Application of Speed and Load Torque Observers in High-Speed Train Drive for Diagnostic Purposes

In this paper, an application of speed and load torque observers is presented. The aim of the observer implementation is to be used in the diagnostic system for a motor speed sensor and a torque transmission system. The diagnostic system is dedicated to the high-speed train propelled by an induction motor. An analysis of the observed variables allows the identification of problems in the mechanical part of the main traction drive. For example, in the case of speed sensor faults, the motor control system could be switched into speed-sensorless control. The proposed observers were verified by simulation and on a test bench for 1.2-MW rail vehicle motor used in high-speed trains.