Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)s...Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)scenario due to the fast development of in-home PLC.The aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line channel.The MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background noise.We first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,China.Based on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM transmission.According to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate performance.Finally,the link-level performance for both spatial multiplexing and spatial diversity are evaluated.Numeral results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.展开更多
We investigated collisions with power lines by Black-necked Cranes (Grus nigricollis) and Barheaded Geese (Anser indicus) along the Yarlung Tsangpo River in the Tibet Autonomous Region during two winters.Three segment...We investigated collisions with power lines by Black-necked Cranes (Grus nigricollis) and Barheaded Geese (Anser indicus) along the Yarlung Tsangpo River in the Tibet Autonomous Region during two winters.Three segments of a 35 kV transmission line were surveyed each winter for injured and dead birds.Injured birds disappeared within five days of their initial detection; most dead birds encountered had been scavenged.We recorded two dead geese on transects and two injured geese and two dead cranes adjacent to transects.We found a higher incidence of bird strikes along power line segments close to roosting and foraging areas.We recommend that power lines,new or old,located in the flight path from nocturnal roosts,near important foraging areas or crossing the mouths of important agricultural valleys should be marked with colored and/or reflecting devices that have been proven to reduce crane and goose collisions.展开更多
Adaptive bit-loading is a key technology in high speed power line communications with the Orthogonal Frequency Division Multiplexing (OFDM) modulation technology. According to the real situation of the transmitting po...Adaptive bit-loading is a key technology in high speed power line communications with the Orthogonal Frequency Division Multiplexing (OFDM) modulation technology. According to the real situation of the transmitting power spectrum limited in high speed power line communications, this paper explored the adaptive bit loading algorithm to maximize transmission bit number when transmitting power spectral density and bit error rate are not exceed upper limit. With the characteristics of the power line channel, first of all, it obtains the optimal bit loading algorithm, and then provides the improved algorithm to reduce the computational complexity. Based on the analysis and simulation, it offers a non-iterative bit allocation algorithm, and finally the simulation shows that this new algorithm can greatly reduce the computational complexity, and the actual bit allocation results close to optimal.展开更多
Theoretical model and solutions on power line harmonic radiation （PLHR） propagating in the ground, air, and anisotropic homogeneous ionosphere are presented, The theoretical model is verified by the PLHR events obse...Theoretical model and solutions on power line harmonic radiation （PLHR） propagating in the ground, air, and anisotropic homogeneous ionosphere are presented, The theoretical model is verified by the PLHR events observed by the DEMETER satellite. Some propagation characteristics of PLHR based on the model are obtained. This paper is bene- ficial to quantitatively interpret the formation mechanism of PLHR phenomenon.展开更多
In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of ne...In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.展开更多
In South Africa, electricity is supplied through thousands-of-kilometers of overhead power cables, which is owned by Eskom the national energy supplier. Currently monitoring of these overhead power cables are done by ...In South Africa, electricity is supplied through thousands-of-kilometers of overhead power cables, which is owned by Eskom the national energy supplier. Currently monitoring of these overhead power cables are done by means of helicopter inspection flights and foot patrols, which are infrequent and expensive. In this paper, the authors present the design of a prototype power line crawler （inspection robot） for the monitoring of these overhead power lines in South Africa. The designed prototype power line crawler is capable of driving on the wire, balancing on the wire and is capable of maneuvering past certain obstacles found on the overhead power cables. The prototype power line crawler is designed to host a monitoring system that monitors the power line as the inspection robot drives on it. Various experimental tests were performed and are presented in this paper, showing the capability of performing these tasks. This prototype inspection robot ensures a platform for future development in this area.展开更多
In power systems, a large number of OPLs （overhead power lines） are more than 40 years old and some even exceed 50 years old. The key issue for power systems managers, public utilities companies and electrical engin...In power systems, a large number of OPLs （overhead power lines） are more than 40 years old and some even exceed 50 years old. The key issue for power systems managers, public utilities companies and electrical engineers today concerns the manner in which available financial resources should be invested in these OPLs to provide the greatest impact on the power system as a whole and to address the OPLs that require urgent revitalization. This paper presents the application of the software tool RevOPL, developed using Microsoft Access utilizing the ＂methodology for revitalization of high-voltage OPLs＂. The aim is to present both the methodology and software to objectively evaluate the condition of an OPL and determine its remaining service life. The application of this software tool provides a proposal for the scheduling and scope of planned revitalization activities, which are obtained through the optimization of the technical characteristics while remaining within the available budget.展开更多
