Optimizing Operation of Segmented Stator Linear Synchronous Motors

Linear synchronous motors present both advantages and challenges when used to control vehicles on a guideway. It is often advantageous to split a stator into small segments and drive each segment independently, but this strategy introduces complications not found in single stator systems. Distinctions include stator back-electromotive force variation with vehicle position, vehicle thrust constant variation due to gaps between the stators, and the requirement to synchronize stators overlapped by a common field array. Strategies for compensating for these characteristics are presented, as implemented in both the low-level inverter current control loop and the high-level vehicle motion control loop. This paper also describes a method of optimizing the efficiency of segmented stator installations and an analysis of the appropriate stator segment length for an urban maglev application.