公开(公告)号：US10338143B2

公开(公告)日：2019-07-02

申请号：US15653054

申请日：2017-07-18

Applicant: ROLLS-ROYCE plc

Inventor： Chandana J Gajanayake ,  Sivakumar Nadarajan ,  Amit K Gupta ,  Chao Bi ,  Nay Lin Htun Aung ,  Jiang Quan

IPC: G01R31/00 ,  G01R31/34 ,  G01R23/16 ,  G01R33/09 ,  G01R33/12

Abstract: A fault condition is diagnosed in an electric machine that includes a rotor and a plurality of permanent magnets. To do so, the rotor is rotated so that each of the plurality of permanent magnets passes a magnetic flux density sensor, and the values of magnetic flux density are measured using the magnetic flux density sensor at a plurality of positions of the rotor. The measured values of magnetic flux density are analyzed and a magnitude of a peak amplitude is compared in a time or frequency domain with a reference value. If the peak amplitude is below the reference value, the electric machine is determined to have a fault condition.