Influence of Thermal Aging on the Winding Thermal Conductivity in Low Voltage Electrical Machines

Abstract

It is widely acknowledged that thermal aging can have a detrimental effect on the reliability and lifetime expectancy of electrical machines. Long exposure times to high temperature can deteriorate the dielectric properties of the electrical insulation system. At the same time, high temperature can strongly affect thermo-physical properties of polymeric materials, which are commonly employed for the insulation system of low voltage motors. This work experimentally investigates what is the effect of thermal aging on the winding equivalent thermal conductivity in low voltage electrical machines. The life results of accelerated thermal aging tests, carried out on suitable specimens, are processed through a Weibull-Bayesian approach. The variation of the equivalent winding thermal conductivity with thermal aging is ultimately correlated to the cumulative thermal aging of the insulation system.

Thermal Modelling of the Cylindrical Electromagnets in Transient and Steady-State Modes

“…In the simple process of electric machines design, the thermal limitations are considered indirectly through a constraint on current density. But in advanced design, the analysis and thermal management are important " (Madonna et al, 2020)". Various tools, both analytical and simulation-based, can be used for the thermal analysis of electric machines.…”