Insulator defect detection plays a vital role in maintaining the secure operation of power systems.To address the issues of the difficulty of detecting small objects and missing objects due to the small scale,variable...Insulator defect detection plays a vital role in maintaining the secure operation of power systems.To address the issues of the difficulty of detecting small objects and missing objects due to the small scale,variable scale,and fuzzy edge morphology of insulator defects,we construct an insulator dataset with 1600 samples containing flashovers and breakages.Then a simple and effective surface defect detection method of power line insulators for difficult small objects is proposed.Firstly,a high-resolution featuremap is introduced and a small object prediction layer is added so that the model can detect tiny objects.Secondly,a simplified adaptive spatial feature fusion(SASFF)module is introduced to perform cross-scale spatial fusion to improve adaptability to variable multi-scale features.Finally,we propose an enhanced deformable attention mechanism(EDAM)module.By integrating a gating activation function,the model is further inspired to learn a small number of critical sampling points near reference points.And the module can improve the perception of object morphology.The experimental results indicate that concerning the dataset of flashover and breakage defects,this method improves the performance of YOLOv5,YOLOv7,and YOLOv8.In practical application,it can simply and effectively improve the precision of power line insulator defect detection and reduce missing detection for difficult small objects.展开更多
Most existing media access control(MAC) protocols in power line communication(PLC) networks just discard the colliding data packets when collision occurs.The collision deteriorates throughput and delay performance of ...Most existing media access control(MAC) protocols in power line communication(PLC) networks just discard the colliding data packets when collision occurs.The collision deteriorates throughput and delay performance of system under high traffic conditions.This article presents a novel media access scheme with fast collision resolution for in-home power line networks.It works by first recognizing the colliding stations through detecting the inserted unique ID sequence ahead of data packets,then the source nodes retransmitting their packets immediately after the collision slot.The proposed protocol maintains the benefits of ALOHA systems.It needs no scheduling overhead and is suitable for bursty sources,such as multimedia data packets.Computer simulations have demonstrated that this approach can achieve high throughput due to its ability of resolving collisions.展开更多
Background:Electrocution and collisions on power lines are among the leading causes of non-natural mortality for birds.Power lines are exponentially increasing,particularly in developing countries,but mitigation strat...Background:Electrocution and collisions on power lines are among the leading causes of non-natural mortality for birds.Power lines are exponentially increasing,particularly in developing countries,but mitigation strategies to prevent bird mortality are questionable.Mongolia combines a recently increased power line network,an abundant raptor population,a dangerous crossarm configuration and a habitat with no natural perches,producing many bird-power line interactions.Our aim is to assess the bird mortality caused by power lines in the Gobi Desert of Mongolia,to determine the factors increasing the risk of bird electrocution,and to evaluate the effectiveness of used retrofitting measures.Methods:In July 2019 we covered 132.9 km of 15 kV power lines checking 1092 poles.We also conducted bird tran-sects to record raptor and corvid richness and abundance,to assess species vulnerability to electrocution.Results:We recorded 76 electrocuted birds of 7 species.Electrocution rate was 6.96 birds/100 poles.The most affected species were Common Raven(Corvus corax)and Upland Buzzard(Buteo hemilasius),highlighting the electro-cution of 5 endangered Saker Falcons(Falco cherrug).By contrast,we only recorded 8 individuals of 5 species collid-ing with wires,the most affected being Pallas’s Sandgrouse(Syrrhaptes paradoxus).About 76.1%of sampled poles had some mitigation measure.Of these,96.6%were brush perch deflectors and 3.4%rotating-mirrors perch deter-rents.We found differences in electrocution rates among crossarm configurations,with the strain insulator with one jumper being the most lethal.Additionally,we found no correlation between bird abundance and electrocution rates,suggesting that some species are more sensitive to electrocution.Although no differences in total bird electrocu-tion rates were detected between poles with and without perch deterrents,when bird size is considered,deterrents reduced the mortality rate of small birds,while they were ineffective for medium-sized birds.Conclusions:Despite the widespread use of perch deterrents in the Mongolian power line network,there is still an alarming electrocution rate.This strategy is ineffective and some mechanisms,such as brush perch deflectors,may increase the electrocution rate for some medium-sized birds.Finally,we propose strategies to minimize the avian electrocution rate in the Gobi Desert.展开更多
