Дисертації з теми "Conducted and radiated EMI"
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Seddighi, Mohsen. "Study, measurement, and modeling of the propagation of conducted emissions due to on-board chargers in grids with various earthing systems." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPAST087.
Повний текст джерелаThe transition to electric vehicles (EVs), driven by policies to decarbonize transport and significant technological advances in electrical energy storage and conversion, will continue over the coming decades. What's more, future on-board chargers (OBCs) with bidirectional power supply will contribute to greater grid stability, peak-shaving, and even improved integration of renewable energy resources: we're talking about the "vehicle-to-grid" (V2G) concept. This means that not only will the number of EVs increase, but also their charging and discharging times when connected to the grid.The need for compact equipment, favored by the availability of high-speed switching components (SiC GaN), has prompted manufacturers to increase the operating frequencies of OBCs (> 50-100 kHz), with the corollary of increasing their conducted and radiated electromagnetic emissions. As a result, these noise sources remain connected to the grid and operate for extended periods, making it necessary to anticipate potential Electromagnetic Compatibility (EMC) problems in energy networks: this is the general aim of this work.One of the subjects of this thesis concerns the standardized method of measuring conduct-ed emissions, in which the noise measurement impedance via the Line Impedance Stabilization Network (LISN) is not always representative of the impedance of the LV network, nor of course of its possible fluctuations. Thus, different grounding systems provide paths with different HF impedances, which can alter the level of emissions. Consequently, the discrepancy between the normative configuration with LISN and the actual impedance at the point of access to the power network can impact the effectiveness of EMC filtering, leading to potential malfunctions in neighboring systems and/or those connected to the same network.The need to analyze impedance variations and their consequences on EMC filters led us to develop and implement a methodology for measuring the RF impedance of the noise termination while operating at nominal mains voltage and in the absence of the LISN. This approach makes it possible to measure the line impedance of various equipment and power supplies, in particular, the distribution network. Based on these observations, the study of the impact of actual network impedance on the optimized volume of an EMC filter was approached through scenarios where different normative levels were considered.In order to examine the conducted emissions caused by our prototype bidirectional on-board charger in a controlled environment without LISN, a microgrid connected to the real net-work via an isolation transformer was built. This enabled us to control its parameters: source impedance, cable length, grounding system and to control impedance variations due to locally connected loads. Conducted emissions were then measured and analyzed at various points on the microgrid, according to different configurations (grounding regime and different loads on the microgrid).In parallel, a frequency model of the microgrid was established using a new approach based on the use of a SPICE-type solver and the experimental acquisition of elementary impedances, enabling faster simulation for large systems. This work was followed by rigorous verification procedures to ensure model accuracy and fidelity. A "black box" behavioral model has been developed for the OBC, defining the noise source and its impedances. This makes it possible to simulate parasitic current levels at any point in the microgrid, whatever the connected loads.As a result, the model of the entire system has enabled us to analyze impedance variations and conducted emissions in an extended version of the realized system. The thesis will present a synthesis of the results
Wang, Zijian. "Conducted EMI Noise Prediction and Filter Design Optimization." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/73166.
Повний текст джерелаPh. D.
Liu, Qian. "Modular Approach for Characterizing and Modeling Conducted EMI Emissions in Power Converters." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/29633.
Повний текст джерелаPh. D.
Avola, Alessia. "Analysis and Reduction of Conducted EMI in Power Electronic Modules." Doctoral thesis, Università di Catania, 2015. http://hdl.handle.net/10761/3748.
Повний текст джерелаMurase, John Takeshi. "Investigation of Buck Converter Radiated Emissions (150 kHz - 30 MHz) Measured according to CISPR 25." Thesis, KTH, Elektroteknisk teori och konstruktion, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-140954.
Повний текст джерелаFreeman, Larry. "PREDICTION AND MEASUREMENT OF RADIATED EMISSIONS BASED ON EMPIRICAL TIME DOMAIN CONDUCTED MEASUREMENTS." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4232.
