scholarly journals Using N-Norms for Analyzing Symmetric Protective Electrical Circuits with Triple Modal Reservation

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2390
Author(s):  
Yevgeniy S. Zhechev ◽  
Anna V. Zhecheva ◽  
Alexey A. Kvasnikov ◽  
Alexander M. Zabolotsky
Keyword(s):  
Modal Analysis ◽  
Electromagnetic Compatibility ◽  
High Efficiency ◽  
Electromagnetic Coupling ◽  
Total Duration ◽  
Ultra Wideband ◽  
Primary Circuit ◽  
Suggested Approach ◽  
Lower Amplitude ◽  
Trapezoidal Pulse

The redundancy of functional blocks and critical assemblies in radio-electronic equipment is among the most widely used techniques for increasing reliability. Complex redundant systems raise the problem of electromagnetic compatibility (EMC). Ignoring EMC requirements can lead to partial or complete REE failures. In this paper, the authors analyze a noise-protective electrical circuit with triple modal reservation (a promising type of cold redundancy). A multilayer stripline is investigated, the conductors of which are symmetrically arranged relative to two planes. On account of the strong electromagnetic coupling, this protective circuit can decompose dangerous ultra-wideband (UWB) interference received at the input of the primary or redundant circuits into unipolar pulses of lower amplitude. Using this approach, due to the symmetry of the conductors, equal decomposition efficiency could be achieved. However, the effect of UWB interference at the input of one of the conductors produces bipolar pulses at the output of the other conductors. In this paper, the authors evaluate the dangers of unipolar and bipolar decomposed pulses and use modal analysis to mathematically determine the polarities and amplitudes of the decomposed pulses at all output nodes for a pseudo-matched structure. By using the quasistatic approach with and without losses, the time responses to a trapezoidal pulse with a total duration of 60 ps, which simulates UWB interference, are obtained. To confirm the results of modal analysis and quasistatic simulation, an experimental study is performed. Using a stroboscopic oscilloscope DSA 8300, the authors obtained a transient response to a step excitation. Then, taking the derivative, the response to a trapezoidal pulse with a total duration of 140 ps was obtained. To analyze the criticality of the decomposed pulses, N-norms are used. In the general case, it is shown that the UWB interference is decomposed into four pulses of lower amplitude. At the same time, the value of each N-norm indicates its significant attenuation. For example, the amplitude of the UWB pulse acting on the input of the reserved conductor decreases by 10.31–8.93 times. Such results numerically demonstrate the high efficiency of the suggested approach when it comes to protecting equipment against UWB interference. It is also shown that the probability of dielectric breakdown and damage to electronic components in redundant circuits is lower than in a primary circuit. This is due to the fact that the value of N3 in the redundant circuit is 2.38 times less than in the primary circuit. However, the results demonstrate that arcing is highly probable both in primary and redundant circuits. Finally, aspects of symmetry/asymmetry in the problem under investigation are emphasized.

scholarly journals Обеспечение электромагнитной совместимости систем интеллектуального управления при появлении помех в судовых кабельных трассах

2020 ◽  
Author(s):  
A.M. Agafonov ◽  
A.A. Worshevsky ◽  
P.A. Vorshevskii ◽  
E.S. Grishakov ◽  
A.S. Kornev
Keyword(s):  
Electromagnetic Interference ◽  
Electromagnetic Compatibility ◽  
Mutual Influence ◽  
Electromagnetic Coupling ◽  
Systems Design ◽  
Power Input ◽  
Travelling Wave ◽  
Normal Function ◽  
Input Output ◽  
Digital Technique

