scholarly journals What Is the Effect of Outer Jacket Degradation on the Communication Parameters? A Case Study of the Twisted Pair Cable Applied in the Railway Industry

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 972
Author(s):  
Damian Grzechca ◽  
Dariusz Zieliński ◽  
Wojciech Filipowski
Keyword(s):  
Transmission Lines ◽  
Environmental Conditions ◽  
Railway Transportation ◽  
Temperature Deviation ◽  
Twisted Pair ◽  
Distributed Parameters ◽  
Proposed Model ◽  
Transmission Reliability ◽  
Frequency Domains ◽  
Railway Industry

Among the variety of problems encountered in transmission lines, the outer jacket degradation-derived faults of communication cables in railway applications have a significant impact on the transmission line parameters, especially if the cables are exposed to extremely varying environmental conditions, such as temperature deviation and humidity changes. In this paper, an advanced model of a twisted pair communication cable is proposed, together with approximated degradation functions for distributed parameters of the model, such as the shielding inductance, resistance, and capacitance per meter of cable length. This allows for gathering the distributed parameters for the proposed model under specific environmental conditions. The degradation functions for the parameters have been identified and compared with simulation results, including the communication speed and frequency band, and it has been confirmed that the transmission reliability depends on the cable condition. The authors discuss the influence of outer jacket degradation on signal behavior in terms of time and frequency domains that should be considered while developing new signaling devices for railway transportation.

scholarly journals TRANSIENT RESPONSE OF A DISTRIBUTED RLC INTERCONNECT BASED ON DIRECT POLE EXTRACTION

2009 ◽  
Vol 18 (07) ◽  
pp. 1263-1285 ◽  
Author(s):  
GUOQING CHEN ◽  
EBY G. FRIEDMAN
Keyword(s):  
Closed Form ◽  
Transient Response ◽  
Transmission Lines ◽  
Average Error ◽  
Proposed Model ◽  
Newton Raphson ◽  
On Chip ◽  
Interconnect Systems ◽  
Interconnect System ◽  
Raphson Method

With higher operating frequencies, transmission lines are required to model global on-chip interconnects. In this paper, an accurate and efficient solution for the transient response at the far end of a transmission line based on a direct pole extraction of the system is proposed. Closed form expressions of the poles are developed for two special interconnect systems: an RC interconnect and an RLC interconnect with zero driver resistance. By performing a system conversion, the poles of an interconnect system with general circuit parameters are solved. The Newton–Raphson method is used to further improve the accuracy of the poles. Based on these poles, closed form expressions for the step and ramp response are determined. Higher accuracy can be obtained with additional pairs of poles. The computational complexity of the model is proportional to the number of pole pairs. With two pairs of poles, the average error of the 50% delay is 1% as compared with Spectre simulations. With ten pairs of poles, the average error of the 10%-to-90% rise time and the overshoots is 2% and 1.9%, respectively. Frequency dependent effects are also successfully included in the proposed method and excellent match is observed between the proposed model and Spectre simulations.

scholarly journals Modeling Features of a Single Phase-to-Earth Fault in a Medium Voltage Overhead Transmission Line

2020 ◽  
Vol 4 (2) ◽  
pp. 127-138
Author(s):  
Ismael Saeed ◽  
Kamal Sheikhyounis
Keyword(s):  
Transmission Line ◽  
Transmission Lines ◽  
Single Phase ◽  
Single Frequency ◽  
Mathematical Representation ◽  
Medium Voltage ◽  
Overhead Transmission Line ◽  
Earth Fault ◽  
Distributed Parameters ◽  
Selection Of

The modeling and calculation of a single phase-to-earth fault of 6 to 35 kV have specific features when compared with circuits with higher nominal voltages. In this paper, a mathematical analysis and modeling of a 3-phase overhead transmission line with distributed parameters consisting of several nominal T-shaped, 3-phase links with concentrated parameters replaced by 1 nominal T-shaped link were carried out. Further analysis showed that not accounting for the distributed nature of the line parameters did not cause significant errors in the assessment of the maximum overvoltage in the arc suppression in single phase-to-earth faults, and that sufficient accuracy insures the representation of the line by only 1 nominal T-shaped, 3-phase link. Such a modeling technique makes it impossible to identify the location of single-phase faults, which is the property of higher harmonic amplification of individual frequencies. Chain equivalent schemas with constant parameters are valid for a single frequency, thereby providing an opportunity to study the nature of the wave process by the discrete selection of parameters. Next in the mathematical representation, we consider the overhead transmission lines as lines with distributed parameters.

scholarly journals Coordinated Dispatch of Integrated Energy Systems Considering the Differences of Multiple Functional Areas

2019 ◽  
Vol 9 (10) ◽  
pp. 2103 ◽  
Author(s):  
Liusong Li ◽  
Weichao Jin ◽  
Meiyan Shen ◽  
Li Yang ◽  
Fei Chen ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Electric Vehicles ◽  
Transmission Lines ◽  
Distribution System ◽  
Energy Systems ◽  
Actual Distribution ◽  
Integrated Energy Systems ◽  
Transmission Distance ◽  
Proposed Model ◽  
Functional Areas

