Power Line Communication Networks Research Articles

Optimal subcarrier pairing scheme for maximal ratio combining in OFDM power line communications

Power line communication (PLC) networks for a smart grid require high reliability for data communications. In order to improve the reliability of PLC networks, we consider a maximal ratio combining (MRC) diversity scheme for a power line orthogonal frequency division multiplexing (OFDM) system. An optimal subcarrier pairing scheme is proposed to maximize the MRC gain. Numerical results are presented to verify that the proposed scheme provides enhanced performance.

Influence of the channel instability on the PLC QoS

Intensive rollout of smart grids (SG) creates a special demand on communication networks. Especially, they have to supply sufficient quality of service (QoS) to a big number of customers. Therefore the required QoS becomes more demanding (e.g., minimum throughput have to be increased) and in meantime the cost of the network installation and management should be reduced. Power line communication (PLC) becomes a challenging technology inside SGs. It uses already available power cables and therefore reduces the installation costs of the network. In particular, the usage of PLC is beneficial for power utilities, which appear to be the owners of this communication medium. Nevertheless, PLC remains an emerging technology. Achievable QoS for particular PLC network scenarios are hard to predict and still need to be studied. It is reasoned by the fact, that the PLC environment (cable structure, electrical devices, etc.) induces special effects on the informational signal propagation over the communication medium. These effects may result in considerable impairments of the PLC signal. Nevertheless, with a usage of a cognitive mechanism a big part of them can be avoided or even taken as an advantage. This paper overviews the influence of the channel instability on the PLC QoS. A data link layer (DLL) of a PLC protocol can implement a channel prediction mechanism, which is beneficial for multiple PLC applications. A short description on this mechanism is also introduced in this paper.

Power Line Communication Performance Channel Characteristics

Power lines form the medium of transmission in PLC systems. The original purpose of these lines is the transportation of electric signals at 50 or 60 Hz .This paper proposes a new channel modeling method for power line communications networks based on the multipath profile in the time domain. The new channel model is developed to be applied in a range of Power line Communications (PLC) research topics such as impulse noise modeling, deployment and coverage studies, and communications theory analysis. The statistical multipath parameters such as path arrival time, magnitude and interval for each category are analyzed to build the model. Each generated channel based on the proposed Power line communication that a performance channel characteristic represents a different realization of a PLC network

AN ALTERNATIVE APPROACH IN POWER LINE COMMUNICATION CHANNEL MODELLING

In this paper, we present the measurement methodology and results for a low voltage Power line Communications (PLC) network under difierent conflgurations. Based on the measurements, a correlation of the channel transfer characteristics to the network topology is established and a deterministic model based on two-wire transmission line theory for transverse electromagnetic (TEM) wave propagation is proposed. The channel frequency response in frequency range of 1{30MHz is determined, where the model results agree well with the measurements. The development of accurate power line communication (PLC) channel transfer characteristics models is important as it forms the basis for computer simulations which are useful in appropriate system design, and further enable the analysis of the performance of difierent network conflgurations and loads (1). There is therefore continued research in the characterization of the power line as a communication medium. Difierent techniques which are based on either measurements or theoretical derivations from physical parameters, denoted as top-down or empirical models (2,3), and bottom-up or deterministic models (4{6), respectively, are employed. The empirical model is easy to use as it calls for little computation and is easy to implement. It is however susceptible to measurement errors and cannot be used to reproduce the channel characteristics of a difierent PLC network. The deterministic model difiers from the latter in that it necessitates detailed knowledge of all components and their respective characteristics. Therefore the network behaviour in relation to the model parameters is clearly deflned, and is considered in this work. True to its original purpose, the low voltage power line network within a typical in-building structure is optimized for the transmission of high voltages at low frequencies contrary to data transmission which necessitates the transmission of low voltage at high frequencies. The communication signals therefore sufier some hostile channel parameters. The three most important parameters are noise, impedance mismatch, and attenuation which are frequency, time and location variant (7). Subsequently, accurate approximation of the line parameters, the characteristic impedance Z0, and propagation constant ∞, which in turn are used to determine the PLC channel constants, is essential in the channel transfer function calculations. Meticulous measurements are required in the investigation of the channel parameters and consequent modelling of the same. The behaviour of the channel is better understood by varying difierent components, which in the case of PLC, are: the topology; the cable types; the cable length and number of branches; as well as the loads terminating at each end of the network. Once relations of the variations of these are obtained, any given network can then be su-ciently modelled.

