In order to quickly evaluate the torque characteristics of surface mounted permanent magnet vernier motors

this paper constructs an accurate electromagnetic analytical model. Firstly

the spatial permeance distribution of the air gap is analyzed based on conformal mapping

and the magnetic field harmonic model is established based on the theory of magnetic field modulation to reveal the distribution law of spatial magnetic field harmonic and permeance. Then

this paper establishes an analytical model of electromagnetic torque including spatial distribution modulation effect to quantitatively characterize the spatial coupling characteristics of harmonic components of magnetic permeance and electromagnetic torque. Furthermore

the space attenuation characteristic of the air gap magnetic field caused by the slot effect is analyzed by using the air gap stratification method

and the characteristic is introduced into the torque analytical model. The results show that compared with the traditional analytical method

the calculation error can be reduced by considering the spatial attenuation characteristics

and the calculation efficiency of the analytical method is increased by 89%. The proposed model lays a foundation for evaluating the torque characteristics of permanent magnet vernier motors quickly and accurately.