Study on improving EMC of APFC converter with chaotic spread-spectrum technique

For the power tube of APFC converter works in the periodic switching state of high frequency, its rapidly changing voltage and current causes certain electromagnetic interference (EMI). In this paper, a new scheme of APFC converter based on chaotic spread-spectrum technique is proposed, which can make the APFC converter has high power factor and excellent electromagnetic compatibility (EMC). In this paper, firstly the mathematical expressions of the input current spectrum in the standard PWM mode and the chaotic spread-spectrum mode are deduced and simulated, and the input current spectrum of the two modes is compared. It is proved theoretically that the chaotic spread-spectrum technique can improve the EMC of APFC converter. Finally, the circuit simulation is carried out to verify the correctness of theoretical derivation and numerical simulation.