Improvement of Frequency Characteristic of Self-Sensing Active Magnetic Bearing with Zero-Bias Current Control

Abstract

An improvement of frequency characteristic of self-sensing active magnetic bearings (AMBs) with zero-bias current control is proposed. In the self-sensing AMBs non-liner magnetic characteristic of electromagnet degrades the frequency characteristic of the position sensing. Furthermore noise is observed due to alternations of electromagnet's excitation. This also degrades the frequency characteristic. In this paper, current-interference compensation and linearizing current disturbance are utilized. The method achieves improvement of the frequency characteristic of the position sensing.