This letter derives the Equivalent M-band Discrete Wavelet(EMDW) transmission mode of Orthogonal Frequency Division Multiplexing(OFDM) transmission systems, and presents a new Quadrature M-band Discrete Wavelet(QMDW) ...This letter derives the Equivalent M-band Discrete Wavelet(EMDW) transmission mode of Orthogonal Frequency Division Multiplexing(OFDM) transmission systems, and presents a new Quadrature M-band Discrete Wavelet(QMDW) based OFDM-CDMA(Code Division Multiple Access) communication systems for high speed Power Line Communication (PLC) channels.This system gives much better robustness to Inter-Channel Interference (ICI), Multi-User Interference (MUI) and noise interference, which is verified by simulation.展开更多
When solving the routing problem with traditional ant colony algorithm, there is scarce in initialize pheromone and a slow convergence and stagnation for the complex network topology and the time-varying characteristi...When solving the routing problem with traditional ant colony algorithm, there is scarce in initialize pheromone and a slow convergence and stagnation for the complex network topology and the time-varying characteristics of channel in power line carrier communication of low voltage distribution grid. The algorithm is easy to fall into premature and local optimization. Proposed an automatic network algorithm based on improved transmission delay and the load factor as the evaluation factors. With the requirements of QoS, a logical topology of power line communication network is established. By the experiment of MATLAB simulation, verify that the improved Dynamic hybrid ant colony genetic algorithm (DH_ACGA) algorithm has improved the communication performance, which solved the QoS routing problems of power communication to some extent.展开更多
Power line is an efficient media for home area networking communication scenarios. However, it is not designed to transmit data. This causes several perturbations phenomenon for communications technologies over the po...Power line is an efficient media for home area networking communication scenarios. However, it is not designed to transmit data. This causes several perturbations phenomenon for communications technologies over the power cables. This work presents an investigation of the indoor narrowband power lines channel behavior. The load, the transmission line length and the network topology impact are studied using a simple network. A channel response measure campaign has been realized in 13 sites. The channel capacity has been used for channel classification. The measures were classified into 5 classes. It is shown that channel response is mainly impacted by the load impedance. The class distributions are more impacted by the nature of appliances connected into the indoor network.展开更多
This paper presents the basic principle of OFDM technology and some key technologies, and do the simulation of OFDM technology. Secondly, on the basis of the design of intelligent Home Furnishing system demand, this p...This paper presents the basic principle of OFDM technology and some key technologies, and do the simulation of OFDM technology. Secondly, on the basis of the design of intelligent Home Furnishing system demand, this paper research and design low voltage power line carrier communication based on Intelligent Home Furnishing system for. The circuit takes ARM Cortex-M3 based on the ARM kernel as the central controller, and realize remote monitoring and control of equipment through the transplantation of uC/OS-II system and the design of Web Serve program. Using OFDM power line carrier communication modes as networking mode of the intelligent Home Furnishing system. Finally, the paper realize the intelligent node and relevant software that constitute a complete system of intelligent Home Furnishing.展开更多
This is an extended version of the same titled paper presented at the 21st CIRED. It discusses a new technique for identification and location of defective insulator strings in power lines based on the analysis of hig...This is an extended version of the same titled paper presented at the 21st CIRED. It discusses a new technique for identification and location of defective insulator strings in power lines based on the analysis of high frequency signals generated by corona effect. Damaged insulator strings may lead to loss of insulation and hence to the corona effect, in other words, to partial discharges. These partial discharges can be detected by a system composed of a capacitive coupling device （region between the phase and the metal body of a current transformer）, a data acquisition board and a computer. Analyzing the waveform of these partial discharges through a neural network based software, it is possible to identify and locate the defective insulator string. This paper discusses how this software analysis works and why its technique is suitable for this application. Hence the results of key tests performed along the development are discussed, pointing out the main factors that affect their performance.展开更多
