Dielectric Characteristics of Electric Vehicle Traction Motor Winding Insulation under Thermal Ageing

The impact of thermal degradation on electrical machine winding insulation

“…We observed previously [27] that the capacitance of the majority of aged insulation samples is lower than 20 pF regardless of the length of ageing time. The only exceptions from this rule were insulation samples aged at 230 °C, where the capacitance drops from 22-24 pF to around 14 pF between 200 and 800 hours of ageing.…”

“…It is observed that during ageing at temperatures lower than or equal to 230 °C, the insulation resistance exhibits a particular trend: it decreases at first, followed by an increase after approximately 400 hours. On the contrary, while ageing at temperatures of 245 °C and higher, the insulation resistance rather increases, which may be an effect of delamination [27]. Furthermore, for almost all aged samples the capacitance of the equivalent circuit model is lower than 20 pF, whilst the average capacitance of new samples is 22 pF.…”

“…unaged) insulation samples was carried out in the same manner. Further details of the experiment design can be found in [27].…”

Investigation of equivalent stator-winding thermal resistance during insulation system ageing

“…The power losses manifest themselves in an elevated temperature, distributed across the machine body. If the losses are inadequately managed, this usually leads to thermal degradation of the machine performance and/or premature failure [2] [3]. In this context, the winding assembly is particularly challenging to design appropriately.…”

The Impact of Thermal Degradation on Properties of Electrical Machine Winding Insulation Material

“…The work presented in this article is a continuation of our research described in [31]. The main contributions of this article are the following: Section III provides estimation accuracy for resistance and capacitance measurements.…”