Design of Line-Start Permanent Magnet Linear Synchronous Motors With Transient Optimisation

Abstract

This paper proposes an optimisation theory to enhance the transient performance of the line-start permanent magnet linear synchronous motor (line-start PMLSM). Constraints are constructed first by addressing the design of the line-start PMLSM. Then a multi-objective description is established to unify the transient responses, including the damping response and the time response, in the line-start process and the transient optimisation strategy is established via particle swarm optimisation (PSO). With different combinations of weighting functions in the multi-objective expression, optimisation cases are analysed and the optimised design of the line-start PMLSM prototype are experimentally tested. The proposed theory is proved to be a feasible and efficient design method of the line-start PMLSM. Three optimal principles of the line-start mover topology are addressed, in which the damping response is addressed to have more impact on the optimal design of the line-start PMLSM compared to the time response. Meanwhile, a larger number of conductive rungs are proved to enhance the performance during the online starting phase. Trends of the combination between permanent magnets and conductive materials are also derived to optimise the damping response and the time results. These optimal principles can be another contribution for the industrial PMLSMs requiring online-starting capability.