Power line communication technology is used in various applications, from high voltage network to the low voltage network, as it is the only wired communication technology that is comparable with wireless communicatio...Power line communication technology is used in various applications, from high voltage network to the low voltage network, as it is the only wired communication technology that is comparable with wireless communication network. It works by injecting a modulated carrier wave into the electric cables from one transceiver to another. But still, the noise level and impedance mismatch are still the main concern of this technology, particularly in the low voltage network in residential area. Power line has additive non-white noise and extremely harsh environment for communication. At the same time, there is signal attenuation along the power line caused by the impedance mismatch in the power line network. Even though these problems can be controlled using a band-pass filter and an impedance matching circuit respectively, but the impedances in the power line are time and location variant and it is rather difficult to design a circuit that allows maximum power transfer in the system all the time. Thus in this paper, a new adaptive impedance matching circuits is proposed for narrowband power line communication. This methodology is derived based on the RLC band-pass filter circuit. This concept is designed to achieve simpler configuration and higher matching resolution.展开更多
With the rapid development of the electric power industry, the traditional "two meters" electric power testing mode has been unable to meet its development needs, and the combination of GPRS technology and e...With the rapid development of the electric power industry, the traditional "two meters" electric power testing mode has been unable to meet its development needs, and the combination of GPRS technology and electric power testing work has brought convenience to the power supply work. This document introduces the advantages and structure of the real-time intelligent power patrol system based on GPRS technology, hoping to provide a reference for the future work. In recent years, with the development of science and technology, peoples demand for electricity is constantly increasing, and the intelligent safety of power lines is the basic premise of power demand. However, in the process of operation, various factors will lead to the power line failure and damage, the need for the power line maintenance personnel to ensure the normal operation of the power at the same time, the maintenance and inspection of the power line. Therefore, the operation of high-altitude transmission line is one of the important tasks of electric power maintenance personnel today. This white paper focuses on the intelligent safety protection of UHV power lines operating at high altitude. This paper will discuss the intelligent safety belt of power line aerial operation based on GPRS communication technology.展开更多
Significant investments have been made regarding the construction of a great number of high-voltage overhead power lines of all voltage levels, and now the questions arise on where and how to direct the investments ne...Significant investments have been made regarding the construction of a great number of high-voltage overhead power lines of all voltage levels, and now the questions arise on where and how to direct the investments necessary for the maintenance of overhead power lines. To organise the process of maintenance of overhead power lines correctly, it is necessary to have the current information on the condition of particular components of a line. In this paper, special attention has been paid to the real condition of overhead power lines, with the aim of making the decision whether some of the following measures are necessary, and to what extent： the revitalisation for a certain number of years is perceived, the revitalisation up to five years and reconstruction of the overhead power line is performed, its restoration is performed or nothing is done. The approach to the perceiving of real condition of high-voltage overhead power lines is presented on a global block diagram. With the aim of setting out the list of priorities for revitalisation, the criteria have been defined with regards to the real condition of particular components of an overhead power line, as well as pursuant to the role and importance in an electric power system. The correctly defined criteria contribute to the solving of the problem of making a single list of priorities for the revitalisation of high-voltage overhead power lines. In that way, the recommendations are being given to the transmission companies, to achieve a higher reliability of an electric power system, with a minimum number of cancellations and a maximum extension of working life of all the components of overhead power lines. A correct maintenance of overhead power lines brings large financial savings to the owners of transmission companies, and that is the primary goal in a deregulated environment.展开更多
Power line inspection is an essential procedure in the power lines maintenance area, especially thinking about service availability and energy efficiency. Aerial inspection of electric power transmission lines is typi...Power line inspection is an essential procedure in the power lines maintenance area, especially thinking about service availability and energy efficiency. Aerial inspection of electric power transmission lines is typically performed using human-piloted helicopters, which is a procedure that is both expensive and prone to accidents taking risks to human beings＇ lives. The work presents a solution based on UAS （unmanned aircraft system） for inspecting power lines. In this context a R ＆ D project of an unmanned aircraft system to be used for performing complete aerial inspection of overhead power lines is being executed by ITA （Instituto Tecnol6gico de Aeron^utica） （Technological Institute of Aeronautics） in Brazil. Special attention is dedicated to the communication system conception in order to comply with Remotely Piloted Aircraft System definition in the context of long endurance operations of the system. It presents a solution based on LTA （lighter than air） platform in order to extend the communication range beyond line of sight.展开更多
