Based on analysis of the spectrum of constant frequency PWM, periodical frequency-spreading PWM and chaotic frequency-spreading PWM, mechanism and characters of the chaotic PWM of converter for EMI suppressing were discussed.

• 在分析定频、周期扩频和混沌PWM频谱分布基础上,深入探讨了开关变换器混沌PWM抑制EMI的机理和特点。