A Comparative Study of Carrier-Frequency Modulation Techniqu(6)

Abstract—A rigorous mathematical analysis and a comparative study of carrier-frequency modulation (CFM) techniques for the conducted electromagnetic interference (EMI) suppression in pulsewidth-modulated converters is presented. CFM techniques dither the

TSEetal.:CARRIER-FREQUENCYMODULATIONTECHNIQUES

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(a)

(b)

(c)

Fig.6.Theoreticalpowerspectraoftheinputcurrentwith1f =16

.

=6kHzand =2.(b)f

=750Hzand

).

Increasingcaneffectively

dispersethelow-orderharmonics.However,withthe

sameand

different

Fig.7.Modelofthetriangle-likefilterresponseintheEMCanalyzer.

smaller

.Themeasuredspectrumisunabletodif-ferentiatetheeffectiveness

of

issufficientlylarge,thePSDofthemeasuredPWM

waveformisuniformlydistributed.Themeasuredspectrumwill

increases.increase

as