Improvement of electromagnetic compatibility of motor drives using chaotic PWM

In this paper, a new chaotic pulse width modulation (PWM) scheme is proposed and implemented to reduce the conducted electromagnetic interference (EMI) in motor drives. The key is the use of logistic mapping to chaoize a frequency-modulated signal which then modulates the carrier frequency. Compared with the sinusoidal PWM and random PWM, the proposed scheme not only suppresses the peaky EMI, but also avoids the occurrence of low-order noises and mechanical resonance. Both simulation and experimental results are given to support the validity.