Short-Time Transient Thermal Model Identification of Multiple Three-Phase Machines

Short-time thermal transient identification method was successfully adopted to evaluate the slot thermal parameters of induction motors for industry applications. In this work, the modeling approach and the identification methodology are extended to the more sophisticated case of multiple three-phase machines. The generalized model takes into consideration the mutual heat exchange between the windings as well as the possible causes of temperature mismatch. A complete procedure to evaluate the parameters of the modified model is provided, supported by experimental validation on a 7.5 kW machine with two three-phase winding in contact at slot level. The method covers any type of multiple three-phase machines, whatever the thermal promiscuity of the winding sets: from deep coupling as the ones presented, to the case where only the end-turns are in contact, to the completely decoupled case. The proposed technique can be useful for the machine design and for real-time temperature monitoring during operation.