scholarly journals Conducted EMI of Switching Frequency Modulated Boost Converter

2013 ◽  
Vol 3 (1) ◽  
pp. 12-18 ◽  
Author(s):  
Deniss Stepins
Keyword(s):  
Frequency Modulation ◽  
Experimental Verification ◽  
Electromagnetic Interference ◽  
Modulation Frequency ◽  
Boost Converter ◽  
Switching Frequency ◽  
Research Papers ◽  
Theoretical Results ◽  
Analysis Line ◽  
Conducted Emi

Abstract In this paper conducted electromagnetic interference (EMI) of boost converter with switching frequency modulation (SFM) is theoretically analyzed in details. In the analysis line impedance stabilization network parameters, power inductor and input filtering capacitor parameters are taken into account. The analysis shows that the conducted EMI attenuation due to the use of SFM depends not only on modulation index as it is assumed in numerous research papers, but also on central switching frequency. Useful expressions to numerically calculate SFM boost converter conducted EMI spectrum and attenuation due to the use of triangular and sawtooth modulation waveforms are derived. Additionally experimental verification of the theoretical results is performed using a superheterodyne spectrum analyzer. Moreover a procedure for the choice of optimum SFM parameters (modulation waveform, frequency deviation and modulation frequency) to get maximum conducted EMI attenuation is proposed.

Suppressing Electromagnetic Interference in Switching Converters by Chaotic Duty Modulation

2017 ◽  
Author(s):  
Yuhong Song
Keyword(s):  
Frequency Band ◽  
Frequency Modulation ◽  
Electromagnetic Interference ◽  
Chaotic Signal ◽  
Industrial Applications ◽  
Switching Frequency ◽  
Switching Converters ◽  
Wide Frequency Band ◽  
Switching Converter ◽  
Driving Pulse

The switching converter generates serious electromagnetic interference (EMI), which impairs other devices‘ performance and harms human being’s health. As a way of chaos technique, chaotic modulation has been developed to suppress EMI of the switching converter by dispersing the energy into a wide frequency band and smoothing the peaks of the EMI spectrum. Unlike the well-studied chaotic frequency modulation, the chaotic duty modulation is concerned in this dissertation, which is just to change the duty of the transistor driving-pulse while maintains the fixed switching frequency. Chaotic duty modulation is realized by appending an external chaotic signal to the existing PWM module of the switching converter, which is practicable without the loss of the generality. It is thus verified that this proposal of using chaotic duty modulation in switching converters for EMI suppression is feasible and lays a foundation for industrial applications. ...

scholarly journals Electromagnetic interference of switching mode power regulator with chaotic frequency modulation

2002 ◽  
Vol 15 (1) ◽  
pp. 111-122
Author(s):  
Hei Wong ◽  
Yan Chan ◽  
Sui Wah
Keyword(s):  
Frequency Modulation ◽  
Electromagnetic Interference ◽  
Noise Level ◽  
Pulse Width Modulation ◽  
Chaotic Signal ◽  
Switching Frequency ◽  
Noise Power ◽  
Frequency Range ◽  
Switched Mode Power Supplies ◽  
Switching Mode

In this work, we propose an improved switching scheme (called chaotic frequency modulation (CFM)) for switched-mode power supplies to suppress the electromagnetic interference (EMI) noise source. The basic principle of CFM is to use a chaotic signal to modulate the switching signal so that the harmonics of noise power is distributed evenly over the whole spectrum instead of concentrated at the switching frequency. When compared with the conventional pulse width modulation (PWM) scheme, significant improvements in both conducted and radiated EMI noise levels were found with the proposed CFM method. For conducted EMI, the peak noise level was reduced by 25 dB_V. For radiated EMI, we found that the noise was found mainly in the frequency range of 30 MHz to 230 MHz and the CFM scheme would help to reduce the peak noise level in this frequency range by 22 dB_V.

scholarly journals An Experimental Study of Conducted EMI Mitigation on the LED Driver using Spread Spectrum Technique

