Re-adhesion control for railway traction systems

Slip is a harmful phenomenon in railway. It causes the wear of wheel rail contact surface and mechanical stress of the traction system. Moreover, it may affect the stability of the whole system. The study is concerned with the development of a novel slip detection and re-adhesion control using practical position encoder. In detail, this thesis presents a powered wheelset system driven by an induction motor associated with vector control unit The ~heelset models developed from the study include a comprehensive model which involves longitudinal, lateral and yaw dynamics, a distributed parameter model and a. lumped parameter model with simplified longitudinal dynamics. The dynamics of a wheelset is ~tudied and compared in normal conditions and slip conditions. Simulation results show typical torsional vibration occurs when slip happens. Two possible approaches of slip detection based on the vibration phenomenon are discussed. The first one monitors the torsional torque to detect the slip based on the direct torsional torque measurement In the second approach, a Kalman filter based slip detection method is-presented and evaluated in different operation conditions. Finally a re-adhesion control scheme is developed based on the Kalman filter. The effectiveness of this approach is demonstrated using comprehensive computer simulations.