Power Line Communication Networks Research Articles

Pervasive Energy Monitoring and Control Through Low-Bandwidth Power Line Communication

The Internet of Things (IoT) is growing rapidly, with increasingly sophisticated networking, sensing, and actuation functions embedded into everyday devices. One important IoT application is managing a building’s energy usage by monitoring and controlling its electrical devices. Many existing IoT-enabled devices operate through low-cost and convenient power line networks, using protocols such as X10 and Insteon for communication. However, as these technologies have traditionally targeted low-bandwidth device control, they are often not readily suited to higher bandwidth uses such as continuous energy monitoring. In this paper, we consider the challenge of leveraging existing low-bandwidth power line communication networks for energy monitoring, and present several techniques that enable reliable and high-resolution monitoring in such networks. As a case study, we consider the popular Insteon protocol and show that intelligent polling and event detection methods can reduce the bandwidth requirements and undetected power events in a real-world Insteon network by 50% or more versus naive methods. Our techniques have been employed in a real IoT-enabled smart home, which has collected much of the data publicly released in the UMass Smart* energy dataset.

Noise Sources, Effects and Countermeasures in Narrowband Power-Line Communications Networks: A Practical Approach

The integration of Distributed Generation, Electric Vehicles, and storage without compromising the quality of the power delivery requires the deployment of a communications overlay that allows monitoring and controlling low voltage networks in almost real time. Power Line Communications are gaining momentum for this purpose since they present a great trade-off between economic and technical features. However, the power lines also represent a harsh communications medium which presents different problems such as noise, which is indeed affected by Distributed Generation, Electric Vehicles, and storage. This paper provides a comprehensive overview of the types of noise that affects Narrowband Power Line Communications, including normative noises, noises coming from common electronic devices measured in actual operational power distribution networks, and noises coming from photovoltaic inverters and electric vehicle charging spots measured in a controlled environment. The paper also reviews several techniques to mitigate the effects of noise, paying special attention to passive filtering, as for being one of the most widely used solution to avoid this kind of problems in the field. In addition, the paper presents a set of tests carried out to evaluate the impact of some representative noises on Narrowband Power Line Communications network performance, as well as the effectiveness of different passive filter configurations to mitigate such an impact. In addition, the considered sources of noise can also bring value to further improve PLC communications in the new scenarios of the Smart Grid as an input to theoretical models or simulations.

Allocation of Medium Access Order Over Power Line Communications (PLC) Supported on Weighted Voting Games

Background/Objectives: In PLC networks, the Home Plug for Audio-Video (HPAV) protocol lacks a mechanism that allows optimizing the order of access of the nodes to the channel. The objective of this paper is to propose the use of Power Indexes as a strategy to solve the problem stated before. Methods/Statistical Analysis: This paper proposes two independent scenarios, formed by communications equipment (nodes) in clearly established traffic and channel conditions. The solution to that problem is obtained by using three methods applying Power indexes: Banzhaf, Shapley- Shubik and Deegan-Packel. A comparison of the obtained result is carried out and a Dunnett's test is applied in order to determine which method has a better performance to solve the problem stated before. Findings: The usage of the Game Theory, specially the Power Indexes, is an innovative strategy for the optimization of the order of access to the PLC channel. It is important to state the relevance that the Game theory has acquired as a tool used to analyze complex optimization situations within the communication networks. Furthermore, it is fair to say that no other similar paper has been found in the diverse bibliographic sources consulted. Based on the results obtained by means of the Dunnet test, it was possible to provide evidence that any of the three methods can be considered as a strategy for establishing the order for the nodes to access the channel. Such order will eventually improve the performance of the PLC network (with a 95% confidence). Nonetheless, the optimization method proposed by Shapley-Shubik can be considered as the best method out of the three because it presents the greatest average, and plus, it is the only method in which the difference Di is greater than 0 (Di ≥ 0). Application/Improvements: It is recommended to investigate on alternative methods to calculate Power Indexes that can offer a reduced computational complexity, in order to facilitate its implementation in low-cost embedded systems.

