Evolution analysis of wheel polygon wear considering the effect of interharmonics in electrical traction drive system

The formation and development of wheel polygon wear (WPW) present significant challenges to the safety of railway vehicle operations. It is widely accepted that WPW occurs due to the mechanical vibration within the wheel-rail system. The output torque produced by the traction motor acts as the primary power source for the vehicle's movement. The pulsating torque, resulting from interharmonics can directly impact the wheelset's dynamic behavior, contributing to the occurrence of WPW. However, the precise mechanism by which interharmonics affect WPW remains incompletely understood. Therefore, this paper aims to establish the link between interharmonics originating from the electric traction drive system and the wheelset vibration. A comprehensive WPW evolution model that incorporates an electromechanical coupling model and a wheel wear calculation model is developed. This model allows to elucidate the intricate mechanism by which interharmonics impact WPW. The analysis indicates that when the locomotive is running at 70 km/h, the pulsating torque generated by the |5f - 7f0|interharmonic can excite the 1st-order bending mode of the wheelset. This excitation triggers wheelset resonance, which ultimately leads to the development of 20th-order WPW.