2016 ◽  
Vol 62 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Mohammad Yanuar H ◽  
Risanuri Hidayat ◽  
Eka Firmansyah
Keyword(s):  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Power Level ◽  
Luminance Level ◽  
Switching Frequency ◽  
Led Driver ◽  
Design Component ◽  
Component Design ◽  
Current Change ◽  
Conducted Emi

Abstract LED driver has the potential to interfere the system of electronic devices if the voltage and current change rapidly. Several previous studies presented various solutions to overcome this problem such as particular converter design, component design, electromagnetic interference (EMI) filters, and spread-spectrum techniques. Compared to other solutions, the spread-spectrum technique is the most potential way to reduce the EMI in LED applications due to its limited cost-size-weight. In this paper, the effectiveness of conducted EMI suppression performance and the evaluation of its effect on LED luminance using spread-spectrum techniques are investigated. Spread-spectrum is applied to the system by modifying the switching frequency by providing disturbances at pin IADJ. The disorder is given in the form of four signals, namely square, filtered-square, triangular, and sine disturbance signals. The highest level of the EMI suppression of about 31.89% is achieved when the LED driver is given 800 mVpp filtered-square waveform. The highest reduction power level occurs at fundamental frequency reference, when it is given 700 mVpp square disruption signal, is about 81.77% reduction. The LED luminance level will reduce by 85.2% when it is given the four waveforms disruption signals. These reductions occur as the switching frequency of the LED driver does not work on a fixed frequency, but it varies in certain bands. LED brightness level has a tendency to generate a constant value of 235 lux when it is given the disruption signals. This disturbance signal causes the dimming function on the system that does not work properly.

scholarly journals Generation and Mitigation of Conducted Electromagnetic Interference in Power Converters – A Big Picture

2021 ◽  
Author(s):  
Arnold de Beer
Keyword(s):  
Electromagnetic Interference ◽  
Common Ground ◽  
Power Converters ◽  
Direct Consequence ◽  
Boost Converter ◽  
Differential Mode ◽  
Power Filter ◽  
Trade Offs ◽  
Big Picture ◽  
Conducted Emi

This article is a big picture of how electrical noise or conducted Electromagnetic Interference (EMI) is generated and mitigated in power converters. It gives an overview of what EMI in power converters is – from generation through to conduction and mitigation. It is meant to cover the complete subject as a summary so that the reader will have an outline of how to control conducted EMI by design (where possible) and how to mitigate by filtering. A clear distinction is made between Differential Mode (DM) and Common Mode (CM) EMI generation and mitigation. By using a boost converter as an example the trade-offs for DM noise control are discussed. It is shown how CM EMI is generated in a boost converter using the concept of the “Imbalance Difference Model” (IDM). Practical measurements for an in-line power filter is given showing the effect of the filter on the total EMI of a boost converter. Measurements for the CM current produced due to the imbalance difference for different values of the boost conductor are also shown. The main contribution of this study is linking CM noise generation to DM EMI. It is shown that CM noise is a direct consequence of DM noise (although circuit imbalance and coupling to a common ground also play a role). This paper will be useful to designers seeking the “bigger picture” of how EMI is generated in power converters and what can be done to mitigate the noise.

Effects of Switching Frequency Modulation on Input Power Quality of Boost Power Factor Correction Converter

2017 ◽  
Vol 8 (2) ◽  
pp. 882 ◽  
Author(s):  
Deniss Stepins ◽  
Jin Huang
Keyword(s):  
Power Quality ◽  
Power Factor ◽  
Frequency Modulation ◽  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Power Factor Correction ◽  
Harmonic Distortion ◽  
Input Power ◽  
Switching Frequency

Switching frequency modulation (SFM) as spread-spectrum technique has been used for electromagnetic interference reduction in switching power converters. In this paper, a switching-frequency-modulated boost power factor correction (PFC) converter operating in continuous conduction mode is analysed in detail in terms of its input power quality. Initially, the effect of SFM on the input current total harmonic distortion, power factor and low-frequency harmonics of the PFC converter are studied by using computer simulations. Some advices on choosing parameters of SFM are given. Then the theoretical results are verified experimentally. It is shown that, from a power quality point of view, SFM can be harmful (it can significantly worsen the power quality of the PFC converter) or almost harmless. The results depend on how properly the modulation parameters are selected.

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