Triple-Hybrid Switching Strategy for Conducted-Noise Level Reduction in DC-DC Converters

A novel switching strategy for conducted-noise level reduction has been proposed in this paper. The proposed strategy uses three randomized parameters for generating the switching signals. These parameters are carrier frequency, duty-ratio, and the pulse position. This triple-hybrid switching strategy has been designed and implemented using field-programmable gate array (FPGA) technology. Moreover, the effect of using the proposed controller on commonmode and differential-mode noise, total conducted-noise, and radiated-noise characteristics of the dc-dc converter has been experimentally investigated. Furthermore, sweeping of the three randomization parameters has been carried-out for identifying the values which achieve the best conducted-noise level reduction. Numerous cases have been studied. All the studied cases have been designed, implemented and experimentally investigated. Then, the conducted-noise spectra have been compared. The experimental results show that using the proposed technique, with the identified randomization parameter values, significantly improves the conducted-noise spectrum and effectively reduces the noise peaks in both high- and low-frequency ranges. Moreover, the radiated-noise spectrum has been improved.