Повний текст джерелаM.S.E.E.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering
Bishnoi, Hemant. "Behavioral EMI-Models of Switched Power Converters." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/23936.
Повний текст джерелаPh. D.
Midya, Surajit. "Conducted and Radiated Electromagnetic Interference in Modern Electrified Railways with Emphasis on Pantograph Arcing." Doctoral thesis, Stockholm : Skolan för elektro- och systemteknik, Kungliga Tekniska högskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10574.
Повний текст джерелаDolente, Andrea <1976>. "Analysis of the heatsink influence on conducted and radiated electromagnetic interference in power electronic converters." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/410/1/TesiDott.AndreaDolente.pdf.
Повний текст джерелаDolente, Andrea <1976>. "Analysis of the heatsink influence on conducted and radiated electromagnetic interference in power electronic converters." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2007. http://amsdottorato.unibo.it/410/.
Повний текст джерелаMrad, Roberto. "Conducted EMC modeling and EMI filter design integrated class-D amplifiers and power converters." Thesis, Ecully, Ecole centrale de Lyon, 2014. http://www.theses.fr/2014ECDL0019/document.
Повний текст джерелаSwitching power management circuits are widely used in battery powered embedded applications in order to increase their autonomy. In particular, for audio applications, Class-D amplifiers are a widespread industrial solution. These, have a similar architecture of a buck converter but having the audio signal as reference. The switching nature of these devices allows us to increase significantly the power efficiency compared to linear audio amplifiers without reducing the audio quality. However, because of the switching behavior, Class-D amplifiers have high levels of electromagnetic (EM) emissions which can disturb the surrounding electronics or might not comply with electromagnetic compatibility (EMC) standards. To overcome this problem much architecture appeared in the state of the art that reduces the emissions, however, this has never been enough to remove electromagnetic interference (EMI) filters. It is then useful to optimize these filters, thus, it has been set as the goal of this PhD thesis. The latter has been divided to four main axes which can be resumed by the following. First, this work started by developing a frequency domain modeling method in order to simulate and predict the EMI of Class-D amplifiers in the final application. The method is based on system to block decomposition and impedance matrix modeling and manipulation. After providing all the theoretical background, the method has been validated on integrated differential Class-D amplifier. The experimental measurements have permitted to validate the method only up to 100MHz. However, this is sufficient to cover the conducted EMC frequency band. Second, the EMI at the supply rails of Class-D amplifiers has been treated. As the battery is often the same power supply for all applications in an embedded system, an EMI filter or a decoupling capacitor is needed to prevent the noise coupling by common impedance. Designing this filter needs the knowledge of the battery impedance at the desired frequencies. Therefore the present work dealt also with measuring the high frequency impedance of a battery. Afterwards, an experimental validation has been carried on with a DC-DC converter and a Class-D amplifier. The developed model allows a virtual test of the switching device in the final application. However, it is more useful if the model is able to help the system integrator in designing filters. Thus, third, the model has been implemented in an optimization loop based on a genetic algorithm in order to optimize the filter response, and also, reduce the additional power losses introduced by an EMI filter. The optimization search space has been limited to the components available on the market and the optimization result is given as component references of the optimal filter referring to the optimal solution found. This procedure has been validated experimentally. Finally, EMI filters often are constituted by magnetic components such as ferrite beads or inductors with magnetic cores. Thus, introducing the EMI filter in the audio path, adds a nonlinear behavior in the audio frequency band. Designing a high quality EMI filter require taking into account this phenomenon and studying its impact of the original amplifier audio performance. Therefore, the Jiles-Atherton model for magnetic materials has been used for ferrite bead modeling. Hereafter, the impact on the time and frequency domain signals has been simulated and compared to measurements. Finally, the total harmonic distortion (THD) has been computed for different signal amplitudes and compared to the THD measured using an audio analyzer. Accurate results have been obtained on a wide range of signal amplitudes. As a conclusion, this work aimed to design optimal EMI filters for Class-D amplifiers. Thus, we dealt with improving their EMI response, reducing their additional power losses and evaluating their impact on the audio quality
Oswald, Niall Fraser. "Towards an improved trade-off between switching losses and radiated EMI generation in hard-switched power converters." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627948.