With the development of China's society, the development of power line engineering is also accelerating, and its application scope is more extensive. It also gradually involves many fields. With the update and ite...With the development of China's society, the development of power line engineering is also accelerating, and its application scope is more extensive. It also gradually involves many fields. With the update and iteration of related technologies, many problems are constantly exposed, especially safety management. In the process of electric power construction, enterprises must strengthen the management of electric power line construction to ensure the smooth development of the whole electric power project. In this paper, the problems existing in power line construction and the related contents of safety management countermeasures are discussed, hoping to provide some effective references.展开更多
文摘Power line communication(PLC)provides intelligent electrical functions such as power quality measurement,fault surveys,and remote control of electrical network.Most of research works have been done in low voltage(LV)scenario due to the fast development of in-home PLC.The aim of this paper is to evaluate the link-level performance of a medium voltage(MV)MIMO-OFDM communication system based on transmission link under underground power line channel.The MIMO channel is modeled as a modified multipath model in the presence of impulsive noise and background noise.We first perform a measurement on the practical MV MIMO channel parameters for a section of buried cable of 1 km long in Ganzhou city,Jiangxi province,China.Based on the measured channel,we design the frame structure based on an IEEE standard for broadband over power line networks[1]to support MV MIMO-OFDM transmission.According to designed frame structure,we design an encoder and a decoder for a dual binary tail-biting turbo code and optimize some key decoder parameters for low bit error rate performance.Finally,the link-level performance for both spatial multiplexing and spatial diversity are evaluated.Numeral results show that MV MIMO-OFDM is a promising approach to provide both high data rate and link reliability for PLC.
基金support was provided by the Continental Minerals Corporation
文摘We investigated collisions with power lines by Black-necked Cranes (Grus nigricollis) and Barheaded Geese (Anser indicus) along the Yarlung Tsangpo River in the Tibet Autonomous Region during two winters.Three segments of a 35 kV transmission line were surveyed each winter for injured and dead birds.Injured birds disappeared within five days of their initial detection; most dead birds encountered had been scavenged.We recorded two dead geese on transects and two injured geese and two dead cranes adjacent to transects.We found a higher incidence of bird strikes along power line segments close to roosting and foraging areas.We recommend that power lines,new or old,located in the flight path from nocturnal roosts,near important foraging areas or crossing the mouths of important agricultural valleys should be marked with colored and/or reflecting devices that have been proven to reduce crane and goose collisions.
基金Supported by the National Natural Science Foundation Project (No. 60872073, No. 60975017, and No. 51075068)Doctoral Fund of Education Ministry (No. 2011009213-0004)
文摘Adaptive bit-loading is a key technology in high speed power line communications with the Orthogonal Frequency Division Multiplexing (OFDM) modulation technology. According to the real situation of the transmitting power spectrum limited in high speed power line communications, this paper explored the adaptive bit loading algorithm to maximize transmission bit number when transmitting power spectral density and bit error rate are not exceed upper limit. With the characteristics of the power line channel, first of all, it obtains the optimal bit loading algorithm, and then provides the improved algorithm to reduce the computational complexity. Based on the analysis and simulation, it offers a non-iterative bit allocation algorithm, and finally the simulation shows that this new algorithm can greatly reduce the computational complexity, and the actual bit allocation results close to optimal.
基金Project supported by the National Natural Science Foundation of China(Grant No.51207006)the Natural Science Foundation of Beijing,China(Grant No.3123038)
文摘Theoretical model and solutions on power line harmonic radiation （PLHR） propagating in the ground, air, and anisotropic homogeneous ionosphere are presented, The theoretical model is verified by the PLHR events observed by the DEMETER satellite. Some propagation characteristics of PLHR based on the model are obtained. This paper is bene- ficial to quantitatively interpret the formation mechanism of PLHR phenomenon.
文摘In the past decade,several efforts around the world were started with the goal of introducing "smart metering" capabilities into the power grid.These efforts have spurred renewed interest in the design of next generation Narrowband Power Line Communications(NB-PLC) transceivers.In the past few years,ITU-T and IEEE have standardized a family of next generation OFDM-based NB-PLC transceivers some of which are today being considered for massive deployments in Europe and Asia.This paper addresses the important role that PLC has not only for smart metering but also for many other Smart Grid applications,and also gives an overview of the main differences between these next generation NB-PLC standards.
