Advanced Pulse Sequence for Saliency-based High-Accurate Rotor Position Estimation of Railway Traction Locomotive Motors

Abstract:
In recent years, railway industry has evinced interest in encoderless traction drive systems, stimulated by the multiple advantages that encoder removal involves. Yet, to achieve sustained zero-speed encoderless control, motor spatial saliencies are required. Particularly, standard railway traction induction motors used in locomotives often exhibit a saliency usually named intermodulation in literature, which allows to track the rotor position with remarkably high accuracy at both low and high loads. This paper presents a method to extract saliencies using advanced pulsing and compares it with the classical INFORM pulse sequence. Experimental validation using a standard 1.6 MW locomotive traction motor is provided.