Analysis and Compensation of Rotor Position Detection Errors in DC-FRBLM

This paper presents a compensation method to reduce rotor angle detection errors in the DC-FRBLM. The proposed approach involves extracting the fundamental components from the output signals of a magnetic encoder to track the exact rotor angle. By mitigating errors arising from mechanical installation deviations and magnetic field harmonics, the accuracy of detected rotor angle is significantly improved. The impact of estimated angle errors is analyzed in detail, highlighting the need for the compensation method. Experimental validations are conducted to demonstrate the effectiveness of the proposed approach, resulting in enhanced performance of current control. The research contributes to a deeper understanding of rotor angle detection in bearingless motors.

I. Introduction

Bearingless motors have attracted considerable attention owing to their significant advantages, such as absence of lubrication, no direct contact rotor and no pollution [1]–[2]. Among the various types of bearingless motors, the permanent magnet (PM) slice stands out for its simple construction and low drive system requirements [3]. Notably, the flux-reversal bearlingless motor is a variations of the PM slice bearingless motor, offering both simple rotor structure and relatively high torque density. On the basis of the flux-reversal bearlingless motor, the novel DC-FRBLM is proposed in [4]. This motor inherits the advantages of a simple rotor structure and introduces a consequent-pole stator design, which effectively mitigates the risk of demagnetization. Moreover, this design allows for the possibility of rotor suspension using direct current (DC).