Flux Weakening Surface Mounted Permanent Magnet Servo Motor Design with Enhanced Self-Sensing Properties

Abstract

Servo motors are widely used in automation and robots. These motors achieve high dynamic performance with precise motion control. Flux weakening surface mounted permanent magnet synchronous motors (FW-SPMSMs) are the main type used in servos due to high peak torque allowing high acceleration rates, and low cogging and ripple torques allowing smooth and precise motion control. Standard FW-SPMSMs are not suitable for injection-based self-sensing control. Many techniques have been reported in the literature to design slightly salient SPMSMs. However, the reported techniques are not suitable for servo applications due to the loss of motor saliency with load or the techniques might affect the motor power conversion through degrading the peak, cogging, or ripple torques. This paper will present a new methodology for the design of high-performance FW-SPMSMs for servo applications with enhanced self-sensing properties without degrading motor power conversion. The designed motor saliency improves with load leading to enhancement of self-sensing performance.