Effective random space vector modulation for EMI reduction in low-cost PWM inverters

Experimental investigation of electromagnetic interference (EMI) effects in an induction motor drive with a PWM voltage-source inverter is described. A novel, simple version of random pulse width modulation (RPWM) based on the space-vector PWM technique is employed. The switching frequency of the inverter is varied randomly from one switching interval to another, but in contrast to the existing RPWM techniques, only two values of the switching frequency are used. This simplifies the control algorithm and selection of settings of current controller spectra of EMI conducted to mains and of the output voltage are presented and compared with the deterministic and multiple-frequency cases

PWM Inverters - Random Pulse Modulation Quites Motors, Reduces EMI

The paper describes the effect of random PWM on acoustic noise, demonstrating the mitigation effect of spreading the switching harmonics along the frequency axis

Reduction of the Electromagnetic Interference Conducted to Mains in Inverter-Fed AC Drives Using Random Pulse Width Modulation

Results of an experimental investigation of the impact of random pulse width modulation (RPWM) on the electromagnetic interference generated in inverter-fed drive systems are presented. A novel voltage space-vector RPWM technique with a limited pool of switching frequencies was employed. Experiments with an induction motor supplied from a voltage-source inverter, performed in a certified shielded chamber, were focused on the electromagnetic noise conducted to mains. In comparison with the deterministic modulation case, significant reduction of the noise, especially with regard to the quasi-peak values, is shown, demonstrating an important advantage of random modulation