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[IEEE 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - Atlanta, GA, USA (2018.10.31-2018.11.2)] 2018 IEEE 6th Workshop on Wide Bandgap Power Devices and Applications (WiPDA) - EMI Analysis of a High Power Silicon Carbide Two-level Inverter
摘要： Successive generations of aircraft demand more electrical energy as pneumatic and hydraulic systems are replaced with electrical components. The more electric aircraft (MEA) transformation aims to improve fuel economy, increase reliability, and lower operating costs. To fully enjoy the benefits of an additional improvements in the power density of the electrical distribution system are required. Silicon carbide (SiC) devices have many advantages over their silicon (Si) counterparts that can lead to improvements in the power density. However, their characteristically switching speeds can result in higher levels of electromagnetic interference (EMI). This research compares the performance of two high power three phase inverters; one is built from SiC MOSFETs and the other from Si IGBTs. The efficiency and conducted EMI are measured at a DC bus of 540 V and an output power exceeding 25 kW.
关键词： Silicon Carbide,Electromagnetic Interference (EMI),More Electric Aircraft
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Common Mode Noise Analysis for a High Step-Up Converter with GaN Devices
摘要： High Step-up converters have numerous applications in renewable energy systems and electric automotive industry. To improve the power density, an interleaved high step-up boost converter with coupled inductor was proposed. However, for practical applications is compulsory that this topology must comply with the CISPR standards. Therefore, to identify the noise sources in the analyzed converter, an equivalent noise modelling is conducted. These models revealed the dependency of inductor windings on different noise sources. For experimental analysis of the conducted emissions of this topology, GaN FETs based prototype is designed. Several tests were carried out to find the effect of various factors on noise emission. As results of tests, 1) Increasing the switching frequency generates increase in the noise spikes 2) Noise emissions from the converter do depend on its mode of operation 3) High peaks of noise are generated at low frequency range by reducing the voltage transition time across the switch.
关键词： Coupled-Inductor,High Step-Up,GaN FETs,CM Noise,DC-DC Converter,EMI Noise
更新于2025-09-23 15:22:29
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Electrical and Electromagnetic Interference (EMI) shielding properties of hexagonal boron nitride nanoparticles reinforced polyvinylidene fluoride nanocomposite films
摘要： The hexagonal boron nitride nanoparticles (h-BNNPs) reinforced flexible polyvinylidene fluoride (PVDF) nanocomposite films were prepared via a simple and versatile solution casting method. The morphological, thermal and electrical properties of h-BNNPs/PVDF nanocomposite films were elucidated. The electromagnetic interference (EMI) shielding properties of prepared nanocomposite films were investigated in the X-band frequency regime (8–12 GHz). The EMI shielding effectiveness (SE) was increased from 1 dB for the PVDF film to 11.21 dB for the h-BNNPs/PVDF nanocomposite film containing 25 wt% h-BNNPs loading. The results suggest that h-BNNPs/PVDF nanocomposite films can be used as lightweight and low-cost EMI shielding materials.
关键词： Hexagonal boron nitride,PVDF,SEM,EMI shielding,DSC,electrical properties
更新于2025-09-23 15:21:21
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Design and Implementation of 150 W AC/DC LED Driver with Unity Power Factor, Low THD, and Dimming Capability
摘要： This paper presents the implementation of a two-stage light-emitting diode (LED) driver based on commercial integrated circuits (IC). The presented LED driver circuit topology, which is designed to drive a 150 W LED module, consists of two stages: AC-DC power factor correction (PFC) stage and DC/DC power converter stage. The implementation of the PFC stage uses IC NCP1608, which uses the critical conduction mode to guarantee a unity input power factor with a wide range of input voltages. The DC/DC power converter with soft-switching characteristics for the entire load range uses IC FLS2100XS. Furthermore, the design of an electromagnetic interference (EMI) filter for the LED driver and the dimming control circuit are discussed in detail. The hardware prototype, an LED lighting system, with a rated power of 150 W/32 V from a nominal 220 V/50 Hz AC voltage supply was tested to show the effectiveness of the design. The presented LED driver was tested for street lighting, and the experimental results show that the power factor (PF) was higher than 0.97, the total harmonics distortion (THD) was lower than 7%, and the efficiency was 91.7% at full load. The results prove that the performance of the presented LED driver complies with the standards: IEC61000-3-2 and CIRSP 15:2009.
