Driver Circuit Design for a New Eddy Current Sensor in Displacement Measurement of Active Magnetic Bearing Systems

Journal article (2022)

Authors

Zhi Cao Southeast University
Yunkai Huang Southeast University
Fei Peng Southeast University
J. Dong DC systems, Energy conversion & Storage - EEMCS
Research Group
DC systems, Energy conversion & Storage (EEMCS) (TU Delft)
Copyright: © 2022 Zhi Cao, Yunkai Huang, Fei Peng, J. Dong
DOI: https://doi.org/10.1109/JSEN.2022.3194567
Active magnetic bearing Position measurement Driver circuit Eddy current sensor
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Published Date

2022

Language

English

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Faculty

Electrical Engineering, Mathematics and Computer Science

Department

Electrical Sustainable Energy

Research Group

DC systems, Energy conversion & Storage

Abstract

Position sensing is one of the crucial parts of the active magnetic bearing (AMB) system. The printed circuit board (PCB) eddy current position sensor is a new type of position sensor for the AMB system, which makes a compact structure, high sensing quality, and is low cost. In this article, an improved driver circuit is proposed for this new sensor. The driver circuit includes an excitation circuit and signal conditioning circuits. A crystal oscillator circuit with a power stage is used to provide the excitation coil with a stable excitation source of high stability and good precision of frequency. The analog demodulation circuit is designed for signal conditioning circuits to extract the rotor displacement information from the sensing coil outputs. Compared with the state-of-art driver schemes, the proposed method reduces the circuit complexity and cost. Accordingly, the experimental results show that the designed sensor has good linearity and sensitivity, and it can ensure AMB stable operation at the rated speed.