Power Line Communications for Low-Voltage Power Grid Tomography

Power line communications (PLC) has attracted considerable attention for supporting smart grid applications. Since it reuses the existing grid infrastructure, it offers cost advantages over alternative communications methods and gives electric utilities control over the communications medium. Furthermore, the through-the-grid property of PLC extends its possible use beyond mere communications. Since the PLC signals are bound to travel through the power grid, they can also be used for inference tasks, such as online diagnostics of power line integrity. In this paper, we consider such an inference application of PLC, enabled by modern signal processing. We assume a power grid at whose edges PLC devices are deployed to form a PLC network for purposes such as advanced meter reading. We are interested in retrieving the physical power-grid topology, i.e., the connections and lengths of power lines reaching to the locations of the PLC devices. To this end, we propose the combination of PLC-based ranging with inference based on end-to-end measurements. In the context of communication networks, the latter is known as tomography and hence, we refer to the developed method as power grid tomography. For the purpose of ranging we formulate a new super-resolution ranging algorithm specifically tailored for signal propagation through power lines. Numerical results for low-voltage distribution grid examples demonstrate the successful reconstruction of the grid topology by the proposed power grid tomography method.

The Design and Realization of Distance Education System Based on the Power Line Carrier

Characterized by extensive coverage, easy connection and huge application potential, power line carrier com- munication has gained increasing attention and become a research hotspot in recent years. This paper started by an intro- duction of the power line carrier communication technology, and then compared it with other networking methods, finally practical power line networking project was proposed. Based on the advantages of power line communication technology, the hardware system was formatted applying four-tier B/S architecture. The computer distance education system was es- tablished using ASP technology in the premise of effective protection of network security. Study shows that the power line communication network is a reliable network education resource, of great significance to promote distance education.

PAPR Reduction in CE-OFDM System for Numerical Transmission via PLC Channel

Power Line Communications have been the subject of an important research work. At the same time, the growing demand for multimedia communications provides a good prospect for PLC as a promising transmission technique for the “last mile” access network. Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally efficient multicarrier modulation technique for high speed data transmission over multipath fading channels. High Peak-to-Average Power Ratio (PAPR) is a major drawback of OFDM. The high PAR of the OFDM signal has to be considered when setting the range of the digital-to-analog converter (DAC) and dimensioning the line-driver. This paper introduced an improved PAPR reduction scheme using constant envelope modulation. Furthermore, by utilizing continuous phase modulation (CPM) in a CE-OFDM system, the PAPR can be effectively reduced to 0 dB. The paper describes a CE-OFDM based modem for Power Line Communications (PLC) over the low voltage distribution network. Relying on a preliminary characterization of a PLC network, a complete description of the modem is given.

지중 저압 전력선의 협대역 전력선통신 채널특성 및 적용성에 대한 연구

본 논문은 국내 지중 저압선에 대한 협대역 PLC 기술의 통신 채널 특성과 이를 기반으로 한 적용성 연구결과에 대해 기술한다. 지중 저압선이 매설된 실제 거주지역에 협대역 PLC 채널 측정을 위한 시스템을 구성하였으며, 이를 통해 채널 응답, 잡음 PSD, 선 임피던스를 포함하는 채널 특성을 측정하였다. 측정된 채널 특성을 분석하여 국내 지중 저압선의 채널 특성이 협대역 PLC 적용에 적합한 특성을 띠며, 250kHz 이후 주파수 대역이 특히 양호한 특성을 나타내는 것을 보였다. 이를 기반으로 IEEE P1901.2 규격을 채택, FCC High 대역을 이용하여 네트워크 테스트를 수행하였으며 이를 통해 국내 지중 저압선에 협대역 PLC 기술의 적용이 가능함을 확인하였다. This paper presents in details channel and noise characteristics over narrow bands below 500kHz based on the field tests over underground low voltage(LV) power lines in residential areas in Korean grid. We show that the channel characteristics of narrowband signals over underground LV power line are decent. We first describe methodology of channel characteristic measurements including channel frequency response, noise, and line impedance, and obtain channel characteristics over the underground LV lines in the residential areas. Also based on the measurement results, we adopt the IEEE P1901.2 standard on the FCC High band, and bring up narrow band power line communication network.

SmartCity Málaga, a real-living lab and its adaptation to electric vehicles in cities

The new energy requirements that will be necessary in the coming years will demand a change in the current paradigm of electricity grids. The need to integrate a higher level of renewable resources to achieve the objectives set by the EU (the famous 20–20–20), flattening the load curve, the imminent arrival of electric vehicles, and the possibility of actively controlling all devices connected to a grid, are some examples of these new challenges. In order to maintain the stability of the distribution network, all medium-voltage lines in the city of Malaga (Spain) have been analyzed and modeled over the past five years, to optimize electric-vehicle charging with the use of available energy during the night valley using pricing signal, control of the electric vehicle charging manager and signals from the Distribution Company, with regard to grid availability (vehicle-charging posts) and available energy. The project has developed new management, control and integration systems for all elements of consumption, production and energy storage over the distribution network. All deployment within the SmartCity Málaga Project of ENDESA includes smartmeters for all customers and new automation and communication systems over the grid connected by a broadband Power Line Communication network.

