor with simple control, high utilization rate of permanent magnet materials, and large suspension force. DC motor; Another object of the present invention is to propose a control method of a bearingless brushless DC motor, which can improve the performance of the bearingless brushless DC motor

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