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.