scholarly journals Broadband Transmission and Statistical Performance Properties of Overhead High-Voltage Transmission Networks

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Athanasios G. Lazaropoulos

This paper considers broadband signal transmission and statistical performance properties of high-voltage/broadband over power lines (HV/BPL) channels associated with overhead power transmission. The overhead HV/BPL transmission channel is investigated with regard to its spectral behavior, its end-to-end signal attenuation, and its statistical performance metrics. It is found that the above features depend critically on the frequency, the overhead HV power grid type (150 kV, 275 kV, or 400 kV and single- or double-circuit), the coupling scheme applied, the physical properties of the cables used, the MTL configuration, and the type of branches existing along the end-to-end BPL signal propagation. The contribution of this paper is threefold. First, the significant broadband transmission potential of overhead HV lines is revealed. The results demonstrate that, regardless of overhead HV power grid type, the overhead HV grid is a potentially excellent communications medium, offering low-loss characteristics, flat-fading features, and low multipath dispersion over a 25 km repeater span well beyond 100 MHz. Second, regarding the statistical properties of various overhead HV/BPL transmission channels, two fundamental correlations of several wireline systems, for example, coaxial cables and xDSL, are also validated in the case of overhead HV/BPL transmission channels, namely, (i) end-to-end channel attenuation in relation with root-mean-square delay spread (RMS-DS) and (ii) coherence bandwidth (CB) in relation with RMS-DS. Third, fitting the numerical results and other field trial measurements, two regression distributions suitable for each fundamental correlation are proposed.

2012 ◽  
Vol 2012 ◽  
pp. 1-18 ◽  
Author(s):  
Athanasios G. Lazaropoulos

The need of bridging the digital gap between underdeveloped/developed areas and promoting smart grid (SG) networks urges the deployment of broadband over power lines (BPL) systems and their further integration. The contribution of this paper is fourfold. First, based on the well-established hybrid model of (Lazaropoulos and Cottis 2009, 2010, Lazaropoulos, 2012) and the generic multidimensional network analysis tool presented in (Lazaropoulos 2012, Sartenaer 2004, Sartenaer and Delogne 2006, 2001) an exact multidimensional chain scattering matrix method, which is suitable for overhead high-voltage/broadband over power lines (HV/BPL) networks, is proposed and is evaluated against other theoretical and experimental proven models. Second, the proposed method investigates the overhead HV/BPL transmission grids (overhead 150 kV single-circuit, 275 kV double-circuit, and 400 kV double-circuit multiconductor structures) with regard to their end-to-end signal attenuation. It is found that the above features depend drastically on the overhead power grid type, the frequency, the MTL configuration, the physical properties of the cables used, the end-to-end distance, and the number, the length, and the terminations of the branches encountered along the end-to-end BPL signal propagation. Third, the impact of the multiplicity of the branches at the same junction in overhead HV grids is first examined. Based on the inherent long-branch structure and the quasi-static behavior of single/multiple branches with matched terminations of overhead HV grid, a simple approach suitable for overhead HV/BPL channel estimation is presented. Fourth, identifying the similar characteristics among different overhead HV/BPL configurations, an additional step towards the common overhead HV/BPL analysis is demonstrated; the entire overhead HV/BPL grid may be examined under a common PHY framework regardless of the overhead HV/BPL grid type examined. Finally, apart from the presentation of broadband transmission potential of the entire overhead transmission power grid, a consequence of this paper is that it helps towards: (i) the better broadband monitoring and management of overhead HV transmission power grids in an interactive SG network; and (ii) the intraoperability/interoperability of overhead HV/BPL systems under the aegis of a unified transmission/distribution SG power network.


