Thermal monitoring of the stator winding insulating part by a reliable thermal model for failure mitigation

Abstract

Electrical motors fed by a voltage inverter always supply voltages in non-sinusoidal waveforms such that the current flowing through the machine is rich in harmonics. This not only increases losses in the machine but also leads to more severe thermal stress which affects the stator winding. Therefore, accurate and continuous monitoring of the coil temperature with reliable thermal models is essential, improving, the reliability of the motors. This paper focuses on the thermal reliability model study of a stator winding of Three Star Induction Machine TSIM shifted by 30° and fed by a nine leg voltage source inverter (VSI). A new application of the diffusive approach on the TSIM thermal reliability solution is also investigated. Moreover, the nodal method based on the thermal equivalent circuit is examined. The reliability, as well as the effectiveness of the proposed diffusive approach, are validated by experimental results. These results, together with the obtained simulations, show clearly the validity and the great reliability of the proposed diffusive approach.