The intelligent production annular transmission system is composed of straight and arc permanent magnet linear synchronous motors (A-PMLSM). When the mover passes through the A-PMLSM, the thrust ripple will increase due to the increase of the air gap between primary and secondary, which will affect the control accuracy, noise level and operational reliability of the motor. This paper focuses on the research of A-PMLSM of the annular transmission system. The theoretical analysis and finite element simulation methods are employed to clarify the electromagnetic characteristics and output characteristics of four topological structures of the A-PMLSM. The influence of factors such as arc radius and mover width on thrust characteristics are revealed. The methods of parameter and shape optimization are proposed and verified to suppress the thrust ripple.

arc motor， thrust optimization， uneven air gap， arc radius， mover width