Simulation Research On Adhesion Control And Dynamics Of Locomotive Under Traction

Railway heavy haul transport has always bean an important direction of development. The locomotive power is enhanced unceasingly. These put forward the harsh demands of locomotive adhesion utilization. For that reason, adhesion control devices have been widely applied to the locomotives of most countries. While there will be complex dynamics problems when locomotive under high adhesion utilization. Moreover, the problem of wheel-rail wear is becoming increasingly serious. The research on dynamics of locomotive under saturated adhesion, applying adhesion control, and reasonable matching suspension parameters to get high adhesive performance has a strong engineering application value. Furthermore, the simulation research by combining multibody dynamics and modern control theory is one of the main development directions of locomotive adhesion control technology. The main work in this paper is as follows:(1) The electromechanical control integrated simulation platform is established. Consist of train system dynamics model, electric drive and control system, and adhesion control system. Including locomotive dynamics model with detailed drive system, series excited DC motor speed control system, AC induction motor vector control system, adhesion control system by hybrid control method and a method based on optimal creep rate. Using the revised Shen’s non-linear theory, wheel-rail adhesion curves of different rail surface conditions can be obtained by changing the coefficient of static friction.(2) The stick-slip vibration of locomotive on straight line and curve are simulated. And the influence of suspension parameters is analyzed. When stick-slip vibration happens, there are wheel-set longitudinal vibration and motor pitch vibration, and furthermore there are wheel-set yaw and lateral vibration on curve. Appropriate increase the suspension stiffness is conducive to the stability of the drive system.(3) Two kinds of adhesion control method are compared. The influence of suspension parameters on locomotive adhesive performance and the dynamics performance of locomotive under saturated adhesion are analyzed. The results show that suspension stiffness can not be too small, and suitable suspension stiffness will reduce the wheel-rail wear. The lateral ride quality is improved under adhesion control. The outside wheel-rail vertical force, wheel unload ratio and wheel yaw angle are increased. The lateral forces between wheel and rail are decreased on small radius curve, but increased on big radius curve. The wear is increased both on straight line and curve, moreover the wear of the outside of wheel-set1,4are the most serious, and the smaller the radius the more serious the wear.(4) The influence of traction torque and adhesion control on the steering characteristics and wheel-rail wear, and the influence of primary suspension parameters are researched. The locomotive’s steering ability on small radius curve is already poor, and the influence of traction torque is little. While the traction torque makes the steering ability worse and the wheel-rail wear increase obviously on big radius curve. The smaller the radius, the longitudinal creep component and the traction ability is smaller. Increasing the primary lateral stiffness and decreasing the primary longitudinal stiffness may reduce wheel-rail wear.