Improving the Water Jacket Cooling for Flywheel Energy Storage Systems: An Investigation on the Potting and Polyamide-imide/Boron Insulators

High torque density requirement in the permanent magnet (PM) motors is accompanied by severe heat generation in the thermally sensitive elements, such as the armature windings and PMs, and the resultant hot spots are detectable during the thermal investigation, threatening the stable motor operation. In this study, a new generation of insulating materials is employed to alleviate the hotspots and achieve a 3-D uniform temperature distribution without increasing the workload of the water cooling jacket cooling unit in an Internal PM motor. Advanced materials with a diverse thermal conductivity range are studied, and their impact on the thermal resistance of the end spaces and slots is investigated analytically. Subsequently, numerical models are utilized to calculate the temperature distribution, proving the advanced materials’ positive effect on the 3-D temperature uniformity and the temperature mitigation of the hotspots and stator side. Moreover, it has been confirmed that although the energy consumption and power rating of the centrifugal pump in the cooling strategy with the advanced materials is in a much better situation compared to the strategy without them, the implementation cost is much higher, which stems from the high cost of the advanced materials and affects their popularity.