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

2003 ◽  
Author(s):  
H. Wong ◽  
Y. Chan ◽  
S.W. Ma
Keyword(s):  
Frequency Modulation ◽  
Electromagnetic Interference ◽  
Power Regulator ◽  
Switching Mode

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.

Suppressing Electromagnetic Interference in Switching-Mode Power Supplies by Chaotic Carrier Frequency Modulation

2017 ◽  
Author(s):  
Junying Niu
Keyword(s):  
Frequency Modulation ◽  
Carrier Frequency ◽  
Electromagnetic Interference ◽  
Power Supplies ◽  
Main Concern ◽  
Practical Consideration ◽  
Practical Applications ◽  
Chaotic Signals ◽  
Switching Mode ◽  
Chaotic Carrier

Due to the unpredictable and random-like features of chaotic signals, chaotic carrier frequency modulation (CCFM) technique, by which the spectra of input and output signals can be spread over a wide frequency band without changing the total energy, has been used to suppress electromagnetic interference (EMI) of switching mode power supply (SMPS). So far, the study on CCFM was focused on theoretical analyses, simulations, and experimental verifications, lacking of a practical consideration of applying CCFM in real power supplies, which will be main concern of this dissertation. To provide efficient and economical EMI suppression solutions, a CCFM module is proposed to serve as a plug-in component for power supplies with standard PWM ICs, and for designing a chaotic frequency PWM IC, it is necessary to integrate a chaotic frequency oscillator into the standard PWM IC, which is to be realized both in analogue and digital manners for various practical applications. ...

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. ...

Spread Spectrum Microwave Power Generation for Improving Efficiency

1996 ◽  
Vol 430 ◽  
Author(s):  
W. M. Van Loock
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Frequency Modulation ◽  
Power Supply ◽  
Microwave Power ◽  
Spread Spectrum ◽  
Electromagnetic Interference ◽  
Frequency Bands ◽  
Ism Band ◽  
Microwave Generators

AbstractMicrowave power for heating applications is normally generated in the designated ISM frequency bands which occupy a band of 4%. Actual microwave generators, such as are used in domestic ovens utilise only a small fraction of this bandwidth. It is being demonstrated that spreading the power uniformly over the full ISM band by controlled frequency modulation dramatically reduces all levels of potential electromagnetic interference. With such controlled modulation telecommunication channels can operate within the ISM bands without serious problems because the leakage levels are reduced by 20 to 30 dB with no additional shielding costs. One simple (though not optimum) modulating waveform is a large ripple voltage on the magnetron power supply. Frequency modulation that spreads the energy over the full ISM band also improves the overall energy efficiency in multimode heating applications.

scholarly journals Suppressing Conducted DM EMI in an Active Power Filter via Periodic Carrier Frequency Modulation

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1903 ◽  
Author(s):  
Shengbao Yu ◽  
Nan Chen ◽  
Lihui Gao ◽  
Haigen Zhou ◽  
Yong Huang
Keyword(s):  
Power Systems ◽  
Frequency Modulation ◽  
Carrier Frequency ◽  
Electromagnetic Interference ◽  
Double Fourier Series ◽  
Active Power ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Nonlinear Load ◽  
Suppression Effect

Active power filters (APF) aim at solving the harmonic problem originated by the nonlinear load in power systems. However, the high dv/dt and di/dt outputs from power electronic devices in a voltage source converter on APF introduced unwanted conducted electromagnetic interference (EMI) when compensating for the low-frequency harmonic components. Hence, this paper develops a spectrum analysis approach to investigate and quantify the source differential-mode (DM) voltage of a single-phase shunt APF to suppress the DM EMI via periodic carrier frequency modulation (PCFM). In this scheme, the analytical expressions of source DM voltage in the APF using the PCFM scheme are obtained with a double Fourier series. In addition, the influence of PCFM parameters on the source DM voltage spectrum is predicted based on the analytical expression. As a result, the PCFM parameters, which have the best suppression effect on the DM EMI are obtained. The experiment results proved the validity of the sawtooth PCFM APF with the maximum frequency deviation equal to 800 Hz in alleviating the APF DM EMI.

scholarly journals Novel Technologies for Design and Analysis of Switching Mode Power-Supply Circuit Based on Solitary Electromagnetic Wave Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-15
Author(s):  
Hirokazu Tohya ◽  
Noritaka Toya
Keyword(s):  
Electromagnetic Wave ◽  
Power Supply ◽  
Electromagnetic Interference ◽  
Buck Converter ◽  
The Novel ◽  
Supply Circuit ◽  
Novel Technologies ◽  
Power Supply Circuit ◽  
Switching Mode Power Supply ◽  
Switching Mode

The novel solitary electromagnetic wave (SEMW) theory and the novel design methodologies of the switching mode power supply circuit (SMPC) are presented. The SEMW theory was developed as a basic theory of the design of all kinds of the switching mode circuit including SMPC by fusing the physics of semiconductor, nonlinear undulation, and electromagnetic wave. When the SEMW theory is used, the electromagnetic analysis of SMPC becomes possible by using only the real parameters based on the physics. The technologies of the low impedance lossy line (LILL) which is used to the DC line and the matched impedance lossy line (MILL) which is used to the switching line are also presented. They are effective for suppressing the electromagnetic interference. SMPC can be reconfigured to the quasistationary state closed circuit (QSCC) by applying LILL and MILL in accordance with the SEMW theory. No electromagnetic interference exist in QSCC. The buck converter which is one of the most popular DC-DC converters is presented as an example of the method for being reconfigured to QSCC. The conventional design tools which includes SPICE based on the AC circuit theory will be effective for the design and analysis of the inside circuit of QSCC.

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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