Non-Linear Mathematic Model of a Segmented Powered Permanent Magnet Linear Synchronous Machine

Due to the segmented arrangement of windings in long primary dual-three phase permanent magnet linear synchronous machine (PMLSM), the adjacent segments will cause the off-set pulsating magnetic field, and the mover passing through the powered segment will also cause complex transient processes. In this paper, in order to describe the dynamic characteristics of the PMLSM precisely, a phase-domain mathematic model is established and the two fore-mentioned special effects are considered. The causes of off-set pulsation in the air-gap flux distribution are analyzed by the analytical method, and the unbalanced inductance and saturation effects caused by the off-set flux distribution are studied. A 2-D inductance look-up table in αβ coordinate system is established to reduce the computation consumption of the model. Then, the easy-to-derivative Sigmoid function is introduced to describe the no load flux linkage and back electromagnetic force. Finally, the mathematic model is established, the voltage and thrust are calculated by the model and verified by the finite element method. Finally, an experiment platform based on the RT-Lab is built. The results show that the model can reflect the various effects of the motor and can replace the finite element model with a large computational cost. © 2021, Electrical Technology Press Co. Ltd. All right reserved.