Thermal Analysis of Squirrel Cage Induction Motor Under Fault Operating Conditions

Authors

  • G.Sakthivel, D.Prince Winston

Abstract

This paper proposes a thermal model for a Squirrel Cage induction motor for fault tolerance applications. Three and single-phase squirrel cage induction motor fed drives are widely used in industries for lot of applications. Because of versatility and roughness squirrel cage Induction motors (I.M) are the work horse in an industry. Broken rotor faults, faults associated with stator, damage in motor shaft and bearing fault leads to unplanned down time associated with cost and safety factors. During condition monitoring and fault diagnosis, Rotor faults and bearing faults are frequently encountered whereas stator and in shaft are less frequent in an Induction motors. Based on stator current analysis detection of fault in a machine is challenging now a days, if the rotor cage suffers multiple breakage at non adjacent position. Electromagnetic asymmetries due to adjacent damaged rotor bar, shaft and bearing mask the diagnostic ability of the fault. Thermal analysis and electromagnetic analysis using Finite Element Analysis (FEA) is simulated and analytical methods are also carried out in an IM of 70W, 230V, 0.34A to find out the hottest element in an Induction motor under standstill condition. Depending on fault severity in the motor rotor bar and end rings of an induction motor gets heated much. Because of this increase in temperature the rotor bar losses and stator copper losses which depend on stator current also increases. By decreasing the stator frequency or by increasing the torque the stator current is increased which results increase in heating of all the elements. Even though induction motor has certain limitations but exceeding the limit may result in premature failure of the stator winding and rotor bars.

Keywords-Induction motor,Finite element analysis,Thermal analysis

Published

2020-12-24

Issue

Section

Articles