文摘In South Africa, electricity is supplied through thousands-of-kilometers of overhead power cables, which is owned by Eskom the national energy supplier. Currently monitoring of these overhead power cables are done by means of helicopter inspection flights and foot patrols, which are infrequent and expensive. In this paper, the authors present the design of a prototype power line crawler （inspection robot） for the monitoring of these overhead power lines in South Africa. The designed prototype power line crawler is capable of driving on the wire, balancing on the wire and is capable of maneuvering past certain obstacles found on the overhead power cables. The prototype power line crawler is designed to host a monitoring system that monitors the power line as the inspection robot drives on it. Various experimental tests were performed and are presented in this paper, showing the capability of performing these tasks. This prototype inspection robot ensures a platform for future development in this area.
文摘In power systems, a large number of OPLs （overhead power lines） are more than 40 years old and some even exceed 50 years old. The key issue for power systems managers, public utilities companies and electrical engineers today concerns the manner in which available financial resources should be invested in these OPLs to provide the greatest impact on the power system as a whole and to address the OPLs that require urgent revitalization. This paper presents the application of the software tool RevOPL, developed using Microsoft Access utilizing the ＂methodology for revitalization of high-voltage OPLs＂. The aim is to present both the methodology and software to objectively evaluate the condition of an OPL and determine its remaining service life. The application of this software tool provides a proposal for the scheduling and scope of planned revitalization activities, which are obtained through the optimization of the technical characteristics while remaining within the available budget.
基金State Grid Jiangsu Electric Power Co.,Ltd.of the Science and Technology Project(Grant No.J2022004).
文摘Insulator defect detection plays a vital role in maintaining the secure operation of power systems.To address the issues of the difficulty of detecting small objects and missing objects due to the small scale,variable scale,and fuzzy edge morphology of insulator defects,we construct an insulator dataset with 1600 samples containing flashovers and breakages.Then a simple and effective surface defect detection method of power line insulators for difficult small objects is proposed.Firstly,a high-resolution featuremap is introduced and a small object prediction layer is added so that the model can detect tiny objects.Secondly,a simplified adaptive spatial feature fusion(SASFF)module is introduced to perform cross-scale spatial fusion to improve adaptability to variable multi-scale features.Finally,we propose an enhanced deformable attention mechanism(EDAM)module.By integrating a gating activation function,the model is further inspired to learn a small number of critical sampling points near reference points.And the module can improve the perception of object morphology.The experimental results indicate that concerning the dataset of flashover and breakage defects,this method improves the performance of YOLOv5,YOLOv7,and YOLOv8.In practical application,it can simply and effectively improve the precision of power line insulator defect detection and reduce missing detection for difficult small objects.
文摘Most existing media access control(MAC) protocols in power line communication(PLC) networks just discard the colliding data packets when collision occurs.The collision deteriorates throughput and delay performance of system under high traffic conditions.This article presents a novel media access scheme with fast collision resolution for in-home power line networks.It works by first recognizing the colliding stations through detecting the inserted unique ID sequence ahead of data packets,then the source nodes retransmitting their packets immediately after the collision slot.The proposed protocol maintains the benefits of ALOHA systems.It needs no scheduling overhead and is suitable for bursty sources,such as multimedia data packets.Computer simulations have demonstrated that this approach can achieve high throughput due to its ability of resolving collisions.
基金supported by Generalitat Valenciana(SEJI/2018/024).JMPGESG were supported by Spanish Ministry of Science,Innovation and Universities contracts(IJC-2019-038968 and RYC-2019-027216-I),ZMRLNA by contracts cofunded by the Generalitat Valenciana and the European Social Fund(APOSTD/2019/016 and ACIF/2019/056,respectively).
