Proposal of Method for Identifying Short-Circuit Fault Points in Concentrated Windings of Motor Stators

Abstract

Short-circuit faults in windings are among the most common faults in motor drive systems and occur when the insulation deteriorates. An easy and effective method for diagnosing such types of faults is urgently required to ensure a highly reliable motor drive system. In particular, a method to identify short-circuit faults can be very useful. There are two techniques used to construct motor windings: concentrated and distributed winding. This paper proposes a method for identifying the fault point at which the short-circuit fault is located in the concentrated winding of a motor. This method involves the measuring of the change in the magnetic field generated by a winding. The difference in the magnetic field before and after the occurrence of a short-circuit fault was theoretically predicted. Further, a numerical analysis was conducted to confirm the predicted change in the magnetic field. In addition, a small magnetic field sensor was developed to measure the magnetic flux density emanating from a winding. Finally, the effectiveness of the proposed method was experimentally verified using the magnetic field sensor.