A cooperative modulation recognition: New paradigm for power line networks in smart grid

Power Line communication (PLC) is an attractive approach to provide information transfer services for future smart grids. However, since various modulations are adopted, it is a great challenge to add new nodes to collect the data from the devices or sensors in in-home PLC networks. In this paper, we propose an approach to automatically access to the PLC network by identifying the modulation of signals. To improve the correct recognition rate on identification of modulations, we propose a multiple input and multiple output (MIMO) based cooperative modulation identification scheme. After receiving the recognition results from accessing nodes, the central server makes the comprehensive and accurate recognition decision on the modulation of the PLC network. Furthermore, the fourth-order cumulants for multiple users are adopted as the feature for this modulation classifier. With the feature, we propose an improved modulation classification algorithm based on the maximum likelihood. Simulations show that a high detection rate and low false positive rate can be achieved as we employ the cooperative modulation identifying scheme and the improved recognition algorithm.

Power line communication transfer function computation in real network configurations for performance analysis applications

Despite power line communication is considered a cost-effective solution to communicate electronic devices across the power system, the performance of this technology is highly affected by physical channel factors such as the presence of noise and signal attenuation. Such phenomena are mainly determined by the characteristics of the electrical infrastructure as well as by the network topology. This study presents an analytical approach to systematically compute the signal attenuation between any pair of nodes in real electric power distribution network topologies based on transmission-line theory and graph theory. The proposed methodology has been applied to obtain the attenuation matrix of two representative networks for low and medium voltage. In addition, the results have been used to analyse the communication performance of these networks, where the low voltage network shows better results due to the reduced number of nodes and network length. The conclusions of this study motivate the application of this methodology to power line communication networks planning.

Sub‐channel assignment and link schedule for In‐Home power line communication network

To offer communication capability in an easy and simple deployment, power line communications (PLCs) have recently attracted interest from the smart grid. The effective sub-channel assignment can increase throughput of In-Home (IH) PLC networks with orthogonal frequency division multiplexing scheme distributed over low-voltage areas. Given a logical topology of an IH PLC network, the authors present a formulation to optimise the sub-channel assignment problem as a linear programming with an objective function of maximising the network throughput. It takes into account constraints of the network topology, interference and traffic fairness. According to the solution of the optimising sub-channel assignment problem, the scheduling algorithm of links to obtain channels is developed for every time slot. Evaluation demonstrates that the proposed approach performs much better in improving overall network throughput and ensuring the traffic fairness of network users than conventional ones.

On the Exploitation of Admittance Measurements for Wired Network Topology Derivation

The knowledge of the topology of a wired network is often of fundamental importance. For instance, in the context of Power Line Communications (PLC) networks it is helpful to implement data routing strategies, while in power distribution networks and Smart Micro Grids (SMG) it is required for grid monitoring and for power flow management. In this paper, we use the transmission line theory to shed new light and to show how the topological properties of a wired network can be found exploiting admittance measurements at the nodes. An analytic proof is reported to show that the derivation of the topology can be done in complex networks under certain assumptions. We also analyze the effect of the network background noise on admittance measurements. In this respect, we propose a topology derivation algorithm that works in the presence of noise. We finally analyze the performance of the algorithm using values that are typical of power line distribution networks.

Relay selection in cooperative power line communication: A multi-armed bandit approach

Power line communication (PLC) exploits the existence of installed infrastructure of power delivery system, in order to trans- mit data over power lines. In PLC networks, different nodes of the network are interconnected via power delivery transmission lines, and the data signal is flowing between them. However, the attenu- ation and the harsh environment of the power line communication channels, makes it difficult to establish a reliable communication between two nodes of the network which are separated by a long distance. Relaying and cooperative communication has been used to overcome this problem. In this paper a two-hop cooperative PLC has been studied, where the data is communicated between a trans- mitter and a receiver node, through a single array node which has to be selected from a set of available arrays. The relay selection problemcan be solved by having channel state information (CSI) at transmitter and selecting the relay which results in the best perfor- mance. However, acquiring the channel state information at trans- mitter increases the complexity of the communication system and introduces undesired overhead to the system. We propose a class of machine learning schemes, namely multi-armed bandit (MAB), to solve the relay selection problem without the knowledge of the channel at the transmitter. Furthermore, we develop a new MAB algorithm which exploits the periodicity of the synchronous impul- sive noise of the PLC channel, in order to improve the relay selec- tion algorithm.