Повний текст джерелаYang, Liyu. "Modeling and Characterization of a PFC Converter in the Medium and High Frequency Ranges for Predicting the Conducted EMI." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/35226.
Повний текст джерелаMaster of Science
Siraj, Ahmed Shahnewaz. "Impact of Repetitive Short Circuit Transients on the Conducted Electromagnetic Interference of SiC and Si Based Power Devices." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1622056294414037.
Повний текст джерелаLévy, Pierre-Etienne. "Modélisation du rayonnement électromagnétique quasi-statique des composants magnétiques de puissance - Application à la compatibilité EM -." Thesis, Cachan, Ecole normale supérieure, 2015. http://www.theses.fr/2015DENS0019/document.
Повний текст джерелаThe number of electronic devices in embedded systems is constantly increasing and their contribution to volume and weight is a major concern. In order to solve these issues, a large research effort is devoted to volume reduction and power converters' integration. This lead to constant technological evolution including the appearance of high frequency power electronic converters allowing the reduction of the volume of passive components.However, due to the increase of operating frequencies and the minimization of inter-components distances, the electromagnetic radiations generated by these systems become more important. In order to decrease this interference, EMI filters are often necessary. Their performances are often related to the value of parasitic elements in the filter which must therefore be controlled. Nonetheless most of the existing models focus on conducted electromagnetic interference (EMI) and the impact of radiated phenomena is often ignored or greatly simplified. This work will therefore focus on developing highly accurate radiation models for magnetic components commonly used in EMI filters using both numeric and analytic tools.First, the magnetic fields radiated by differential mode (MD) toroidal coils, which belong to the basic magnetic components, will be thoroughly studied. This study highlighted the critical parameters determining the near-field topology. The main result is the discovery of the impact of the winding's layout around the magnetic core on the radiated magnetic field. New models have been developed in order to predict the radiated near field.Then, an accurate analytic model of the the magnetic radiation of common-mode (CM) chokes has been developed. It allows the prediction of the magnetic near-field. The application of the model lead to the correlation between radiated phenomena and conducted effects existing in these components. The importance of the winding on CM to DM mode coupling has therefore been highlighted.Finally, the electromagnetic (EM) susceptibility of these components has been studied. This work describes the influence of an external magnetic field on the components and validates the radiation models developed using the principle of EM reciprocity. It has been shown that the easy directions are the same for both the radiated and the coupled phenomena
Wang, Shuo. "Characterization and Cancellation of High-Frequency Parasitics for EMI Filters and Noise Separators in Power Electronics Applications." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/27885.
Повний текст джерелаPh. D.
Saber, Christelle. "Analysis and optimization of the conducted emissions of an on- board charger for electric vehicles." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLN034/document.
Повний текст джерелаBattery chargers for electric vehicles are classified as on-board or off-board chargers. Off-board chargers are not constrained by size or weight but introduce additional cost to the infrastructure through the deployment of a high number of charging stations. In order to meet the needs of electric vehicle users in terms of charging availability, on-board chargers that achieve ac/dc conversion are retained. Furthermore, on-board chargers are classified as standalone or integrated systems. By reusing parts of the traction power train for charging, the latter reduces the cost of the charger. Disadvantages of integrated systems include electromagnetic compatibility issues and complex control schemes.This work presents the power quality performance analysis and control optimization of an on-board non-galvanically isolated electric vehicle charger integrated to the traction’s power train. In order to be able to evaluate the high frequency conducted common mode emissions (150 kHz - 30MHz) of a power conversion structure, one needs to develop a good current control scheme that establishes a high-quality low frequency behavior (0 - 2 kHz). Therefore, different aspects related to the power factor correction of the single-phase as well as the three-phase charging configurations are studied: the control scheme for the regulation of the charging power, the displacement power factor correction, the suppression of the grid current harmonics and the active damping of the input filter’s resonance. Two experimental test benches are developed using two different technologies (Silicon IGBTs vs. Silicon Carbide Mosfets). Experimental results are provided.This work also presents a comprehensive approach to modeling the CM and the DM EMI behavior of a power electronics structure. This method is applied to the charger in its single-phase and three-phase configurations. The models allow to evaluate the fluctuating internal nodes and to study the effect of various proposed mitigation solutions on the CM emissions. The models are also developed in the intent of being injected into optimization algorithms for the future design of an optimal EMI filter
Douzi, Chawki. "Effet du vieillissement par fatigue électrothermique sur la compatibilité électromagnétique des composants de puissance à base de SiC." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMR002/document.