关键词： EMI filter,power factor correction,LED driver,LLC resonant converter
更新于2025-09-23 15:19:57
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Variable densification of reduced graphene oxide foam into multifunctional high-performance graphene paper
摘要： Super-flexible, electrically and thermally conductive graphene-based papers are in great demand in the fields of electronics and supercapacitors. However, the applications of graphene-based papers are limited either by their brittleness, small scale, or by their unsatisfactory thermal conductivity. Conventionally, such papers are fabricated by vacuum-assisted filtration, direct evaporation, electrospray coating, or wet spinning. Here we propose a novel strategy, namely, direct densification of reduced graphene oxide foam, to fabricate large-scale multifunctional graphene papers. The graphene paper density could be adjusted by applying different loads. The densities of the graphene papers varied from 0.32 g cm?3 to 1.85 g cm?3. The thermal conductivity, tensile stress, electrical conductivity and electromagnetic interface shielding effectiveness increased with an increase in the density of the graphene paper. When the density of the graphene paper reached 1.85 g cm?3, the tensile stress was up to 50.4 MPa with strain of 4%, the thermal conductivity was 1103 W m?1 K?1 at room temperature and there was high electrical conductivity of 1.1 × 10? S m?1, as well as an electromagnetic interference (EMI) shielding effectiveness of 77.2 dB. Our new strategy is very promising in terms of controlling the thickness, density, and size of graphene paper.
关键词： graphene paper,densification,EMI shielding,electrical conductivity,thermal conductivity
更新于2025-09-19 17:15:36
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Hybrid composite mats composed of amorphous carbon, zinc oxide nanorods and nickel zinc ferrite for tunable electromagnetic interference shielding
摘要： With the rapid growth of electronics and telecommunication industries, electromagnetic pollution is a serious concern to be addressed because it not only affects the sensitivity and performance of the devices but also affects human’s health. Here, we report lightweight hybrid composite mats, having porosity around 40%, composed of amorphous carbon, zinc oxide nanorods and nickel zinc ferrite for excellent electromagnetic interference (EMI) shielding in the X-band (8.2-12.4 GHz). The vibrating sample magnetometer measurement confirmed that the saturation magnetization value (Ms) of the composite materials enhances with the weight percentage of zinc oxide nanorods-nickel zinc ferrite (ZNF) powder, which leads to enhanced magnetic loss of the electromagnetic waves. With the thickness of 1.0 mm, the total EMI shielding effectiveness of the amorphous carbon composite was measured to be 25.70 dB which was further enhanced to 53 dB by the incorporation of the ZNF powder. Such high increment is attributed to the enhanced magnetic properties, interfacial polarization and dielectric properties of the composite. The synergistic combination of the materials results in the high reflection coefficient and absorption coefficient of the composites which were measured to be ~0.916 and ~0.083, respectively. Thus, the composites can shield up to 99.999% power of the electromagnetic waves which is shared by the 8.394% reflection and 91.605% absorption. Moreover, the magnetic, electrical and EMI shielding properties of the composites can be tuned by controlling the amount of ZNF powder in composites. Hence, the composite mats can be suitable for applications in defense and telecommunication.
关键词： A. Hybrid,A. Nano-structures,EMI shielding,B. Magnetic properties,B. Electrical properties
更新于2025-09-19 17:15:36
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[IEEE 2019 International Symposium on Electromagnetic Compatibility - EMC EUROPE - Barcelona, Spain (2019.9.2-2019.9.6)] 2019 International Symposium on Electromagnetic Compatibility - EMC EUROPE - Propagation of Laser-Driven Electromagnetic Pulses in Laser Target Areas
摘要： During high intense laser target interaction a strong electromagnetic pulse (EMP) is generated which can potentially disturb the well performing of the experiment. The electromagnetic interference (EMI) due to the EMP not only affects devices present in the vacuum chamber but also in the target area where it may compromise the performance or operation of electronics and device controllers. In this work we report the measurements of EMP inside the laser target area at Centro de Laseres Pulsados (CLPU) during high intense laser-target interaction experiments. The experimental results show how the amplitude and spectrum of the EMP in the target area is different from the one inside the target chamber (TC). At last Finite element method (FEM) simulation results are shown and compared with experimental results.