文摘Background:Electrocution and collisions on power lines are among the leading causes of non-natural mortality for birds.Power lines are exponentially increasing,particularly in developing countries,but mitigation strategies to prevent bird mortality are questionable.Mongolia combines a recently increased power line network,an abundant raptor population,a dangerous crossarm configuration and a habitat with no natural perches,producing many bird-power line interactions.Our aim is to assess the bird mortality caused by power lines in the Gobi Desert of Mongolia,to determine the factors increasing the risk of bird electrocution,and to evaluate the effectiveness of used retrofitting measures.Methods:In July 2019 we covered 132.9 km of 15 kV power lines checking 1092 poles.We also conducted bird tran-sects to record raptor and corvid richness and abundance,to assess species vulnerability to electrocution.Results:We recorded 76 electrocuted birds of 7 species.Electrocution rate was 6.96 birds/100 poles.The most affected species were Common Raven(Corvus corax)and Upland Buzzard(Buteo hemilasius),highlighting the electro-cution of 5 endangered Saker Falcons(Falco cherrug).By contrast,we only recorded 8 individuals of 5 species collid-ing with wires,the most affected being Pallas’s Sandgrouse(Syrrhaptes paradoxus).About 76.1%of sampled poles had some mitigation measure.Of these,96.6%were brush perch deflectors and 3.4%rotating-mirrors perch deter-rents.We found differences in electrocution rates among crossarm configurations,with the strain insulator with one jumper being the most lethal.Additionally,we found no correlation between bird abundance and electrocution rates,suggesting that some species are more sensitive to electrocution.Although no differences in total bird electrocu-tion rates were detected between poles with and without perch deterrents,when bird size is considered,deterrents reduced the mortality rate of small birds,while they were ineffective for medium-sized birds.Conclusions:Despite the widespread use of perch deterrents in the Mongolian power line network,there is still an alarming electrocution rate.This strategy is ineffective and some mechanisms,such as brush perch deflectors,may increase the electrocution rate for some medium-sized birds.Finally,we propose strategies to minimize the avian electrocution rate in the Gobi Desert.
基金the National Natural Science Foundation of China(No.60072048)
文摘This letter derives the Equivalent M-band Discrete Wavelet(EMDW) transmission mode of Orthogonal Frequency Division Multiplexing(OFDM) transmission systems, and presents a new Quadrature M-band Discrete Wavelet(QMDW) based OFDM-CDMA(Code Division Multiple Access) communication systems for high speed Power Line Communication (PLC) channels.This system gives much better robustness to Inter-Channel Interference (ICI), Multi-User Interference (MUI) and noise interference, which is verified by simulation.
文摘When solving the routing problem with traditional ant colony algorithm, there is scarce in initialize pheromone and a slow convergence and stagnation for the complex network topology and the time-varying characteristics of channel in power line carrier communication of low voltage distribution grid. The algorithm is easy to fall into premature and local optimization. Proposed an automatic network algorithm based on improved transmission delay and the load factor as the evaluation factors. With the requirements of QoS, a logical topology of power line communication network is established. By the experiment of MATLAB simulation, verify that the improved Dynamic hybrid ant colony genetic algorithm (DH_ACGA) algorithm has improved the communication performance, which solved the QoS routing problems of power communication to some extent.
文摘Power line is an efficient media for home area networking communication scenarios. However, it is not designed to transmit data. This causes several perturbations phenomenon for communications technologies over the power cables. This work presents an investigation of the indoor narrowband power lines channel behavior. The load, the transmission line length and the network topology impact are studied using a simple network. A channel response measure campaign has been realized in 13 sites. The channel capacity has been used for channel classification. The measures were classified into 5 classes. It is shown that channel response is mainly impacted by the load impedance. The class distributions are more impacted by the nature of appliances connected into the indoor network.
文摘This paper presents the basic principle of OFDM technology and some key technologies, and do the simulation of OFDM technology. Secondly, on the basis of the design of intelligent Home Furnishing system demand, this paper research and design low voltage power line carrier communication based on Intelligent Home Furnishing system for. The circuit takes ARM Cortex-M3 based on the ARM kernel as the central controller, and realize remote monitoring and control of equipment through the transplantation of uC/OS-II system and the design of Web Serve program. Using OFDM power line carrier communication modes as networking mode of the intelligent Home Furnishing system. Finally, the paper realize the intelligent node and relevant software that constitute a complete system of intelligent Home Furnishing.
文摘This is an extended version of the same titled paper presented at the 21st CIRED. It discusses a new technique for identification and location of defective insulator strings in power lines based on the analysis of high frequency signals generated by corona effect. Damaged insulator strings may lead to loss of insulation and hence to the corona effect, in other words, to partial discharges. These partial discharges can be detected by a system composed of a capacitive coupling device （region between the phase and the metal body of a current transformer）, a data acquisition board and a computer. Analyzing the waveform of these partial discharges through a neural network based software, it is possible to identify and locate the defective insulator string. This paper discusses how this software analysis works and why its technique is suitable for this application. Hence the results of key tests performed along the development are discussed, pointing out the main factors that affect their performance.
