Resolving operational parameters for a change-step type of maglev propulsion system

Abstract

The propulsion principle of the Transrapid maglev train is based on long stator linear synchronous motors. The stator winding in the guideway is divided into multiple segments that are individually switched on or off, with power being supplied to a given segment only as it is passed by the train. In commercial operation the power from substations is connected to the stator segments in one of two ways: change-step connection or three-step connection. Although each type of power supply has its advantages and application scope, the change-step connection is the central topic of interest in this study due to its salient features. When the train's propulsion system uses this supply mode, the inverter control systems at the power stations must know exactly when the stator current begins to decline and the stator segment that it is supplying is about to change. Therefore, the timings to adjust the stator current are crucial to the operating system of a Transrapid train and should be determined from the dynamic conditions of the train. This paper aims to determine the timings for controlling the stator current. Based on calculated results, it is concluded that changing the power supply between stator sections can be smoothly performed using the proposed propulsion control system.