Patent ID: 11959978
Assignee: NATIONAL UNIVERSITY OF SINGAPORE
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G

Claim 0:
1. A method of detecting a rotor bar fault of an electrical machine, said method comprising,
acquiring a set of online signals from the electrical machine over a period, said set of online signals comprising at least one vibration signal, and a summed signal of magnetic flux signals, each magnetic flux signal obtained from a respective flux sensor positioned on an external surface of the electrical machine,
wherein the summed signal of magnetic flux signals is obtained by acquiring and summing a set of p flux signals to obtain a total flux signal, wherein the set of p flux signals is acquired from p flux sensors positioned along a circumference of a cylindrical frame of the electrical machine, such that any two adjacent flux sensors along the circumference of the cylindrical frame have an angular separation of 360/p degrees with respect to the longitudinal axis of the cylindrical frame, wherein p represents the total number of poles of the electrical machine;
extracting an online anomaly indicator value from the set of online signals;
comparing the online anomaly indicator value with a baseline anomaly indicator value of a corresponding loading condition; and
determining presence of a broken or cracked rotor when the online anomaly indicator value deviates from the baseline anomaly indicator value by a threshold.