Повний текст джерелаThis research work focuses on the electrothermal aging effect on the electromagnetic compatibility of power components based on silicon carbide SiC. It focuses on two major parts ; an experimental part and another more oriented modelization. Experimentally, this thesis studies the aging effect of SiC transistors used in static converters on the electromagnetic interferences EMI generated by these converters. The second part deals with the modeling of these transistors in order to emulate the effect of their aging on the EMI of the modules they compose. This step made it possible to validate the methodology developed for the simulation of the conducted EMI of a healthy SiC MOFSET at first and of an aged SiC MOSFET in a second time. Overall, this innovative modeling approach developed in this work helps the designers of static converters to predict the conducted EMI before and after aging without going through the measurement. This provides additional information on the evolution of the EMC signatures of such modules during its lifetime and thus to estimate the risk associated with the aging of the components
Demus, Justin Cole. "Prognostic Health Management Systems for More Electric Aircraft Applications." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1631047006902809.
Повний текст джерелаLidstedt, Joakim. "Evaluating Compromising Emanations in Touchscreens." Thesis, Linköpings universitet, Informationskodning, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-157366.
Повний текст джерелаNayak, Bibhu Prasad. "Hybrid Electromagnetic Solvers for EMIEMC." Thesis, 2021. https://etd.iisc.ac.in/handle/2005/5591.
Повний текст джерелаLai, Chih-Chung, and 賴志忠. "Adjustable Conducted EMI Filter Design." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/j9fv2f.
Повний текст джерела國立臺北科技大學
電機工程系所
100
The rapid evolution of electronic science and technology innovation yields small and light goods with large capacity and high speed. The small size limits the design space, leading to increasingly serious EMI (electromagnetic interference) problems. EMI is mainly divided into radiation type and conductivity type. Conducted EMI noise passes through the power lines. Hence, EMI in the same power system circuit will interfere with each other through the power lines. Generally, the solution of conducted EMI is to add an LC filter at the supply side entrance. Then, the EMI can be prevented to outflow. In order to solve EMI problem, engineers need to rent expensive equipment, certificated venue and booking measurement time slots. They often take only several normalized inductances and capacitors to go to a lab for testing. If engineers can not figure out the solution of the EMI noise after the testing, they need to prepare other inductances and capacitors next time. This thesis proposes an adjustable conducted EMI filter. The common-mode inductance can be on-line and continuously adjusted. Hence we can find the corresponding ideal filter frequency very soon. With this design, engineers do not to need to spend so much time to go back and forth to the laboratory to do circuit modification. By doing this, EMI issues can be fixed more efficiently.
Sung, Tzu-Heng, and 宋自恒. "Software-Based Conducted EMI Noise Measurement System." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/06969288057743719844.
Повний текст джерела國立臺灣科技大學
電子工程系
88
For most electronic engieers, it is a hard work to conquer the EMI problem and yet no systematic method can be followed. In this thesis, we will derive an algorithm to estimate the magnitude spectrum of CM (Common mode) or DM (Differential mode) noise. Also, a suitable EMI filter model will be selected and a program with a friendly user interface to fulfill the functions of the software-based EMI measurement system is developed in Visual Basic. The features of this system include noise measurement, variant EMI filter design, design of the damping circuit for the EMI filter, the estimation of CM/DM noise spectrum, and linear-scaled axis/log-scaled axis transformation, etc. With the proposed system, any user can easily select the functions by clicking on the buttons of items shown on the PC monitor. Therefore, one can quickly obtain the optimum filter configuration and find a simple and effective way to design EMI filter.
