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Travelling Waves for Finding the Fault Location in Transmission Lines
Issue:
Volume 1, Issue 1, April 2013
Pages:
1-19
Abstract: Transmission lines are designed to transfer electric power from source locations to distribution networks. This project investigates the problem of fault localization using traveling wave voltage and current signals obtained at a single end of a transmission line and multi ends of a transmission network. Fourier transform (FT) is the most popular transformation that can be applied to traveling wave signals to obtain their frequency components appearing in the fault signal. The wavelet multi resolution analysis is a new and powerful method of signal analysis and is well suited to traveling wave signals. Wavelets can provide multiple resolutions in both time and frequency domains.
Abstract: Transmission lines are designed to transfer electric power from source locations to distribution networks. This project investigates the problem of fault localization using traveling wave voltage and current signals obtained at a single end of a transmission line and multi ends of a transmission network. Fourier transform (FT) is the most popular t...
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Single Layer Printed Reflectarrays at MM-Waves
J. Lanteri,
J. Y. Dauvignac,
Ch. Pichot,
C. Migliaccio
Issue:
Volume 1, Issue 1, April 2013
Pages:
20-28
Abstract: This paper talks about a method of conception and design constraints on mm-wave reflectarrays. The developed tool allows us to plan quickly the behavior of large reflectarray (several tens of wavelength) according to parameters as illumination law or manufacturing tolerance with good agreement with measurements. An ultra-low side-lobe reflectarrays of 130 mm diameter is designed. The structure combines the advantages of a reflectarray with an offset source and those of a specific primary source, exhibiting a prolate radiation pattern, having very low side lobe levels. The maximum gain obtained at 94 GHz is 40 dBi and the side-lobe level is inferior to -28 dB. Finally, a simultaneous multi-lobe antenna is designed at 94 GHz. The primary source is an open-ended waveguide and the phase profile is calculated by the program introduced in the first part. In this case, the four main lobes are placed in the same plane and for equal to -30, -10, 10, 30°. This reflectarray can be used for actual and future generations of automotive radar. The first obtained results are encouraging and show the validity of the concept. Solution retained here is a low-cost solution. The proposed structures are developed on a single layer substrate and fabricated using standard photolithographic techniques. The aim of this article is to show that we can obtain interesting results with relatively simple and low-cost solutions, but also to show the limits of these type of solutions.
Abstract: This paper talks about a method of conception and design constraints on mm-wave reflectarrays. The developed tool allows us to plan quickly the behavior of large reflectarray (several tens of wavelength) according to parameters as illumination law or manufacturing tolerance with good agreement with measurements. An ultra-low side-lobe reflectarrays...
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An Effective Simulation Technique to Evaluate Loss of Load Expectation
Nahid-Al- Masood,
Md. Khurram Monir Rabby,
Mamun Rabbani,
Mafruha Ahmed,
Proteeti Peya
Issue:
Volume 1, Issue 1, April 2013
Pages:
29-34
Abstract: Risk index of loss-of-load expectation is traditionally used to determine generation adequacy. However, be-cause responsibility of generation installation and demand increases with different entities, both generation and load need to be examined to evaluate the resource adequacy of today’s deregulated power systems. An electric utility’s main concern is to plan, design, operate and maintain its power supply to provide an acceptable level of reliability to its users. This clearly requires that standards of reliability be specified and used in all three sectors of the power system, i.e., generation, transmission and distribution. Reliability indices have been defined for the three sectors separately as well as for the bulk power system. Reliability criteria may be determined at the selected load points in the system for different combination of generators and transmission line failures. This paper presents an effective simulation method for the reliability assessment of reliability index, loss-of-load expectation (LOLE). This method is applied to Bangladesh Power System (BPS). BPS has a total installed capacity of around 6550 MW. The maximum demand of BPS is about 5700 MW. The relevant data of the generators and hourly load profiles are collected from the National Load Dispatch Center (NLDC) of Bangladesh and reliability index ‘LOLE’ is assessed for the last six years.
Abstract: Risk index of loss-of-load expectation is traditionally used to determine generation adequacy. However, be-cause responsibility of generation installation and demand increases with different entities, both generation and load need to be examined to evaluate the resource adequacy of today’s deregulated power systems. An electric utility’s main conce...
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RFID Radio Channel Performance Analysis
Salvador Ricardo Meneses González,
Roberto Linares y Miranda
Issue:
Volume 1, Issue 1, April 2013
Pages:
35-40
Received:
20 March 2013
Published:
20 May 2013
Abstract: RFID applied to vehicular identification operates under a complex electromagnetic environment; the radio waves emitted by the reader, propagate, attenuate and join to the reflected waves from the ground and adjacent vehicles, being received by the antenna tag; part of the electromagnetic wave signal is backscattered/reflected back to the reader. In order to obtain a propagation model is carried a deterministic and statistical radio channel analysis out, in such a way that the signal performance could be predictable in an outdoor environment. RFID radio channel multipath environment analysis is the focus of this work
Abstract: RFID applied to vehicular identification operates under a complex electromagnetic environment; the radio waves emitted by the reader, propagate, attenuate and join to the reflected waves from the ground and adjacent vehicles, being received by the antenna tag; part of the electromagnetic wave signal is backscattered/reflected back to the reader. In...
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