文摘Power line communication technology is used in various applications, from high voltage network to the low voltage network, as it is the only wired communication technology that is comparable with wireless communication network. It works by injecting a modulated carrier wave into the electric cables from one transceiver to another. But still, the noise level and impedance mismatch are still the main concern of this technology, particularly in the low voltage network in residential area. Power line has additive non-white noise and extremely harsh environment for communication. At the same time, there is signal attenuation along the power line caused by the impedance mismatch in the power line network. Even though these problems can be controlled using a band-pass filter and an impedance matching circuit respectively, but the impedances in the power line are time and location variant and it is rather difficult to design a circuit that allows maximum power transfer in the system all the time. Thus in this paper, a new adaptive impedance matching circuits is proposed for narrowband power line communication. This methodology is derived based on the RLC band-pass filter circuit. This concept is designed to achieve simpler configuration and higher matching resolution.
文摘With the rapid development of the electric power industry, the traditional "two meters" electric power testing mode has been unable to meet its development needs, and the combination of GPRS technology and electric power testing work has brought convenience to the power supply work. This document introduces the advantages and structure of the real-time intelligent power patrol system based on GPRS technology, hoping to provide a reference for the future work. In recent years, with the development of science and technology, peoples demand for electricity is constantly increasing, and the intelligent safety of power lines is the basic premise of power demand. However, in the process of operation, various factors will lead to the power line failure and damage, the need for the power line maintenance personnel to ensure the normal operation of the power at the same time, the maintenance and inspection of the power line. Therefore, the operation of high-altitude transmission line is one of the important tasks of electric power maintenance personnel today. This white paper focuses on the intelligent safety protection of UHV power lines operating at high altitude. This paper will discuss the intelligent safety belt of power line aerial operation based on GPRS communication technology.
文摘Significant investments have been made regarding the construction of a great number of high-voltage overhead power lines of all voltage levels, and now the questions arise on where and how to direct the investments necessary for the maintenance of overhead power lines. To organise the process of maintenance of overhead power lines correctly, it is necessary to have the current information on the condition of particular components of a line. In this paper, special attention has been paid to the real condition of overhead power lines, with the aim of making the decision whether some of the following measures are necessary, and to what extent： the revitalisation for a certain number of years is perceived, the revitalisation up to five years and reconstruction of the overhead power line is performed, its restoration is performed or nothing is done. The approach to the perceiving of real condition of high-voltage overhead power lines is presented on a global block diagram. With the aim of setting out the list of priorities for revitalisation, the criteria have been defined with regards to the real condition of particular components of an overhead power line, as well as pursuant to the role and importance in an electric power system. The correctly defined criteria contribute to the solving of the problem of making a single list of priorities for the revitalisation of high-voltage overhead power lines. In that way, the recommendations are being given to the transmission companies, to achieve a higher reliability of an electric power system, with a minimum number of cancellations and a maximum extension of working life of all the components of overhead power lines. A correct maintenance of overhead power lines brings large financial savings to the owners of transmission companies, and that is the primary goal in a deregulated environment.
文摘Power line inspection is an essential procedure in the power lines maintenance area, especially thinking about service availability and energy efficiency. Aerial inspection of electric power transmission lines is typically performed using human-piloted helicopters, which is a procedure that is both expensive and prone to accidents taking risks to human beings＇ lives. The work presents a solution based on UAS （unmanned aircraft system） for inspecting power lines. In this context a R ＆ D project of an unmanned aircraft system to be used for performing complete aerial inspection of overhead power lines is being executed by ITA （Instituto Tecnol6gico de Aeron^utica） （Technological Institute of Aeronautics） in Brazil. Special attention is dedicated to the communication system conception in order to comply with Remotely Piloted Aircraft System definition in the context of long endurance operations of the system. It presents a solution based on LTA （lighter than air） platform in order to extend the communication range beyond line of sight.
文摘With the development of China's society, the development of power line engineering is also accelerating, and its application scope is more extensive. It also gradually involves many fields. With the update and iteration of related technologies, many problems are constantly exposed, especially safety management. In the process of electric power construction, enterprises must strengthen the management of electric power line construction to ensure the smooth development of the whole electric power project. In this paper, the problems existing in power line construction and the related contents of safety management countermeasures are discussed, hoping to provide some effective references.