Lin, Guo-Hua, and 林國華. "Simulation of Conducted EMI in Two-Stage Converters." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/23909520568919750730.
Повний текст джерела國立臺灣科技大學
電機工程系
93
The purpose of this thesis is to investigate conducted electromagnetic interference issues in two-stage converters. The pre-stage is for power factor correction from AC voltage to DC voltage and the structure is the circuit of conventional bridge rectification with a boost converter added. The post-stage circuit is functioned to transform from DC voltage to the rated DC voltage of load with the structure of flyback converter. According to electromagnetic interference regulations, the problematic electromagnetic interference may delay products reaching the market. If the electromagnetic interference problem analysis and improvement can be controlled before the circuits are done, it will definitely avoid unnecessary re-design or modifying circuits. Cost and time efficiency can both be improved. To reach this goal, this research proposes a systematic analysis and simulation method. At the beginning design stage of switching mode power supplies, conducted electromagnetic interference frequency band leveled at 150kHz~30MHz is considered. According to the actual high-frequency characteristics for each component within the said frequency band, the high-frequency models for active components, passive components and the printed circuit board are established separately. The models are then combined with the line impedance stabilization network model, to accomplish the conducted electromagnetic interference simulation for the circuit system of two-stage converters. Finally, simulated and measured EMI noises are compared. Thus, the problematic electromagnetic interference can be predicted. This is very helpful to save time and cost caused by electromagnetic interference problems.
Shieh, Li-Chi, and 謝浬奇. "Numerical Analysis of EV ASD system conducted EMI." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/87480221397082247235.
Повний текст джерела國立臺灣大學
機械工程學研究所
98
Adjustable Speed Drive (ASD) system is essential in a variety of electric vehicles. It is different from the traditional gasoline engine vehicles. ASD system is an extra interference of the electric vehicles and the degree of disturbance is also greater than other electronic components. Therefore, it is an important issue to find out how ASD system conducts the intensity of EMI in 150k-30MHz through data simulation at design stage. In this research, ansoft simplrer system-level circuit software is used for simulating the intensity of EMI by conducting of NTU Green Jumper’s ASD system, which also includes IGBT device dynamic model, IPM motor high frequency model, snubber circuit, power line and bus parastic parameter with coupling. Based on the simulation result, ASD system can successfully conduct EMI in 150k-30MHz and the error could be less than 10dB, which confirmed that EMI modeling method can be accurately used at the design stage, and also be the reference for a filter designing. In experimental operation, I made the test in S1 wave isolation room at Automotive Research & Testing Center and obtained frequency domain data after checking background’s interference can meet test requirements.
Wang, Ting-Kuo, and 王定國. "Analysis of Conducted Emission EMI and Filter Design." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/06855673740475214434.
Повний текст джерела清雲科技大學
電機工程研究所
97
Ever since the initial development in 1970’s, the switching mode power supplies have been widely adopted in various electronic apparatus, such as personal computers, laptop computers, printers, digital cameras , mobile phones, … etc. Switching power supplies become essential for modern human life. From the power supply technical point of view, there are several remarkable progresses in the past decades, such as high-efficiency topologies, high performance power semiconductors, various integrated control circuits, and low-loss magnetics, which make the power supply more efficient and reliable. However, accompanying with the technologies of high density PCB layout and high-frequency switching, the noise coupling problem between the PCB wirings and the components are getting more and more serious. The so-called “Electromagnetic Interference” (EMI) has always bothered the power supply engineers. In terms of noise generation and noise coupling, many uncertainties exist inside the power supply system. Most engineers can resolve the EMI issues only by try and error method. In this thesis, an analytic approach to identify the noise amount of an active power factor corrector is proposed, which is great helpful for designing the noise filter. Besides, a common/differential noise separator is adopted to distinguish the noise types, which can be used for efficient filter design. Measurement to identify parasitic parameters of filter components are also included, which illustrates the noise spectrum in different frequency range. Finally a systematic approach is proposed to design a suitable noise filter. Implementation of the noise filter in a 300W hardware is presented to verify the feasibility of the theoretical derivation.
