Aiming at the narrow-band high-frequency harmonic problem generated by the inverter with constant switching frequency

a method based on fuzzy random pulse position modulation（FRPPM） is proposed to reduce the concentrated harmonic cluster in the output voltage spectrum

FRPPM is to spread the original narrow-band harmonics over a wide frequency range to evenly distribute the voltage spectrum in the frequency band

thereby reducing the motor vibration noise generated by the motor air gap magnetic field. The permanent magnet linear motor control system is modeled and simulated by MATLAB/SIMULINK

and compared with the traditional switching mode and analyzed. The results show that the concentrated high-frequency harmonics of the output voltage of the inverter will be effectively reduced at the switching frequency

and the voltage spectrum distribution will be more uniform

thus improving the waveform of the air gap magnetic field of the motor.