The paper presents a locomotive slip phenomena detection method which is based on the Multi-rate Extended Kalman Filter (MREKF) state identification method. The proposed method combines the multi-rate method and the EKF method to identify traction motor load torque in order to detect locomotive slip phenomena.

The proposed detection method is based only on electrical quantities, unlike the traditional method which is based on mechanical quantities. The proposed method achieves a shorter detection time because the time constants of electrical system are much smaller than those of the mechanical system.

The proposed model realizes the simulation of locomotive slip phenomena corresponding to the actual slipping conditions related to wheel–rail condition. The experimental results have verified the accuracy and effectiveness of the proposed model. Comparison between multi-rate and single-rate EKF method provides a comprehensive analysis of the proposed method.