Системы интеллектуального управления базируются на использовании цифровой техники и по своему принципу действия восприимчивы к внешним помехам. Изменения напряжения и тока в кабелях, электромагнитные поля могут привести к появлению в цепях передачи информации и питания систем напряжений, похожих на полезные сигналы, что приведет к сбоям в работе систем. Технология электромагнитной совместимости (ЭМС) призвана устранить взаимные влияния оборудования и обеспечить его нормальную работу в условиях действия помех. Кабельные трассы являются особенно значимым фактором для обеспечения ЭМС на судах. Помехи распространяются в кабелям от источников к чувствительному электронному оборудованию (ЭО). Метод распространяющихся волн дает возможность рассчитать изменения помех при распространении по кабелям. Силовые и информационные кабели могут прокладываться в одной трассе, что приводит к их электромагнитной связи. Рассмотренные модели оценивают наведенные напряжения в информационных кабелях при появлении помех в силовых кабелях. Параметры электромагнитной связи кабелей могут быть определены расчетным путем и экспериментально на основе предлагаемой методики. Приведенные рекомендации по снижение уровня излучаемых помех от кабельных трасс, снижению наведенных напряжений и выполнению экранирования призваны помочь разработчикам ЭО и систем в обеспечении ЭМС.Intellectual control systems are based on digital technique. Digital electronic equipment (EE) is the receptor of electromagnetic interference due to its function principle. EE malfunction can be caused by induced voltages in input/output and power supply circuits. Voltage and current changes in cables leads to electromagnetic noise and induced voltages. Protection technique for power, input/output, case and grounding ports can be used in equipment and ship systems design. Electromagnetic compatibility technique must eliminate mutual influence of EE and give normal function of EE in real electromagnetic environment. Cable run is important factor for EMC obtaining in ships. Noise voltage propagates in cable from noise source to sensitive EE. Voltage parameters can be calculated with travelling wave technique. There are power and information cables in shipboard cable run. Electromagnetic coupling of cables leads to voltages in one cable induced by voltages and current in other cable. Coupling models give possibility to calculate induced voltages. Parameters of coupling can be determined with calculation on the base of detailed information about cable run or with proposed experiment procedure. Proposed recommendations about cable emission decreasing, cables decoupling and shielding can be useful for EMC obtaining.

Dispersion distortions of wide spectrum signals during their propagation in the Earth ionosphere

Antennas ◽  
2021 ◽  
Author(s):  
M. M. Ivoylova ◽  
A. V. Kashin ◽  
V. A. Kozlov
Keyword(s):  
Electromagnetic Compatibility ◽  
Wide Spectrum ◽  
Radio Pulse ◽  
Current Trend ◽  
Polarization Plane ◽  
Leading Edge ◽  
Ultrashort Pulses ◽  
Ultra Wideband ◽  
Engineering Systems ◽  
Middle Latitudes

The current trend in the development of radio engineering systems (RES) is to use wide spectrum signals, the application of which provides an increase in the resolution and secrecy of the radar operation, an increase in the speed and volume of transmitted information for communication and telemetry systems. The class of such signals includes ultrashort pulses (USP signals), radio pulses with linear frequency modulation (chirp signals). Also of interest are ultra-wideband (UWB) noise signals (UWBN signals), which have high electromagnetic compatibility, stealth and noise immunity. When designing promising ground-based and space-based RES using wide spectrum signals, an important task is to determine the distortions of their envelope shape and distortions of spectrum, as well as the change in the polarization of the emitted wave when passing through the Earth's ionosphere, since taking these distortions into account will provide conditions for optimal reception. This article presents the numerical assessment results of the expected distortions of the wide spectrum signals main types of the decimeter wavelength range, for middle latitudes at heights from 100 km to 1000 km. The conversion of the emitted pulse into a frequency modulated radio pulse is typical for the USP signal. For a chirp radio pulse with a monotonically increasing frequency, an initial decrease in duration with an increase in amplitude and subsequent stretching in time with further spread is typical (the amplitude change is estimated due to a change in the signal shape without taking into account spread). For a chirp radio pulse with a monotonically falling frequency and a UWBN signal, dispersion distortions manifest themselves as an increase in their duration with a decrease in amplitude. For all signal types under consideration that have passed through the ionosphere, a leading edge lag is observed, the dependences of frequency on time at an altitude of 1000 km are repeated and are close to hyperbolic character, the energy spectra envelope shape of the considered signals is almost not distorted. The polarization plane rotation for signals with a spectrum concentrated in the frequency range above 0.7 GHz does not exceed 45

Urethane Energy Absorbers for Automobile Bumpers

1973 ◽  
Vol 46 (4) ◽  
pp. 843-861 ◽  
Author(s):  
P. A. Weller
Keyword(s):  
High Efficiency ◽  
Current Model ◽  
Test Device ◽  
Microcellular Foam ◽  
Real Thing ◽  
Suggested Approach ◽  
Current Specification ◽  
The Government ◽  
Energy Absorbers ◽  
In The Beginning

