Time-frequency and wavelet transforms of EMI dynamic spectrum in chaotic converter

This paper presents a comprehensive analysis of EMI dynamic spectrum of different PWM schemes. Coefficients of wavelet transform of chaotic PWM are less familiar, coefficients of periodic frequency-spreading PWM and stationary frequency PWM are matched for similarities; wavelet reconstruction of different PWM schemes are obtained with high precision; the peak of wavelet power spectrum of chaotic PWM fell off sharply at frequency domain and energy transfer to low frequency stage; Based on time-frequency transforms, renyi information, marginal characteristics and time torque of different PWM schemes are gotten, At last conduct EMI of an adapter was tested under stationary frequency PWM, periodic frequency-spreading PWM and chaotic PWM respectively, experiment results testify the theory analysis.