Kong, Shi-Qi, and 孔詩琦. "Conducted EMI Filter Design of Three-phase Converters." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/fk2962.
Повний текст джерела許智堯. "Analysis and Improvement of Print Circuit Board Layout for Radiated EMI." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/39910652438865192839.
Повний текст джерела明新科技大學
電機工程研究所
98
With the developments in high-tech field, the problems of electromagnetic interference are also increasing. When the device becomes faster speed and higher density, the noise is also greater. The electromagnetic noise is likely to make itself broken or the functional output abnormal. The electromagnetic interference can affect environmental equipments by means of transmission medium. Electromagnetic noise can be divided into conducted emission and radiated emission. In this thesis, we study radiated emission by using EMIStream software, and we carve these print circuit boards (PCB) by using PCB prototype machine. With suitable PCB layout, the radiated emission will be reduced.
Li, Kuan-Ying, and 李冠穎. "Design and Implementation of Conducted EMI Filter for PV Inverter." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/51708796096169035302.
Повний текст джерела中原大學
電機工程研究所
101
To reduce the power density of the power supply, the switching frequency of switching power supply (SPS) is getting high, but also causes the increasing of electromagnetic interference (EMI). This thesis is to develop the EMI filters between the input and output of the PV inverter so as to suppress EMI noise complying with CISPR22 (Comité International Spécial des Perturbations Radioélectriques) ClassB suppression standards. In this study, differential-mode and common-mode separation techniques for suppressing EMI at input and output of the PV inverter are investigated. Three kinds of filter ladders of 1 to 3 are examined with analysis and simulation. Finally, a demonstrated prototype of 500W PV inverter with two-ladder filter at input and three-ladder filter at output is explored to verify the attenuation capability and noise suppression effect. The experimental results are close to the theoretical evaluation and comply with CISPR22 Class B.
Chen, Chih-Shan, and 陳志善. "Phase Shift Controlled Dual-Transformer Flyback Converter for Mitigation of Conducted EMI." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/65862385617562128003.
Повний текст джерела輔仁大學
電子工程學系
95
Abstract The mobile power supply devices were usually lower than 100W in the past . Due to most electronic product functions increase today ,the power requirement is more and more and reach 220W(max) . Both high power and shrinkage space make the 220W power supply design challenge. Therefore, dual-transformers flyback circuit is generally used in the high power supplying product. That can make the space application more efficient and heat dissipated more effectively then reduce the height of the power supply. This paper provide a shift phase method to drive dual-transformer’s MOSFET for improve the loop current which caused by dual-transformer and reduce the EMI interfere/output capacitor. Then we can reduce the EMI component and output capacitors. So total price can be reduced about 1~2 USD and reduce the design cycle time, Also achieve the main goal of reduce product price, size and weight….etc . Both simulating and experimental results are given in detail. Keywords: Conducted EMI, Flyback converter, Shift phase control, Push-pull control.
Cheng, Chung-Yu, and 鄭仲佑. "Study on the Modified EMI Filter for Suppressing Narrow-band Conducted Noise." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/89947329624426003160.
Повний текст джерела國立成功大學
電機工程學系碩博士班
97
This thesis proposes the modified EMI filter for suppressing narrow-band conducted noise. The circuit consists of sorts of passive elements, including the induction winding, capacitors and resistors. By combining the passive elements in series and parallel to produce resonance, the modified EMI filter is made to achieve the narrow-band conducted noise suppression. By designing and adjusting ideal parameters of elements to produce resonance, it achieves to reduce common-mode noise current and differential-mode noise current efficiently of the narrow-band conducted suppression without affecting broad-band conducted noise suppression. This paper further provides to prove the modified EMI filter for suppression of narrow-band conducted noise, which can effectively reduce electromagnetic interference from the narrow-band conducted noise by theoretical analysis added with circuit simulations and results of measured experiments.
