CONTROLLED INDUCTION MOTOR DRIVE IN RAILWAY TRACTION

Abstract

This habilitation thesis presents improvements in selected areas of induction motor drive application in railway traction vehicles. One of the most common induction motor control strategies in railway traction drives, is the Rotor Flux-Oriented Control. To reach high performance and high efficiency of the drive, precise knowledge of the induction motor equivalent circuit parameters is needed. Inaccurate knowledge of the induction motor equivalent circuit parameters leads to FOC detuning, which causes misalignment of the estimated flux position and, thus, inaccuracy of the whole control part. The problematics of induction motor drive parameter identification and accuracy of the induction motor model is one of the key points of the thesis. The other part of the thesis describes a slip controller's development for freight locomotive with the induction motor drive, that is based on adhesion-slip characteristic slope detection. The proposed slip controller is designed to cope with a nonlinearity of the adhesion-slip characteristic and noise that occurs in the system. Moreover, the proposed slip controller does not need to know the train velocity, the wheelset velocity is only required parameter. The slip controller is designed as modular, and it consists of the adhesion-slip characteristic slope detection part and a controller part with acceleration protection.