Dynamic modelling of locomotive with direct drive traction system considering electromechanical coupling effect

AbstractPermanent magnet synchronous motors (PMSMs) have been employed in the direct drive traction system of locomotives as the traction motor. Due to the unique traction structure of the direct drive system, complicated excitations such as track irregularity and harmonic torque have a direct effect on the dynamic performance of the motor and other key components of the locomotive. However, the dynamic characteristics under this effect and influencing law have not been revealed completely. This paper develops a dynamics model of a locomotive with direct drive traction system which enables considering the electromechanical coupling effect between the vehicle subsystem and the PMSM control subsystem. The nonlinearity of the wheel–rail contact and flexible transmission coupling are taken into account in this model. By using this model, the dynamic responses of the locomotive are analysed under electrical and mechanical excitations. The results indicate that the harmonic components in the electrical subsystem have considerable effects on the key components of the locomotive, such as the wheelsets and the motors. It can also cause resonance in the mechanical transmission system when the locomotive is operating at a specific speed. This resonance can be eliminated by adopting the harmonic suppression algorithm.KEYWORDS: Direct drive traction systemlocomotive dynamics modelelectromechanical couplingpermanent magnet synchronous motorharmonic torque Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by National Natural Science Foundation of China [grant numbers 52022083, 52275132, 51735012].