scholarly journals Improvement of Low-Frequency Radiated Emission in Electric Vehicle by Numerical Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Feng Gao ◽  
Chengkai Ye ◽  
Zilong Wang ◽  
Xu Li
Keyword(s):  
Numerical Analysis ◽  
Numerical Method ◽  
Electric Vehicle ◽  
Network Theory ◽  
Electromagnetic Interference ◽  
Low Frequency ◽  
Electronic Component ◽  
Radiated Emissions ◽  
Multiport Network ◽  
Radiated Emission

In this paper, a methodology for improving vehicle-level radiated electromagnetic interference (EMI) in electric vehicle (EV) is proposed. This methodology predicts vehicle-level radiated EMI by using the multiport network theory, based on analyzing the contribution from each electronic component to find out the main EMI source. To validate its effectiveness, the proposed methodology is applied in an actual EV for low-frequency radiated emissions. Simulation in a commercially available electromagnetics software and measurement in the EV are combined to predict the vehicle-level emissions, and then the electronic component with the greatest EMI that causes failure to meet the EMC standard is identified. After improving this component, the vehicle-level radiated emission is reduced to comply with the EMC standard, proving that the presented numerical method is effective. The proposed methodology can also be used in other EMC issues, regardless of the amount of interference sources and sensitive equipment.

scholarly journals A Topology-Based Approach to Improve Vehicle-Level Electromagnetic Radiation

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 364 ◽  
Author(s):  
Cunxue Wu ◽  
Feng Gao ◽  
Hanzhe Dai ◽  
Zilong Wang
Keyword(s):  
Complex System ◽  
Electromagnetic Radiation ◽  
Electric Vehicle ◽  
Electromagnetic Compatibility ◽  
Electromagnetic Coupling ◽  
Low Frequency ◽  
Experimental Results ◽  
Analysis Method ◽  
Network Parameters ◽  
Radiated Emissions

The popularity of the electric vehicle (EV) brings us many challenges of electromagnetic compatibility (EMC). Automotive manufacturers are obliged to keep their products in compliance with EMC regulations. However, the EV is a complex system composed of various electromagnetic interferences (EMI), sensitive equipment and complicated coupling paths, which pose great challenges to the efficient troubleshooting of EMC problems. This paper presents an electromagnetic topology (EMT) based model and analysis method for vehicle-level EMI prediction, which decomposes an EV into multi-subsystems and transforms electromagnetic coupling paths into network parameters. This way, each part could be modelled separately with different technologies and vehicle-level EMI was able to be predicted by algebra calculations. The effectiveness of the proposed method was validated by comparing predicted vehicle-radiated emissions at low frequency with experimental results, and application to the troubleshooting of emission problems.

Adsorption on heterogeneous surfaces: Numerical analysis of models for the Dubinin-Radushkevich equation

1981 ◽  
Vol 46 (8) ◽  
pp. 1709-1721 ◽  
Author(s):  
Miloš Smutek ◽  
Arnošt Zukal
Keyword(s):  
Integral Equation ◽  
Numerical Analysis ◽  
Numerical Method ◽  
Adsorption Behaviour ◽  
Heterogeneous Surfaces ◽  
Strong Energy ◽  
Adsorption On Heterogeneous Surfaces ◽  
Heterogeneity Parameter ◽  
Adsorption Energies ◽  
Mobile Adsorption

A numerical method, based on the integral equation of the adsorption on energy heterogeneous surfaces, is suggested for the evaluation of overall isotherm. It is shown that for the distribution of adsorption energies given by Eq. (1.11) and different models of the adsorption behaviour, the overall isotherms obey approximately the Dubinin-Radushkevich equation. The strong energy heterogeneity smears effectively the differences between the localized and mobile adsorption and leads to the same character of the overall isotherm with only a slightly changed heterogeneity parameter.

scholarly journals Electric Vehicle Battery Performance Investigation Based on Real World Current Harmonics

Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 489 ◽  
Author(s):  
Sid-Ali Amamra ◽  
Yashraj Tripathy ◽  
Anup Barai ◽  
Andrew D. Moore ◽  
James Marco
Keyword(s):  
Electric Vehicle ◽  
Real World ◽  
Low Frequency ◽  
Single Frequency ◽  
Current Harmonics ◽  
Battery Systems ◽  
Electric Vehicle Battery ◽  
Dc Bus ◽  
Dc Current ◽  
The Impact

