Conducted EMI reduction in boost converter using dsPIC based chaotic pulse position modulation technique

Abstract

Chaotic PWM control is a new emergent method for suppressing conducted electromagnetic interference (EMI) generated by the dc-dc power converter. It effectively suppresses the peaky harmonics by spreading it all around the central frequency in the desired wide frequency band. Thus the EMI spectrum is smoothed and flattened with a reduced EMI noise level. The current paper presents a chaotic Pulse Position Modulation (PPM) technique based on the Logistic map. It is generated digitally through a dsPIC microcontroller. Then, it is applied to a boost converter to reduce the conducted EMI generated within. Looking for accuracy, an electromagnetic (EM) prototype of the boost converter was developed using LTspice in order to analyse the EMI reduction level. Finally, spectrum simulations were carried out. The chaotic PPM was benchmarked to traditional PWM for the boost converter. Simulations show a significant reduction of EMI with a flattened EMI spectrum.