Investigation of an Analytical Method for the Dynamical Thermal Behavior of Electrical Machines

This paper presents the analysis of an analytical method for the thermal calculation of electrical machines. The goal is to apply a method which is based on an analytical first order low pass approximation to two different permanent magnet synchronous machines. Therefore, the machines are represented by an LPTN with six nodes. The resulting temperatures of the machines during rated operation and during a driving cycle are evaluated. The results of the analytical solution are compared with conventional LPTN and FEA. For both, conventional and analytical LPTN, identical stationary temperatures can be determined. However, during transient operation, a difference between both calculation methods can be detected. Calculating driving cycles, a higher deviation for periods with higher power losses can be observed. Thus, the presented method shows an accuracy within an acceptable range, depending on the dynamical behavior of the respected driving cycle.