Anti-Slip Re-Adhesion Control Strategy of Electric Locomotive Based on Distributed MPC

Abstract

In order to ensure the stability and safety of the train during operation and the traction of electric locomotive, this paper proposes an electric locomotive anti-slip re-adhesion control method based on distributed model predictive control (distributed MPC). The method uses the wheel-rail adhesion zone as the time domain constraint of the distributed MPC to avoid the wheel-rail contact state into the sliding zone. In addition, the output torque of the traction motor is limited by the maximum torque of the motor which varies with the angular velocity and voltage of the motor. Therefore, the maximum output torque limit of the traction motor is regarded as the time-varying constraint of the system. Control objectives include: safety and stability of train operation, good traction and braking performance, and avoiding wheel orbit wear caused by idling or sliding of the wheels. Using distributed MPC constraint control, the locomotive is stable and safely operated by constraining the wheel-rail adhesion zone. In addition, slack variable constraints have been added to ensure the feasibility of state constraints. Finally, the joint simulation experiment is carried out on the semi-physical simulation platform to verify the effectiveness of the proposed control method.