关键词： laser-plasma interaction,Electromagnetic interference (EMI),High Intense laser,Electromagnetic Pulse (EMP),Finite Element Method (FEM) simulations
更新于2025-09-16 10:30:52
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[IEEE 2019 International Symposium on Electromagnetic Compatibility - EMC EUROPE - Barcelona, Spain (2019.9.2-2019.9.6)] 2019 International Symposium on Electromagnetic Compatibility - EMC EUROPE - Evaluation of Electromagnetic Noise Radiated from Tube-type LED Lamps and Its Effect on Wireless Medical Telemetry Systems
摘要： Light-emitting diode (LED) lamps have been widely introduced in the healthcare field. On the other hand, electromagnetic interference with wireless medical telemetry systems by switched-mode power supplies built in LED lamps has been a serious problem. We have investigated electromagnetic noise radiated from bulb-type LED lamps and its effect on wireless medical telemetry systems. In this study, we focus on tube-type LED lamps and investigated the statistical characteristics of electromagnetic noise radiated from them. Additionally, the critical reception of wireless medical telemetry systems subjected to interference by tube-type LED lamp installation was investigated.
关键词： light-emitting diode (LED),Gaussian approximation,receiver sensitivity,switched-mode power supply,wireless medical telemetry system,impulsive noise,electromagnetic interference (EMI)
更新于2025-09-16 10:30:52
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[IEEE 2019 International Symposium on Electromagnetic Compatibility - EMC EUROPE - Barcelona, Spain (2019.9.2-2019.9.6)] 2019 International Symposium on Electromagnetic Compatibility - EMC EUROPE - Modeling of conducted EMI noise in an Automotive LED Driver Module with DC/DC Converters
摘要： When transferring power from source to LED matrix, the electromagnetic interference (EMI) noise is generated. Moreover, the dc-dc converter with switching operation contains a wide range of harmonics. Therefore, it is important to predict the EMI noise in an automotive LED driver module. In this study, we firstly simulated conducted noise from the automotive LED driver module. The ringing noise of the dc-dc converter has been analyzed and simulated by using a circuit simulation. In order to simulate conducted EMI noise, parasitic components of power transfer line trace, passive components such as capacitor and inductor, active components such as diode and switching device, cable between PCB board and LED matrix, and connector in the LED driver module are considered. The simulation and measurement setup for conducted emissions are directed by CISPR 25 standard.
关键词： LED Driver,LDM,EMI,Conducted Emission,dc-dc Converter
更新于2025-09-16 10:30:52
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Analysis and Modeling of Conducted EMI From an AC–DC Power Supply in LED TV up to 1 MHz
摘要： Critical conduction mode (CRM) boost power factor correction (PFC) converter is widely used in ac–dc power supplies to achieve high power factor. The switching frequency varies in a half-line cycle. In this article, both the differential-mode (DM) and common-mode (CM) electromagnetic interference (EMI) noises below 1 MHz from the ac–dc power supply in a LED TV are analyzed and modeled. The power supply consists of two parts: CRM boost PFC converter and LLC resonant converter. The conducted EMI noise and noise source voltages are measured in the time domain and then converted to the frequency domain via short-time fast Fourier transform (STFFT). Through the joint time-frequency analysis using STFFT, the drain-to-source voltage of the power MOSFET in the PFC converter is identified as the dominant noise source of both CM and DM EMI below 1 MHz from the power supply. The EMI current path changes during different periods of a cycle of the line voltage. During most time of a cycle, two diodes of the bridge rectifier are forward biased, and the bridge rectifier can be treated as short circuit. The current paths of DM and CM EMI are explained and modeled by a linear equivalent circuit model. Three parasitic capacitances need to be considered to model the CM EMI noise in this device under test. From the circuit model, transfer functions relating DM and CM EMI spectra to noise source voltage spectrum are obtained. The conducted EMI spectra is predicted by multiplying the spectrum of noise source voltage by the transfer functions. The prediction matches with measurement. The effects of parasitic capacitances on CM EMI noise are analyzed by simulation and then validated by measurement. The analysis can help with EMI design to reduce the CM EMI.
关键词： conducted emissions (CE),differential mode (DM),Common mode (CM),electromagnetic interference (EMI),switched-mode power supply (SMPS),critical conduction mode (CRM),power factor correction (PFC)
更新于2025-09-12 10:27:22