謝月女. "Conducted common-mode noise suppression for switched power supplies with active EMI filter." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/91878268962638528611.
Повний текст джерелаShih, Chou Kuo, and 郭世州. "Determining the Optimal Parameters for Conducted EMI Filters Using Multi-Objective Genetic Algorithms." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/56166145821630670017.
Повний текст джерелаPei-Hsin, Liu. "Simulation and Analysis of Conducted EMI for a Commercial High-density DC/DC Power Module." 2005. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-1407200522452100.
Повний текст джерелаLiu, Pei-Hsin, and 劉沛鑫. "Simulation and Analysis of Conducted EMI for a Commercial High-density DC/DC Power Module." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/18786299910481111715.
Повний текст джерела國立臺灣大學
電機工程學研究所
93
Electromagnetic Interference (EMI) has always been a major concern for power electronic circuit design engineers. Despite the progress made in recent years, there is still “black magic” associate with fixing the EMI problems in the industry. Attempts have been made in the past few years to use simulation tools to predict conducted EMI behavior in power electronic circuits and results were reported in research articles. However, the results reported in these articles were obtained in research environment. Doubts were expressed if such results can still be meaningful in a commercial environment. To address such an issue, efforts were spent to investigate the conducted EMI of a commercial 40-Watt 320-KHz 15-volt output high-density DC/DC power module using computer simulation tools. In the thesis, methodology of computer simulation of EMI behavior is outlined. Parasitic elements of importance, including those of the power components, the printed circuit board, and the assembly package, were included in the simulation. IsSPICE was used for time-domain simulation and Fast-Fourier Transform function was used to converter the simulation results into frequency-domain EMI data. It is concluded from the investigation that simulation complexity can be reduced to a practical level without losing the accuracy for frequency range below 10MHz. Although the accuracy is limited, analysis of the results already provides useful information and practical guidance for EMI reduction for the product. For frequency beyond 10MHz, the simulation results deviate significantly from the experimental results. This is not unexpected. Package proximity effects, which are still not fully understood, were not incorporated in the simulation. Further works along this line is needed in the future.
Du, Hong-bin, and 杜弘彬. "Confirmation of the High Frequency Model for Conducted EMI in Passive Components ─ Simulation and Measurements." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/88848474019545321219.
Повний текст джерела國立臺灣科技大學
電機工程系
97
The purpose of this thesis is to investigate the generalization of the conducted EMI model developed earlier by Lin [1]. Both measurements and simulation for conducted EMI are performed to verity the high frequency model proposed earlier by Lin [1]. The application circuit is that of boost power factor correctors. Experiment steps: (1) simulation of a boost power factor corrector in operation to identify low frequency problems, (2) including high frequency characteristics in low frequency component models to account for the 150 kHz ~ 30 MHz frequency range of conducted EMI in practical measurements. First, measurements and simulation for each separate component are conducted to verify their impedances and phase curves. The model is included in the circuit to simulate conducted EMI. Finally, simulation and measured EMI noises are compared to investigate whether the model is suitable for the frequency range of conducted EMI or not. The problematic electromagnetic interference can be predicted. Thus, time and cost of circuit design can be reduced. Considering the results of applying high-frequency model by Lin [1], the comparison results show that the EMI of different circuits will have different influence factors, including circuit structure, component characteristics, circuit design, PCB layout, and so on. Therefore, the high-frequency model should be concerned about more parameters, such as working temperatures of components, the permeability of magnetic components, and so on, for designing a further complete high-frequency model. In addition, the factors influencing EMI also include some environmental problems, such as the testing cables of measuring instruments, noise value, and so on. Thus, if the condition mentioned above can be considered, the model will facilitate EMI simulations of circuits.
Hung, Yu Chia, and 游嘉弘. "Losses Locating and Conducted EMI Analysis of Switching Power Supply with Assistance of Infrared Thermal Analyzer." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/19322466586228801316.