2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Athanasios G. Lazaropoulos

The established statistical analysis, already used to treat overhead transmission power grid networks, is now implemented to examine the factors influencing modal transmission characteristics and modal statistical performance metrics of overhead and underground low-voltage/broadband over power lines (LV/BPL) and medium-voltage/broadband over power lines (MV/BPL) channels associated with power distribution in smart grid (SG) networks. The novelty of this paper is threefold. First, a refined multidimensional chain scattering matrix (TM2) method suitable for overhead and underground LV/BPL and MV/BPL modal channels is evaluated against other relative theoretical and experimental proven models. Second, applying TM2 method, the end-to-end modal channel attenuation of various LV/BPL and MV/BPL multiconductor transmission line (MTL) configurations is determined. The LV/BPL and MV/BPL transmission channels are investigated with regard to their spectral behavior and their end-to-end modal channel attenuation. It is found that the above features depend drastically on the frequency, the type of power grid, the mode considered, the MTL configuration, the physical properties of the cables used, the end-to-end distance, and the number, the electrical length, and the terminations of the branches encountered along the end-to-end BPL signal propagation. Third, the statistical properties of various overhead and underground LV/BPL and MV/BPL modal channels are investigated revealing the correlation between end-to-end modal channel attenuation and modal root-mean-square delay spread (RMS-DS). Already verified in the case of overhead high-voltage (HV) BPL systems, this fundamental property of several wireline systems is also modally validated against relevant sets of field measurements, numerical results, and recently proposed statistical channel models for various overhead and underground LV/BPL and MV/BPL channels. Based on this common inherent attribute of either transmission or distribution BPL networks, new unified regression trend line is proposed giving a further boost towards BPL system intraoperability. A consequence of this paper is that it aids in gaining a better understanding of the range and coverage that BPL solutions can achieve; a preliminary step toward the system symbiosis between BPL systems and other broadband technologies in an SG environment.


2015 ◽  
Vol 713-715 ◽  
pp. 1347-1350
Author(s):  
Yu Fei Rao ◽  
Lin Lin Yu

In the process of China's ultra high-voltage (UHV) construction, Henan UHV power grid is the important part. Summer great load mode of Henan power gird is chosen as the typical method. In the background of completing Nanyang UHV extension project, based on single pole running and double pole running of Hami-Zhengzhou UHVDC project respectively, it is simulated and analyzed. The results indicate that power grid cannot maintain stability when single pole block fault or double pole block fault occurs. Through theoretical analysis and simulation, under UHV AC running certain limit, HVDC latching grid is stable. Under UHV DC running certain limit, HVDC latching grid is stable. Based on continuous simulation, this paper obtained the coordinated operation of area UHV AC and DC.


2016 ◽  
Vol 16 (6) ◽  
pp. 220-231
Author(s):  
Hong Kun Wang ◽  
Shou Xiang Wang ◽  
Jing Nie

Abstract With the formation of China’s large power grid, the security of the network is particularly important. The contaminant flashover of insulators has a serious impact on the operation safety of a high voltage power network. In this paper, the acoustic signals’ characteristics of the contaminant insulators flashover are analyzed, and, as a result, the correlation between the acoustic signal and the contaminant insulator flashover is established. To experiment with contaminant insulator for three different Equivalent Salt Deposit Densities (ESDD), acoustic signals were collected separately. Then, the contaminant insulators’ acoustic signals of flashover were analyzed by wavelet packet. The characteristics of the signals were obtained, and they can be judged for contaminant flashover warning.


Author(s):  
Richard A. Katz ◽  
Azizul H. Quazi

Abstract Sonar signal propagation has been traditionally modeled as a linear stochastic process. This research is a major departure from that classical viewpoint and is aimed at modeling acoustic signal propagation dynamics deterministically using the analysis tools of Nonlinear Dynamics and Chaos Theory. Advantages of using this new paradigm over traditional approaches to sonar modeling are demonstrated by simulating a linear frequency modulated (LFM) active sonar signal and two nonlinear variations of it. When nonlinear performance metrics called the mutual information (MI) and the differential radius (DR) are applied to both linear and nonlinear variants of the LFM signal, both metrics are found to be useful detectors of nonlinearity in a simulated acoustic time series. Next we demonstrate the DR technique, on real ultrasonic time series data, that was found to be useful for the diagnosis and treatment of a heart disease called atrial fibrillation. After summarizing results, we conclude with recommended future directions in applied nonlinear sonar signal propagation research.


Author(s):  
Geetanjali Rathee ◽  
Hemraj Saini

Secure routing is considered as one of a key challenge in mesh networks because of its dynamic and broadcasting nature. The broadcasting nature of mesh environment invites number of security vulnerabilities to come and affect the network metrics drastically. Further, any node/link failure of a routed path may reduce the performance of the entire network. A number of secure routing protocols have been proposed by different researchers but enhancement of a single network parameter (i.e. security) may affect another performance metrics significantly i.e. throughput, end to end delay, packet delivery ratio etc. In order to ensure secure routing with improved network metrics, a Secure Buffer based Routing Protocol i.e. SBRP is proposed which ensures better network performance with increased level of security. SBRP protocol uses buffers at alternate positions to fasten re-routing mechanism during node/link failure and ensures the security using AES encryption. Further the protocol is analyzed against mAODV protocol in both static and dynamic environment in terms of security, packet delivery ratio, end to end delay and network throughput.


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