Identification of short-circuit location in induction motors using radiated electromagnetic field signatures

Finding the location of partial short-circuit in electrical machines enables the operator to fix specific winding segments before it expands into a larger fault causing major down time. This paper investigates the identification process for locating this type of fault in the windings of a machine through radiated electromagnetic field signatures. It is proposed to recognize short-circuit types such as inter-turn, inter-coil or terminal-turn faults. The location of short-circuit can be identified through the frequency response of the radiated magnetic field of the machine. The responses were compared based on the variations of the amplitudes of the harmonic and inter-harmonic orders. To use this method for various practical situations, two different approaches were used for locating the short-circuit conditions in an optimal manner. The experimental study of short-circuit; especially the major and semi-major cases, could damage the winding. Instead, the full three-dimensional finite element (3DFE) method was utilized in few cases and verified experimentally. Finding the locations of small short-circuit assist engineers in fixing the specific winding fault before a major damage occurs.