A large amount of wind turbine power and photovoltaic power is abandoned in many areas with abundant renewable energy due to thermal-electric coupling, inadequate local consumption capacity, and limited capacity of transmission lines, etc. To solve the above problems, a coordinated dispatching method for integrated energy systems is proposed in this paper. Firstly, the spatiotemporal characteristics of diversified loads in multiple functional areas are introduced, including the inertia and elasticity of heating/cooling loads, the spatiotemporal distribution of electric vehicles, and the optimum transmission distance of diversified loads, etc. Secondly, a coordinated dispatching model of integrated energy systems is proposed, which considers the differences of multiple functional areas and various forms of energy systems. Finally, an actual distribution system in Jianshan District, Haining, Zhejiang Province of China is investigated for demonstrating the effectiveness of the proposed model. The results illustrate that the proposed model could effectively improve the consumption rate of renewable energy and reduce the volatility of renewable energy by considering the coordination of electric vehicles, tie lines, and heating/cooling systems in multiple functional areas.

scholarly journals Influence of Size of Source Effect on Accuracy of LWIR Radiation Thermometers

2016 ◽  
Vol 23 (4) ◽  
pp. 661-667
Author(s):  
David Cywiak ◽  
Daniel Cárdenas-García ◽  
Hugo Rodriguez-Arteaga
Keyword(s):  
Radiation Thermometer ◽  
Electrical Signal ◽  
Field Of View ◽  
Measured Temperature ◽  
Temperature Deviation ◽  
Source Effect ◽  
Long Wavelength ◽  
Proposed Model ◽  
Long Wavelength Infrared ◽  
Infrared Radiation Thermometer

Abstract Determining the size of source effect of a radiation thermometer is not an easy task and manufacturers of these thermometers usually do not indicate the deviation to the measured temperature due to this effect. It is one of the main uncertainty components when measuring with a radiation thermometer and it may lead to erroneous estimation of the actual temperature of the measured target. We present an empiric model to estimate the magnitude of deviation of the measured temperature with a long-wavelength infrared radiation thermometer due to the size of source effect. The deviation is calculated as a function of the field of view of the thermometer and the diameter of the radiating source. For thermometers whose field of view size at 90% power is approximately equal to the diameter of the radiating source, it was found that this effect may lead to deviations of the measured temperature of up to 6% at 200ºC and up to 14% at 500ºC. Calculations of the temperature deviation with the proposed model are performed as a function of temperature and as a function of the first order component of electrical signal.

Investigation on the skidding dynamic response of rolling bearing with local defect under elastohydrodynamic lubrication

2019 ◽  
Vol 20 (6) ◽  
pp. 615 ◽  
Author(s):  
Jianxiong Kang ◽  
Yanjun Lu ◽  
Yongfang Zhang ◽  
Cheng Liu ◽  
Sha Li ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Elastohydrodynamic Lubrication ◽  
Rolling Bearing ◽  
Interaction Force ◽  
Local Defect ◽  
Proposed Model ◽  
Significant Difference ◽  
Frequency Domains ◽  
Rolling Element ◽  
Time And Frequency Domains

The rolling element skidding may lead to the failure of the rolling bearing. The skidding characteristics can be effectively analyzed by using dynamic response of the rolling bearing. A dynamic model is established to investigate the vibration response of the rolling bearing with local defect on inner/outer race in this paper. In the proposed model, the rolling element skidding, contact stiffness and displacement, the interaction force between ball and race, the interaction force between cage and race, elastohydrodynamic lubrication are taken into consideration. The dynamic responses of the rolling bearing with the rolling element skidding are solved by the proposed model in the time and frequency domains. The effects of defect size, rotational speed, external load, and compound factors on skidding characteristics are investigated. The proposed model is verified by the experiments. The results show that the rolling element skidding leads to the significant difference of dynamic characteristics in the time and frequency domains, which aggravates the failure of the rolling bearings.

scholarly journals On the Eddy Current Losses in Metallic Towers

2020 ◽  
Vol 9 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Ibrahim Mahariq ◽  
Svetlana Beryozkina ◽  
Huda Mohammed ◽  
Hamza Kurt
Keyword(s):  
Magnetic Field ◽  
Transmission Lines ◽  
Power Loss ◽  
Eddy Currents ◽  
Low Voltage ◽  
Power Network ◽  
Geometrical Structures ◽  
Proposed Model ◽  
New Type ◽  
First Time

The existence of magnetic field around high-voltage overhead transmission lines or low-voltage distribution lines is a known fact and well-studied in the literature. However, the interaction of this magnetic field either with transmission or distribution towers has not been investigated. Noteworthy it is to remember that this field is time-varying with a frequency of 50 Hz or 60 Hz depending on the country. In this paper, we studied for the first time the eddy currents in towers which are made of metals. As the geometrical structures of towers are extremely complex to model, we provide a simple approach based on principles of electromagnetism in order to verify the existence of power loss in the form of eddy currents. The frequency-domain finite difference method is adapted in the current study for simulating the proposed model. The importance of such a study is the addition of a new type of power loss to the power network due to the fact that some towers are made of relatively conductive materials.©2020. CBIORE-IJRED. All rights reserved

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