Verification of Shaft Voltage Reduction Effect Using Layered-Shield in EV Traction Motors

Shaft voltage generated in electric vehicle (EV) motors is a critical issue as it can lead to motor performance degradation and damage, potentially resulting in vehicle fault and endangering the driver’s safety. To prevent such faults, a newly structured layered shield based on flexible printed circuit board (FPCB) has been proposed, and its effectiveness in reducing shaft voltage was experimentally verified when applied to a scaled-down traction motor. This study experimentally investigates the effect of the layered shield on shaft voltage reduction in an interior permanent magnet synchronous motor (IPMSM) type EV traction motor under various operating conditions. The results demonstrate that the application of the layered shield reduced shaft voltage by 80 % in high-voltage systems, significantly enhancing motor durability and preventing faults. This paper presents the effectiveness and applicability of the layered shield in addressing shaft voltage issues in EV traction motors, highlighting its potential to prevent motor faults that are directly related to driver safety.