Abstract: Taking the permanent magnetic synchronous linear motor as the research object, its force was analyzed; mathematical model was established, and the simulation model of the linear motor by using Matlab/Simulink in order to study the thrust and speed change of the linear motor when different loads are applied. The results show that with the increase of the workpiece’s mass, the state response time and maximum deviation of the linear motor increased; the response time curve of the speed is flat; the response time curve of thrust changed obviously; the overshoot curve of thrust increase flatly; the overshoot curve of velocity increased stably, the overshoot curve of speed is obvious.When the quality of the workpiece is 240 kg, the over-adjusting amount of motor speed exceeds 30%, which seriously affects the operation of the motor. In order to reduce the effect of load change on linear motor stability, the maximum load quality and maximum motor thrust are calculated.

Key words: linear motor, variable load, Simulink, modeling simulation