Propulsion control for controlled-PM LSM levitation system with gap-length fluctuation

Controlled-PM linear synchronous motor (LSM) is a potential structure type for levitation system. Although the levitation and propulsion is controlled independently, they may influence each other. The change of gap-length may worsen the propulsion performance and the d-axis current may aggravate the levitation load. This paper presents a decoupled control for thrust and lift force, and a vehicle-loaded magnet flux oriented control of propulsion considering the gap-length change. The numerical simulation and experiments for propulsion and levitation control shows satisfactory performance for a controlled-PM LSM model vehicle in our Lab.