[Objective] Canned permanent magnet synchronous motor(CPMSM) is widely used in high-demand industrial fields due to its excellent safety and tightness

and is mostly powered by frequency converter. However

the time harmonic current generated by the frequency converter will lead to electromagnetic disturbance inside the generator

change the coupling characteristics of multi-physical fields

and cause forced deformation of the shielding can. Long-term operation may lead to structural fatigue and even motor damage. Therefore

in-depth study of the influence of harmonic current on the electromagnetic force per unit length distribution and structural response of the can is of great significance for revealing the deformation mechanism

optimizing the motor design and improving the operational reliability. [Methods] In this paper

a 1.5 kW

9 000 r/min CPMSM was taken as the object to carry out the joint simulation of electromagnetic field and structural field. Firstly

based on the electromagnetic field theory

the analytical formula of radial electromagnetic force considering time harmonic current was derived. Then

the simulation model of CPMSM was constructed. By applying harmonic currents with different parameters

the electromagnetic force per unit length on the inner side of the can was calculated

and the forced deformation response of the can of three stainless steel materials of SUS304

SUS316

SUS430 was analyzed. [Results] The simulation results showed that the electromagnetic force per unit length increases with the increase of the amplitude of the time harmonic current

and the frequency of the electromagnetic force increases with the increase of the number of time harmonic current

but the amplitude was basically unchanged. There was a cosine relationship between the electromagnetic force per unit length and the phase angle

which has obvious modulation characteristics. Among them

SUS430 material had the largest electromagnetic force per unit length and deformation under the same excitation due to its high permeability. [Conclusion] This study reveals the influence of time harmonic current on the electromagnetic force per unit length distribution of the motor and the forced deformation of the can. It provides a theoretical basis for motor structure optimization and harmonic suppression. It is of engineering significance to improve the operation stability

and also provides a reference for the design and material selection of the can.