A mechatronic approach for effective wheel slip control in railway traction

Abstract
This article proposes a radically new approach for the detection of wheel slip/slide and re-adhesion control of AC traction motors in railway applications, which provides an important alternative and advantageous technique in traction/braking control systems to maximize the use of adhesion in poor contact conditions. The proposed concept explores the variations in the wheelset dynamic properties caused by the condition changes at the wheel—rail contact, and detects and controls the slip conditions from the dynamic behaviour of a wheelset, indirectly. All the dynamic motions of rail wheelset, which are closely related to wheel—rail contact mechanics, are included in the study; the influence of contact conditions on the relevant modes is assessed, which is essential in the development of a mechatronic solution based on dynamic interactions. This is different from the more general approaches in many other studies on traction controls where the inclusion of only wheelset rotation and longitudinal motions are considered as sufficient. The development of the slip detection and re-adhesion control schemes is presented and comprehensive simulation results are produced to support the proposed idea.