Повний текст джерела長庚大學
電機工程研究所
94
This thesis studies losses locating and conducted EMI analysis of a flyback switching power supply with the assistance of an infrared thermal analyzer. First, a switching mode flyback power supply is implemented as a test target. Then, an infrared thermal analyzer is used for locating the losses of circuit elements in this power supply. Further more, in order to evaluate the conducted EMI affected by heat from losses, the conducted EMI measurement is also made. The test results show that the infrared thermal analyzer is a useful analysis tool for thermal locating of switch power supply. The suppression of conducted EMI by using proper thermal dissipation is possible.
Shu, Yu, and 舒予. "Separation of Common-mode and Differential-mode Conducted Emission Using Software Approximation and EMI Filter Design." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/58283682029350337030.
Повний текст джерела輔仁大學
電子工程學系
92
A software approximation is proposed to separate the common-mode (CM) and differential-mode (DM) conducted emission for the power line EMI filter design of a switching mode power supply (SMPS). The computerized design environment bases on the LabView test and measurement system. Both the CM and DM noises can be separated using the software algorithm without the hardware implementation. The separation and the EMI filter designe results are compared with the conventional method. The filter designe results and experiment show that the proposed approximation can provide a user friendly and convincible approach for EMI countermeasure and EMC education.
Wolmarans, Pieter Johannes. "Investigation of a class of distributed planar conducted RF-EMI filters for integration in power electronic converters." Thesis, 2009. http://hdl.handle.net/10210/2187.
Повний текст джерелаIn power electronics most applications are custom designed. Even though similar topologies are used, each application is designed to fit specific requirements. Presently there is a move towards standard modules that can be connected together to perform the desired power conversion, in much the same way as IC’s have been used for a few decades now. It is important to ensure that the modules can work together without performance degradation. The close proximity of active, passive and logic devices in high power applications dramatically increases the risk of EMI between the various components. This document describes the design and characterisation of a planar conducted RF-EMI power line filter to be used between modules and between modules and power supplies. The filter consists of two sets of transmission lines in parallel. The first is a high permittivity material with nickel conductors, referred to as the attenuator. The second is a set of copper conductors that are placed on the outside of the attenuator. The filter must be able to remove conducted differential mode noise from power line to the module and from the module tot the power line. The filter dimensions are comparable to the wavelengths that have to be attenuated. This allows for a possible combination of RF filtering techniques and power line filtering techniques. The design of the filter and the electromagnetic effects that govern its behaviour is explained. The transfer characteristic of the filter is made possible by the choice of materials and their relation to each other. Each material is discussed and evaluated. Characterisation methods are described and results presented. The influence the materials have on the performance of the filter and the methods and problems of construction of the filter are discussed. The construction of the filter and the commercial processes available are discussed. A prototype filter was built to demonstrate the feasibility of the construction processes. The performance of the prototype filter was then measured. The various test set-ups for different applications are explained. Small signal tests in 50 W systems were used to allow for comparisons with other filter types. The prototype has minimal insertion loss in the pass band and an average slope of attenuation of 40 dB/decade beyond the corner frequency. The corner frequency is at 1 MHz. Transmission line theory is used to develop a distributed element model for the filter using the ABCD-matrix representation of transmission lines. From this matrix an equivalent P-model can be calculated. Applicable assumptions are made to simplify the equations and values for a lumped element P-model is calculated. Both models indicate the importance that the material parameters have on the performance of the simulation results. Good correlation between the measured performance and simulated performance is established. The material parameters are sensitive to temperature. A one-dimensional thermal model is presented to estimate the operating temperature of the filter. It is determined that the attenuation of the filter is primarily determined by the attenuator. Based on the findings, new attenuator designs are made in an attempt to improve the performance of the filter. The small signal measurements of the various designs and the test results under load conditions are compared. A power test is performed. The filter performance varies as the voltage rating is increased. Finally, a temperature characterisation is done. The filter is absorptive and heat is dissipated in both the conductors and the dielectric material. The filter performance is sensitive to the operating temperature. A summary of the technology and the evaluation of this type of filter are presented in the conclusion.