Reduction of Audible Switching Acoustic Noise in Motor Drives by a New Two Phase Random Pulse Position PWM Scheme

새로운 2상 랜덤 펄스 위치 PWM기법에 의한 모터 구동 시스템의 가청 스위칭 소음 저감

In this paper, a new two-phase space vector RPWM(Random PWM) is proposed. In the proposed RPWM, each of two-phase PWM pulses is located randomly in each switching interval. Based on the space vector modulation technique, the duty ratio of the pulses is calculated. Along with the randomization of the PWM pulses, we can obtain the effects of spread spectra of inverter output voltage, d.c link current and audible switching acoustic noise as in the case of randomly changed switching frequency. To verify the validity of the proposed two-phase RPWM scheme, the experiment based on the C167 micro-controller was executed. The performance of the proposed scheme was compared with traditional PWM schemes experimentally.