An improved passivity‐based control for suppressing the traction motor torque ripples due to traction network voltage fluctuation in high‐speed railways

Abstract

AbstractWhen the voltage fluctuation of the traction network occurs in high‐speed railways, the interharmonics in the grid‐side voltage will propagate to the traction motor, which results in the motor torque ripple of running trains. The ripple can cause abnormal vibrations of key train components and even influence train operation safety. However, the traditional proportional‐integral controller used in the inverter‐motor system has a weak anti‐interference capability when facing nonlinear disturbances. This paper proposes an improved passivity‐based control (IPBC) to suppress the impact of interharmonics on trains. First, the Euler‐Lagrange mathematical model of the traction inverter‐motor system is established. Then, the PBC for this system is designed by damping injection, ensuring the asymptotic stability of the system. Furthermore, to purposely suppress the impact of the periodic disturbance on the system, a repetitive controller is designed in parallel with the PBC to control the inverter‐motor system. Finally, through the offline simulation and HIL simulation, it has been verified that the proposed IPBC can effectively suppress the motor torque ripple and the vibrations of key train components. The control strategy proposed in this paper has a reference significance for improving the operational stability of high‐speed trains.