I- Introduction

II- Finite Elements Model

III- Simulation Results

IV- Conclusions

References

Abstract

As the main workforce of the global industry, it is fundamental to clearly understand all failures modes that may potentially deteriorate induction motors. Condition monitoring methodologies based on the thermal analysis of induction motors have tremendous potential as a health monitoring tool of any electric motor technology. In addition to the intrinsic benefits related to a non-invasive diagnostic technique, thermal analysis provides suitable information for the early detection of a plethora of fault scenarios. One of the fault modes which remains fairly unexploited in the literature is the short-circuit fault between turns of the stator windings. To assess the effects of such faults in the temperature of the stator windings of an induction motor, this paper develops a thermal model of the induction motor under study, resorting to the Finite Elements Method (FEM). To develop the FEM model, the simulation tool Flux2D (Cedrat) is employed. Distinctive fault severity levels are considered through the variation of the short-circuit resistance.

INTRODUCTION

Electric motors develop an important role in an endless number of industry applications. It is estimated that 44 % to 46 % of the electric energy consumed worldwide is used by electric motor drives [1]. Within the aforementioned group, industry is the most representative activity sector. Nearly 64 % of the electricity consumption in industry is related to electric motor drives [1]. Stator failures are among the most common fault phenomena occurring in induction machines. For low voltage machines, stator faults account for about 9 % of the total number of failures; in medium voltage machines this value rises to 35/40 %, while in high voltage machines this value reaches up to 65 % [2]. Of particular interest is the analysis of the temperature distribution inside the motor. High operating temperatures and abnormally hot spots strongly affect the machine performance and its reliability. In general, the windings’ insulation is the element of the induction motor showing the lowest capability to withstand extremely high temperatures.