Electromagnetic force ripple suppression strategy of the micro permanent magnet linear motor

Abstract

In order to make the micro permanent magnet linear motor in this paper have an excellent position response in MEMS application scenarios, an electromagnetic force ripple suppression strategy based on harmonic current injection is proposed. Because of the simulation phenomenon of large force ripple under standard sinusoidal current driving, combined with the non-sinusoidal distribution model of the air-gap magnetic field, it is theoretically verified that the odd harmonic current injection can effectively suppress the force ripple. The electromagnetic force under the fundamental + 3rd/7th harmonic currents and only the fundamental current is compared by simulation. The force ripple coefficient is reduced from 31% to 1.3%, and the position response speed is increased by about 11% in the 4 mm position closed-loop response simulation. The experimental results show that under a current with 200 Hz frequency, the motor can achieve a displacement of 5 mm within 0.11 s, providing a peak velocity of 40 mm/s, which verifies the correctness of the design concept and control strategy of the micro linear permanent magnet motor.