Application of speed and load torque observers in high speed train

This paper presents a solution for observer based diagnostic system in high speed train with induction motor. The concept of the diagnostic system is dedicated to the mechanical part of the drive. The system is monitoring both motor speed sensor and torque transmission system. In case of speed sensor fault the control system could be switched into sensorless mode. Monitoring of torque transmission system allows to limit the motor torque in case of serious problem and gives an information to maintenance center for testing the suspected gear. The proposed system was verified by simulation and in test bench for 1.2 MW rail induction motor.