VP10-07 Exploring the Application of High Conductivity Graphene-copper Composites for High Speed Motors
Creators: Jiaqiang Li，ruilin Pei
Li yangyang
yuejun An
Publisher: name: IEEE
Year: 2025

In recent years, the booming electric vehicle market has put forward higher requirements for the efficiency and temperature rise of drive motors. Flat wire motors have significant advantages in efficiency, power density, heat dissipation, etc., but its larger conductor cross-section is accompanied by the skin effect, high-frequency operating conditions of AC loss is twice as much as DC, inhibiting the development of flat wire motors to high-speed[1-3]. How to inhibit high-frequency AC copper loss to ensure motor efficiency and thermal safety has become an urgent problem. In this paper, a high conductivity graphene-copper composite material is proposed as a motor winding to reduce AC copper loss in high-speed motors, and its applicability and reliability are demonstrated. In this case, the graphene-copper composite material is shown in Fig. 1. On the basis of material preparation, the mechanical properties and electrical conductivity of the material are explored for different tension conditions and frequency conditions. Copper graphene is found to have good electrical conductivity and is suitable as a motor winding material. Based on the reference motor topology with 48 slots and 8 poles, the ordinary copper material and graphene-copper composite material are used as the motor windings, and the copper loss of the motor is calculated to compare and analyze the changes of the AC loss and efficiency under different working conditions, and to analyze the suppression of the skin effect of graphene-copper composite material under high frequency, The current density distribution of the graphene-copper composite material is shown in Fig. 2. It is found that the conductivity of graphene copper composite material is 18.6% higher than that of ordinary copper material under 1000Hz condition, and the AC copper loss is reduced by 40% under the condition of maximal torque.References: [1] M. Aoyama and J. Deng, "Visualization and quantitative evaluation of eddy current loss in bar-wound type permanent magnet synchronous motor for mild-hybrid vehicles," in CES Transactions on Electrical Machines and Systems, Vol. 3, pp. 269-278(2019) [2] C. Du-Bar and O. Wallmark, "Eddy Current Losses in a Hairpin Winding for an Automotive Application," 2018 XIII International Conference on Electrical Machines (ICEM), Alexandroupoli, Greece, pp. 710-716(2018). [3] G. Berardi and N. Bianchi, "Design Guideline of an AC Hairpin Winding," 2018 XIII International Conference on Electrical Machines (ICEM), Alexandroupoli, Greece, pp. 2444-2450(2018).
In recent years, the booming electric vehicle market has put forward higher requirements for the efficiency and temperature rise of drive motors. Flat wire motors have significant advantages in efficiency, power density, heat dissipation, etc., but its larger conductor cross-section is accompanied by the skin effect, high-frequency operating conditions of AC loss is twice as much as DC, inhibiting the development of flat wire motors to high-speed[1-3]. How to inhibit high-frequency AC copper loss to ensure motor efficiency and thermal safety has become an urgent problem. In this paper, a high conductivity graphene-copper composite material is proposed as a motor winding to reduce AC copper loss in high-speed motors, and its applicability and reliability are demonstrated. In this case, the graphene-copper composite material is shown in Fig. 1. On the basis of material preparation, the mechanical properties and electrical conductivity of the material are explored for different tension conditions and frequency conditions. Copper graphene is found to have good electrical conductivity and is suitable as a motor winding material. Based on the reference motor topology with 48 slots and 8 poles, the ordinary copper material and graphene-copper composite material are used as the motor windings, and the copper loss of the motor is calculated to compare and analyze the changes of the AC loss and efficiency under different working conditions, and to analyze the suppression of the skin effect of graphene-copper composite material under high frequency, The current density distribution of the graphene-copper composite material is shown in Fig. 2. It is found that the conductivity of graphene copper composite material is 18.6% higher than that of ordinary copper material under 1000Hz condition, and the AC copper loss is reduced by 40% under the condition of maximal torque.References: [1] M. Aoyama and J. Deng, "Visualization and quantitative evaluation of eddy current loss in bar-wound type permanent magnet synchronous motor for mild-hybrid vehicles," in CES Transactions on Electrical Machines and Systems, Vol. 3, pp. 269-278(2019) [2] C. Du-Bar and O. Wallmark, "Eddy Current Losses in a Hairpin Winding for an Automotive Application," 2018 XIII International Conference on Electrical Machines (ICEM), Alexandroupoli, Greece, pp. 710-716(2018). [3] G. Berardi and N. Bianchi, "Design Guideline of an AC Hairpin Winding," 2018 XIII International Conference on Electrical Machines (ICEM), Alexandroupoli, Greece, pp. 2444-2450(2018).