Abstract It is believed that the concepts and data presented here are not only useful for the design and application of urethane foam for bumpers, but demonstrate the inherent fitness of the material for this purpose. To review quickly the factors listed in the beginning of the paper: 1. Urethane-faced bumpers will not only prevent damage to the bumper or vehicle, but will eliminate or minimize damage to the object impacted. 2. Repeated tests at severe overloads have demonstrated the recoverability of the foam after repeated impacts. 3. High hysteresis of urethane results in minimum rebound. 4. The material is velocity responsive within the specification range. 5. A wide variety of usable arrangements plus ready moldability provide considerable styling freedom. 6. Temperature compensation features assure designable performance consistency. 7. High efficiency or form factor is achievable, resulting in minimum force and stroke. 8. No maintenance is required. 9. Urethane microcellular foam is among the lower cost plastic materials on a per pound basis. Low densities and discreet placement can result in very competitive systems. Steel stroking bumpers are designed to ward off blows with emphasis on protection of the vehicle on which they are mounted. As a result, they present a far more hostile motoring environment than ever before for anything or anyone except another similar bumper. Urethane bumpers have a great potential for creating a far less hostile environment for everyone and everything, including fronts and rears of current vehicles, sides of all vehicles, other objects, pedestrians, and occupants. The current specification severely inhibits the realization of that potential. Doing anything about it is no easy matter since it could easily lead into a specification of horrendous complexity. However, following is one suggested approach. In testing for occupant protection, a manikin or dummy is selected as a representative test device. It is by no means truly interchangeable with the real thing or all situations, but does provide a firm and representative means for reasonable evaluation and standardization. In like manner, it would be possible to select a reasonably typical front or rear current-model configuration to serve as a representative test device on the face of the pendulum, and simply specify “no damage to the test device” rather than “no contact to specified planes”. A manufacturer could be contracted with by the government to produce identical test devices for all who wished to run such tests. Such a specification could be amended to the current specification as an alternate, rather than attempting to revise what is already an excellent document for the steel stroking bumper.

High-efficiency modal analysis and deformation prediction of rice transplanter based on effective independent method

2020 ◽  
Vol 168 ◽  
pp. 105126
Author(s):  
Ji Jiangtao ◽  
Chen Kaikang ◽  
Jin Xin ◽  
Wang Zhaoyang ◽  
Dai Baoqiong ◽  
...  
Keyword(s):  
Modal Analysis ◽  
High Efficiency ◽  
Independent Method ◽  
Deformation Prediction

scholarly journals Efficiency of a Compact Elliptical Planar Ultra-Wideband Antenna Based on Conductive Polymers

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Thomas Kaufmann ◽  
Akhilesh Verma ◽  
Van-Tan Truong ◽  
Bo Weng ◽  
Roderick Shepherd ◽  
...  
Keyword(s):  
High Efficiency ◽  
Conductive Polymers ◽  
Thick Layer ◽  
Ultra Wideband ◽  
Planar Antenna ◽  
Frequency Range ◽  
Test Bed ◽  
Order Of Magnitude ◽  
Uwb Applications ◽  
Pedot Layer

A planar antenna for ultra-wideband (UWB) applications covering the 3.1–10.6 GHz range has been designed as a test bed for efficiency measurements of antennas manufactured using polymer conductors. Two types of conductive polymers, PEDOT and PPy (polypyrrole), with very different thicknesses and conductivities have been selected as conductors for the radiating elements. A comparison between measured radiation patterns of the conductive polymers and a copper reference antenna allows to estimate the conductor losses of the two types of conductive polymers. For a 158 μm thick PPy polymer, an efficiency of almost 80% can be observed over the whole UWB spectrum. For a 7 μm thick PEDOT layer, an average efficiency of 26.6% demonstrates, considering the room for improvement, the potential of this type of versatile materials as flexible printable alternative to conductive metallic paints. The paper demonstrates that, even though the PEDOT conductivity is an order of magnitude larger than that of PPy, the thicker PPy layer leads to much higher efficiency over the whole UWB frequency range. This result highlights that high efficiency can be achieved not only through high conductivity, but also through a sufficiently thick layer of conductive polymers.

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