Conducted Noise Spectrum Research Articles

Effect of diode operating temperature on conducted-noise spectrum for CCM DC–DC boost converter

Effect of diode operating temperature on conducted-noise spectrum for CCM DC–DC boost converter

Analysis of conducted EMI with standalone solar powered dc motor

The green environment warrants not only researchers, but rather all citizens, to adopt renewable energy sources. One such option is the use of solar energy, especially the conversion of light energy from the sun to electric energy. The conversion of light to electricity with the help of photovoltaic cells (PV), though widely used, has its own problems, such as undesirable electromagnetic interference (EMI), both in radiation and conduction modes. The present research aims to mitigate the unwanted EMI in the conduction mode (to limit the scope of the research). The mitigation of the conducted EMI on a DC/DC buck converter was studied with a standalone 4050 W PV plant. The conducted EMI was measured and the effectiveness of randomization on the spreading of the dominating frequency was examined by a simulation using PSpice software, and the same was validated in real-time measurements. All of the investigations were accomplished using an embedded LPC2129 ARM processor. The theoretical analysis and the experiment results of the conducted noise spectrum were compatible with each other, based on which a randomized duty ratio and a random pulse-position modulation (RPPM) with a fixed carrier frequency scheme were contemplated for adoption.

FPGA-Based Spread-Spectrum Schemes for Conducted-Noise Mitigation in DC–DC Power Converters: Design, Implementation, and Experimental Investigation

This paper proposes a family of spread-spectrum schemes, several of which are new, for conducted-noise reduction in dc-dc converters. The schemes use three randomized parameters to generate the switching signals: carrier frequency, duty ratio, and pulse position. The increasing performance and cost reduction of field-programmable gate array (FPGA) technology have made the application of these schemes possible in this field. A theoretical framework for a general representative scheme is provided. Then, the proposed schemes are designed and implemented using an FPGA-based controller. Furthermore, the effect of using the proposed controller on common-mode, differential-mode, and total conducted-noise characteristics of the dc-dc converter is experimentally investigated. In addition, the three randomization parameters are swept to determine the values that best achieve the conducted-noise spectrum spread. All studied cases are designed, implemented, and experimentally investigated. Then, the conducted-noise spectra are compared. The experimental results show that the use of the proposed controller with the determined randomization values significantly improves the conducted-noise spectrum and effectively reduces the noise peaks at both high- and low-frequency ranges.

Power electronic converter EMC analysis through state variable approach techniques

A technique based on the state vector approach and a simple switch device model is proposed for electromagnetic compatibility (EMC) analysis in converter design. The conducted noise spectrum is straightforward computed in the frequency domain for hard switching converters with alternating or direct current input sources. The results are compared with PSpice time-domain simulations mixed with the fast Fourier transform, considering a buck converter. The technique proposed in this paper is appropriate for applications where calculation speed is preferred rather than high precision.