Electric vehicle (EV) powertrains consist of power electronic components as well as electric machines to manage the energy flow between different powertrain subsystems and to deliver the necessary torque and power requirements at the wheels. These power subsystems can generate undesired electrical harmonics on the direct current (DC) bus of the powertrain. This may lead to the on-board battery being subjected to DC current superposed with undesirable high- and low- frequency current oscillations, known as ripples. From real-world measurements, significant current harmonics perturbations within the range of 50 Hz to 4 kHz have been observed on the high voltage DC bus of the EV. In the limited literature, investigations into the impact of these harmonics on the degradation of battery systems have been conducted. In these studies, the battery systems were supplied by superposed current signals i.e., DC superposed by a single frequency alternating current (AC). None of these studies considered applying the entire spectrum of the ripple current measured in the real-world scenario, which is focused on in this research. The preliminary results indicate that there is no difference concerning capacity fade or impedance rise between the cells subjected to just DC current and those subjected additionally to a superposed AC ripple current.

scholarly journals Pendulum-Type Hetero-Core Fiber Optic Accelerometer for Low-Frequency Vibration Monitoring

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2528 ◽  
Author(s):  
Hiroshi Yamazaki ◽  
Ichiro Kurose ◽  
Michiko Nishiyama ◽  
Kazuhiro Watanabe
Keyword(s):  
Fiber Optics ◽  
Electromagnetic Interference ◽  
Large Scale ◽  
Fiber Optic ◽  
Low Frequency ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Vibration Measurement ◽  
Displacement Sensor ◽  
Core Fiber

In this paper, a novel pendulum-type accelerometer based on hetero-core fiber optics has been proposed for structural health monitoring targeting large-scale civil infrastructures. Vibration measurement is a non-destructive method for diagnosing the failure of structures by assessing natural frequencies and other vibration patterns. The hetero-core fiber optic sensor utilized in the proposed accelerometer can serve as a displacement sensor with robustness to temperature changes, in addition to immunity to electromagnetic interference and chemical corrosions. Thus, the hetero-core sensor inside the accelerometer measures applied acceleration by detecting the rotation of an internal pendulum. A series of experiments showed that the hetero-core fiber sensor linearly responded to the rotation angle of the pendulum ranging within (−6°, 4°), and furthermore the proposed accelerometer could reproduce the waveform of input vibration in a frequency band of several Hz order.

scholarly journals Numerical analysis of stress distribution generated in spherical polyethylene inserts by knee joint endoprotheses’ sleds

2019 ◽  
Vol 21 (2) ◽  
pp. 1-5
Author(s):  
Marcin Nabrdalik ◽  
Michał Sobociński
Keyword(s):  
Numerical Analysis ◽  
Finite Elements ◽  
Stress Distribution ◽  
Knee Joint ◽  
Titanium Alloys ◽  
Numerical Method ◽  
Ti6al4v Alloy ◽  
Finite Elements Method ◽  
Weak Points ◽  
Metal Materials

Abstract The paper presents analysis of stress distribution in the friction node of knee joint endoprosthesis where sleds are made of various titanium alloys and CoCrMo cooperate with spherical polyethylene inserts. Currently used titanium alloys consists of Nb, Ta, Zr or Mo and with lesser value of Young’s modulus than Ti6Al4V alloy, or steel CoCrMo, which significantly varies from other metal materials. The obtained results make it possible to indicate the “weak points” of the accepted solution, and thus counteract the subsequent effects resulting from premature wear of endoprosthesis elements. The analysis was conducted with numerical method of ADINA System 8.6. The Finite Elements Method allowed to compute and present stress distribution quickly in all elements of the model.

scholarly journals Alternating (AC) Loop Current Attacks Against the KLJN Secure Key Exchange Scheme

2021 ◽  
pp. 2150050
Author(s):  
Mutaz Y. Melhem ◽  
Christiana Chamon ◽  
Shahriar Ferdous ◽  
Laszlo B. Kish
Keyword(s):  
Electromagnetic Interference ◽  
High Frequency ◽  
Practical Importance ◽  
Low Frequency ◽  
Key Exchange ◽  
Power Density Spectrum ◽  
Voltage Source ◽  
Loop Current ◽  
Johnson Noise ◽  
Density Spectrum

Recently, several passive and active attack methods have been proposed against the Kirchhoff–Law–Johnson–Noise (KLJN) secure key exchange scheme by utilizing direct (DC) loop currents. The DC current attacks are relatively easy, but their practical importance is low. On the other hand, parasitic alternating (AC) currents are virtually omnipresent in wire-based systems. Such situations exist due to AC ground loops and electromagnetic interference (EMI). However, utilizing AC currents for attacks is a harder problem. Here, we introduce and demonstrate AC current attacks in various frequency ranges. The attacks exploit a parasitic/periodic AC voltage-source at either Alice’s or Bob’s end. In the low-frequency case, the procedure is the generalized form of the former DC ground-loop-based attack. In the high-frequency case, the power density spectrum of the wire voltage is utilized. The attack is demonstrated in both the low and the high-frequency situations. Defense protocols against the attack are also discussed.

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