Rösel Uta, Kneidl Maximilian, Franke Jörg, Drummer Dietmar
Institute of Polymer Technology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
Institute for factory Automation and Production Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany.
Polymers (Basel). 2023 Feb 25;15(5):1165. doi: 10.3390/polym15051165.
The expanding demand for electro mobility in general and specifically for electrified vehicles requires the expansion of electro mobility technology with respect to variations in the requirements of the process and the application. Within the stator, the electrical insulation system has a high impact on the application properties. So far, limitations, such as the identification of suitable materials for the stator insulation or high costs in the processes, have hindered the implementation of new applications. Therefore, a new technology that allows integrated fabrication via the injection molding of thermosets is founded in order to expand the applications of stators. The possibility of the integrated fabrication of insulation systems to meet the demands of the application can be improved by the processing conditions and the slot design. Within this paper, two epoxy (EP) types with different fillers are investigated to show the impact of the fabrication process in terms of different parameters; these include the holding pressure or the temperature setup, as well as the slot design and with that the flow conditions. To evaluate the improvement in the insulation system of electric drives, a single slot sample, consisting of two parallel copper wires, was used. Then, the two parameters of the average partial discharge (PD) and the partial discharge extinction voltage (PDEV), as well as the full encapsulation detected by microscopy images, were analyzed. It was shown that both characteristics (electric properties-PD and PDEV; full encapsulation) could be improved in terms of an increase in the holding pressure (up to 600 bar) or a reduction in the heating time (around 40 s), as well as the injection speed (down to 15 mm/s). Further, an improvement in the properties can be reached by increasing the space between the wires, as well as the wire and the stack, due to a higher slot depth or by implementing flow-improving grooves that have a positive effect on the flow conditions. With that, the optimization of the integrated fabrication of insulation systems in electric drives via the injection molding of thermosets was enabled with respect to the process conditions and the slot design.
总体而言，对电动出行的需求不断增长，特别是对电动汽车的需求，这就要求根据工艺和应用需求的变化来扩展电动出行技术。在定子内部，电气绝缘系统对应用性能有很大影响。到目前为止，诸如确定适合定子绝缘的材料或工艺成本高昂等限制因素，阻碍了新应用的实施。因此，为了扩展定子的应用，一种允许通过热固性塑料注射成型进行集成制造的新技术应运而生。通过加工条件和槽设计，可以提高绝缘系统集成制造以满足应用需求的可能性。在本文中，研究了两种填充不同填料的环氧树脂（EP）类型，以展示制造工艺在不同参数方面的影响；这些参数包括保压压力或温度设置，以及槽设计和由此产生的流动条件。为了评估电驱动绝缘系统的改进情况，使用了一个由两根平行铜线组成的单槽样品。然后，分析了平均局部放电（PD）和局部放电熄灭电压（PDEV）这两个参数，以及通过显微镜图像检测到的完全封装情况。结果表明，通过提高保压压力（高达600巴）或缩短加热时间（约40秒）以及降低注射速度（低至15毫米/秒），这两个特性（电气性能——PD和PDEV；完全封装）都可以得到改善。此外，由于槽深度增加或通过设置对流动条件有积极影响的流动改善槽，增大导线之间以及导线与叠片之间的间距，可以实现性能的进一步提升。由此，就工艺条件和槽设计而言，通过热固性塑料注射成型实现了电驱动绝缘系统集成制造的优化。
