Nonlinear dynamics of fault electromechanical coupling transmission system in electrical vehicles

To analyze the vibration characteristics of the electromechanical coupling transmission system of electrical vehicles under gear faults, an electromechanical coupling transmission system including two-stage meshing gear and motor system is established. Combining the effects of backlash, transmission error, and time-varying mesh stiffness on the system, the dynamic model of the transmission system includes electromechanical coupling for electrical vehicles is established by using torque as a link between mechanical and electrical systems. The meshing stiffness calculation of different fault extent is introduced to explore the nonlinear vibration characteristics of the transmission system under various faults. The vibration characteristics of systems are analyzed under different rotational speeds, impact loads, and FTP (Federal Test Procedure) actual road conditions. The results show that the cracked gear generates periodic pulses, and its vibration amplitude increases with the extent of crack. Under the same crack extent, the vibration amplitude decreases with the increase of rotational speed and impact load. At the same time, the current receives the same periodic pulse.