Reserch On The Slip Detecting And Anti-Slip Control Of Electric Locomotive

In recent years, China’s railway is constantly overloading and high-speed, so the locomotives need to get a larger average traction. The traction formation of locomotive depends on the adhesion between wheel and rail. Using the adhesion effectively can increase the average locomotive traction and the use of motor power, on the other hand can improve the safety and comfort of running locomotive. However, the adhesion between wheel and rail is sensitive to environmental conditions and always affected by many factors. Since the randomness of rail surface conditions, the adhesion has a great deal of uncertainty, strong complex time-varying and nonlinear characteristics. A lot of engineering practice and research show that the anti-slip control system can suppress the slip effectively, the effect of the restoration of adhesion between wheel and rail and to reduce power losses is obvious.The key technology of anti-slip is to detect slip and then control it timely. At present, in addition to the measurement of sanding on the surface of rail to improving the contact condition, others to anyi-slip are based on motor controlling. Currently, the identification of slip is mainly based on monitoring the motor shaft or wheel speed and acceleration. Slip occurs when the corresponding value exceeds its threshold, thereby triggering the anti-slip control system to work. As the motor or wheel speed, acceleration has a larger time constant, so that the detecting of slip will be relatively late, resulting in the decrease of locomotive traction and adhesion.In order to study the detecting of slip and anti-slip control of locomotive, build a electric model and its simple kinetic model of a particular clectric locomotive based on MATLAB/Simulink platform. Respectively, do a series of simulation experiments of slip detecting and anti-slip control based on creep speed, acceleration, acceleration derivation, derivation of adhesion coefficient, fuzzy control, load torque and its derivative. Since the reducing of adhesion between wheel and rail when slip occurs, the load torque decreases. Simulation results show that at this time the amplitude of load torque derivation changes greatly. Based on the smaller time constant of electrical quantity, measure the motor voltage and current, and then estimate the load torque of traction motor by using EKF and UKF. According to the changes of load torque and its derivative can detect the slip of locomotive quickly and the simulation results prove it.