Topology Estimation for Smart Micro Grids via Powerline Communications

Automated estimation of topology in smart micro grids (SMGs) has been advocated for the optimization of locally generated power. Moreover, when a power line communication (PLC) network is overlaid to the SMG, topology reconstruction is useful also for routing. In this paper, we propose a technique that allows estimating the SMG topology by exploiting PLC signal itself, thus providing an appealing plug-and-play solution for routing optimization. We use measurements of the transmission time taken by the PLC signal to propagate between couples of nodes, and exploit the fact that the communication signal follows the shortest route along the wires to identify the nodes across which it passed. To this end, we cast the topology estimation problem into an hypothesis testing problem, solved by the generalized likelihood ratio test (GLRT). Low complexity solutions based upon a Gaussian approximation of the measurement errors will also be investigated. Performance of the topology estimation technique is assessed on a realistic low voltage outdoor SMG scenario, proving its effectiveness for reliable SMG management.

DESIGNING OF SIMULATION FOR ENGINE ROOM KM. SINABUNG WITH CONTROL MONITORING WEB SERVER BASED BY WIRELESS NETWORK AND POWER LINE COMMUNICATION

Engine room monitoring control system is monitoring and controlling main engine and auxiliary engine from long distance by powerline communication network and wireless network to ease the operator in operating the ship and save operational cost. To prevent error in programming the main engine and auxiliary engine, a simulation using instrument software is needed to know the machine characteristic. After simulation result fulfills the requirement which is approached the value of test record, it can be applied to the real machine. In this study, some steps were done such as: getting know type of main engine and auxiliary engine which performance will be simulated and programmed, getting test record of main engine and auxiliary engine, getting know how the main engine and auxiliary engine work, making simulation of main engine and auxiliary engine work system, doing monitoring control simulation by powerline communication and wireless network, comparing the results between simulation and test record of main engine and auxiliary engine. Engine programming can be set after simulation result meets the requirement. Result of simulation fulfills the requirement, the difference values between machine simulation using software instrument and test record of main engine and auxiliary engine are around 1%-2%. If engine room monitoring control system by wireless and powerline communication is applied in the ship, the ship owner will get advantages because it will prolong ship durability and can monitor operasional of main engine or Auxiliary engine from long distance ; while the operator will be easier in operating the ship. The disadvantage is only the higher cost

Optimal Planning and Routing in Medium Voltage PowerLine Communications Networks

This paper deals with the problem of deploying a PowerLine Communication (PLC) network over a medium voltage (MV) power grid. The PLC network is used to connect the end nodes (ENs) of the MV grid to the service provider by means of PLC network nodes enabled as access points. In particular, a network planning problem is faced wherein we require to define the PLC network topology by deciding which MV network nodes are to be enabled as access points. An optimization problem is then formulated, which minimizes the cost of enabling the access points and maximizes the reliability of PLC network paths in a multi-objective optimization fashion. This work also considers resiliency (i.e., it guarantees the PLC network connectivity even in case of link faults) and capacity constraints (i.e., it checks that there are enough resources to transmit the estimated amount of traffic over the PLC network paths). As a byproduct, the optimization algorithm also returns the optimal routing. Simulations based on realistic MV network topologies validate the proposed approach.

The Establishment of Distance Learning System Based on Power Line Communication Technology

Power Line Communication network has drawn more and more attention and achieved rapid development with its advantages of vast resources and low cost compared with telecommunication network and cable television network. Based on the advantages of Power Line Communication technology, the hardware system was formatted applying four-tier B/S architecture, and the distance learning system based on Power Line Communication technology was established using ASP (Active Server Page) technology. Study shows that the Power Line Communication network is a reliable network learning resources, of great significance to promote distance learning, especially in areas without Internet coverage.

Mitigation of Periodic Impulsive Noise in OFDM-Based Power-Line Communications

This paper presents a novel approach to mitigate the periodic impulsive noise before the synchronization of the orthogonal frequency-division multiplexing (OFDM)-based power-line communications (PLC) system. The proposed algorithm is employed to detect the periodic impulsive noise and then suppresses the periodic impulsive noise with an adaptive infinite impulse response (IIR) notch filter before the synchronization of the system, finally compensating the distortion of received signals brought by the IIR notch filter. Subsequently, the periodic impulsive noise mitigation algorithm is simulated and implemented in the PLC receiver's physical layer. Finally, the proposed algorithm is verified in field-programmable gate array and tested in the indoor PLC network. The simulation and field trial results show that the proposed periodic impulsive noise mitigation technique is simple and effective for the narrowband OFDM-based PLC system, such as the application of automatic meter reading.

