Random carrier modulation technique for dispersing harmonics

In many aspects, harmonics will cause a series of problems such as electromagnetic interference (EMI), mechanical vibration and harsh noise. Especially when the amplitude of harmonics is high, more serious problem will arise. For these reasons, this paper has made an analysis of the theory of random carrier modulation and presented a practical random carrier modulation technique which is applied to the pulse-width modulation (PWM). Random carrier modulation (RCM) has unique superiority in expanding the distribution of harmonic spectrum, which is of great value to dispersing of the electromagnetic harmonics and balancing the energy of harmonics in the whole frequency domain. The validity and feasibility of the random carrier modulation are verified by simulations. Besides, the proposed RCM can be easily extended to harmonic treatment in other fields. In short, what has been studied in this paper will greatly contribute to depressing the unanticipated high amplitude harmonics.