ARM-Powered Chaotic PWM: A Simplified Solution for EMI Reduction in High-Gain DC-DC Converters

In this paper a simplified Chaotic Pulse Width Modulation (CPWM) method is proposes for minimizing conducted electromagnetic interference (EMI) in high-gain DC-DC converters, address the shortcomings of traditional PWM techniques. In contrast to conventional methods, CPWM uses deterministic chaos to randomize switching pulses, which efficiently distributes spectrum energy and reduces high-frequency harmonic peaks without changing the output voltage and convertor performance. A randomized carrier frequency modulation with a fixed duty ratio (RCFMFD) technique is used for achieving spectral spreading with minimum hardware complexity. The proposed high-gain converter is modelled and simulated in MATLAB/Simulink under periodic and chaotic PWM settings. A hardware prototype is developed with a DC input of 12 V and it was stepped up to a 200 V DC at a 200 kHz switching frequency with a 35% duty cycle. An ARM based processor generates both conventional and CPWM switching pulses, interfaced to the MOSFET gate through a driver. A power spectral density (PSD) comparison reveals that CPWM achieves a maximum conducted EMI suppression of about 23.08 dB<inline-formula> <tex-math notation="LaTeX">$\mu \text {V}$ </tex-math></inline-formula> (equivalent to <inline-formula> <tex-math notation="LaTeX">$22.6~\mu \text {V}$ </tex-math></inline-formula>) compared to conventional PWM. The results verify that CPWM offers a compact, cost-effective, and high-performance EMI suppression solution suitable for EMI-sensitive applications such as electric vehicles, aerospace, and medical electronics.