Capacity Region of a New Bus Communication Model

In this paper, we study a new bus communication model, where two transmitters wish to send their corresponding private messages and a common message to a destination, while they also wish to send the common message to another receiver connected to the same wire. From an information-theoretical point of view, we first study a general case of this new model (with discrete memoryless channels). The capacity region composed of all achievable (R0,R1,R2) triples is determined for this general model, where R1 and R2 are the transmission rates of the private messages and R0 is the transmission rate of the common message. Then, the result is further explained via the Gaussian example. Finally, we give the capacity region for the new bus communication model with additive Gaussian noises and attenuation factors. This new bus communication model captures various communication scenarios, such as the bus systems in vehicles, and the bus type of communication channel in power line communication (PLC) networks.

Enhanced Operation of Electricity Distribution Grids Through Smart Metering PLC Network Monitoring, Analysis and Grid Conditioning

Low Voltage (LV) electricity distribution grid operations can be improved through a combination of new smart metering systems’ capabilities based on real time Power Line Communications (PLC) and LV grid topology mapping. This paper presents two novel contributions. The first one is a new methodology developed for smart metering PLC network monitoring and analysis. It can be used to obtain relevant information from the grid, thus adding value to existing smart metering deployments and facilitating utility operational activities. A second contribution describes grid conditioning used to obtain LV feeder and phase identification of all connected smart electric meters. Real time availability of such information may help utilities with grid planning, fault location and a more accurate point of supply management.

On rate improvements and power saving with opportunistic relaying in home power line networks

In this article, we investigate the use of half duplex time division relay protocols to possibly provide achievable rate improvements, power saving, and coverage extension in home power line communication (PLC) networks. We consider a network where the communication between the source and the destination nodes follows an opportunistic protocol, namely, the relay is used whenever it allows with respect to the direct transmission: (a) for achievable rate improvements, under a power spectral density (PSD) mask constraint; or (b) for power saving, under a PSD mask and a rate target constraint. Opportunistic decode and forward (ODF), and opportunistic amplify and forward (OAF) are considered. At the physical layer, we assume the use of multi-carrier modulation. Under these assumptions, we find the optimal resource allocation, namely, the optimal power and time slot allocation, between the source and the relay nodes that maximizes the achievable rate, or minimizes the total transmitted power for both ODF and OAF. For the power minimization problem of ODF, we show that the joint problem of power and time slot allocation of DF is very hard to be solved and thus implemented. Therefore, to reduce complexity, we propose a simplified algorithm that considers two convex sub-problems. Through numerical results, we show that its performance is very close to the optimum. Finally, since over in-home PLC networks, the relay can only be placed in accessible points of the network, i.e., in outlets, or in the main panel, or in derivation boxes, for each opportunistic protocol, we also investigate the influence on performances from the relay position. Results are obtained using both measured channel responses and generated ones; thanks to the use of a statistically representative simulator. They show that significant rate improvements and power savings can be obtained as a function of the relay position and network size.

Network Performance of a PLC Protocol for Smart Grid

Implementing smart grid demands a wide area communication network for connecting all the feeder equipments, consumers’ meters and high-consuming appliances, etc, for both utilities’ and consumers’ applications. Using power line itself as a communication medium is an ideal solution for construction of a cost-effective and high speed transmission network. A new flooding-based routing protocol has been developed. The PLC (Power Line Communication) network performances of this protocol are evaluated using theoretical analysis.

FFU Motors Remote Monitoring System Based on Power Line Communication and GPRS

In view of the advantage of low voltage power line carrier technique and general packet radio service(GPRS), a solution of fan filter unit(FFU) motor remote mointoring system based on GPRS and low voltage power line communication is introduced. This system combines a framework of low voltage power line communication and GPRS network with host computer monitoring center, which changes the traditional FFU motor control mode, and realize FFU motor remote real-time on-line automatic monitoring.The system implementation methods were described in detail, and the hardware and sofware design were given.The test and practice showed that the proposed has higher efficient and stronger anti-interference capability, which met the requirements of networkization and intelligentization, and a better way for the FFU motor control. The designed system has good application value.

Design and consideration of integrated PLC and 3G mobile networks as internet of things architecture

Internet of things (IoT) applications are developed and implemented through enlightened communication networks. The phenomena are proving a fact that research in IoT architecture becomes important domain in realising IoT framework. Therefore, in this paper, a new IoT architecture is proposed combining two sophisticated communication networks: power line communication (PLC) and 3G mobile networks. This combination is motivated by scalability advantages of PLC and 3G mobile networks. Further, the 3G-PLC networks testbed is constructed and analysed to show its feasibility in supporting IoT applications.