A Novel Parallel-Connected Multiple Induction Motors Vector Control Method for the Rolling Stock Traction System

Abstract

In the field of the rolling stock traction system, one inverter often drives multiple induction motors connected in parallel, because of its compactness, lightness and economical advantages. A high performance three level invereter system using high voltage and large current IGBTs that can drive multiple induction motors has been widely adopted. On the other hand, in order to provide passengers of comfortable ride feeling and to keep the train schedule even in rainy days, an accurate and responsive motor torque control is demanded. Considering this situation, we have already developed a stator-flux-oriented vector control method for the rolling stock traction system in which one inverter feeds multiple induction motors. Here, we have newly developed a novel vector control method which can improve the stability of the traction system and the motor torque response. We have also evaluated the proposed control method through stability analysis, simulations and experiments. This paper presents the principle of this control method and the mechanical and electrical models of the rolling stock traction system, as well as stability analysis, simulation and experimental results.