This paper discusses an unanticipated fault detection,
isolation, and compensation (FDIC) strategy for the arc splicing
permanent magnet synchronous motor (PMSM) operating under a
promising 14.5-meter optical/infrared telescope drive system,
specifically focusing on current sensors. The application is based
on algebraic transformations that allow not only failure detection
but also location and isolation. Besides, detection is performed
merely by means of the measured current sensors and does not require
additional knowledge or estimators; isolation utilizes information
provided by detection to locate where the faults originated and
release isolation signals; and compensation is carried out through
the remaining currents that are not affected by the faults. It is
noted from the results that the performance of FDIC in faulty mode
is very acceptable and uncompromising in terms of fault detection,
current symmetry, speed tracking, load torque and robustness
remedial measures. Therefore, the proposed method can effectively
ensure the stable operation of the drive system in the presence of
faults.