Enhanced Amplify-and-Forward Relaying in Non-Gaussian PLC Networks

Relaying over power line communication (PLC) channels has the potential to improve the reliability and robustness of many PLC-based applications. In particular, this paper proposes to enhance the energy efficiency (EE) of a dual-hop relaying PLC system in the presence of impulsive noise by considering energy-harvesting (EH) at the relaying modem. Amplify-and-forward (AF) relaying and time-switching relaying EH protocols are deployed in this paper. The PLC modems are assumed to have the capability to go on low-power consumption sleep mode when they are neither transmitting nor receiving. The system performance is evaluated in terms of EE and average outage probability for which analytical expressions are derived. Using the derived expressions, several system parameters are investigated, such as the channel gain, which is related to the number of network branches, EH time factor and impulsive noise characteristics. Particularly, the optimization problem of the EH time is addressed thoroughly in order to maximize the achievable gains. Results reveal that the proposed system can offer considerable improvements compared with the conventional AF relaying scheme.

Physical Layer Security Over Correlated Log-Normal Cooperative Power Line Communication Channels

Power line communication (PLC) has enabled many smart grid applications and functionalities over the past few years. Secure communications over such links however remain a crucial aspect for further development. Due to their shared nature, akin to wireless, PLC channels can benefit from many wireless-type security techniques, including physical layer security. To this end, and in contrast to existing studies, which focus on non-cooperative PLC systems, this paper considers the application of physical layer security in cooperative PLC networks in the presence of passive eavesdropping. We analyze the performance of such systems using log-normal correlated channel models considering background and impulsive noise components. Furthermore, the impact of PLC/wireless coding diversity on the system secrecy capacity is evaluated. The results include accurate mathematical expressions for providing an insight into the secrecy capacity and outage probability performance of such systems under various network scenarios.

A Statistical Model of the In-Home MIMO PLC Channel Based on European Field Measurements

The multiple-input multiple-output (MIMO) technique is well known in the field of wireless communications, and has recently been proposed to increase the capacity of in-home power line communication (PLC) networks. MIMO PLC employs the protective earth in addition to the classical line and neutral wires to form a multi-sensor transmission channel. By considering the additional reception of common-mode signals, up to two simultaneous transmit ports and four receive ports can be considered. In order to develop new signal processing strategies optimally exploiting the MIMO propagation characteristics and to evaluate their performance, the accurate modeling of the transmission channel is necessary. This paper presents a comprehensive statistical model of the in-home MIMO PLC channel based on an extensive measurement data base collected in six European countries. The paper first analyzes the main MIMO PLC channel parameters, including path loss parameters and wideband parameters, such as the delay spread, coherence bandwidth, and small-scale statistics. A focus is then made on the MIMO correlation matrix, and its modeling using empirical statistical distributions. A fully parameterized channel model is then developed, with a particular emphasis on both the frequency fading structure of the transfer function and the correlation matrix between sub-channels. As a result, the proposed model generates random MIMO PLC channel realizations, statistically representative of the experimental observations.

A reliable opportunistic routing for smart grid with in-home power line communication networks

The topology of in-home power line communication (PLC) networks varies frequently, which makes traditional routing algorithms failure. To solve this problem, an end-to-end transmission time for remaining path (TTRP) metric-based opportunistic routing (TTRPOR) is proposed. Since a local broadcasting scheme is adopted, the algorithm can find the optimal path for forwarding packets in a dynamic PLC network. The closed-form of the outage probability for a PLC channel is derived to estimate the TTRP. It is proved that the average throughput can achieve maximum as the metric TTRP is utilized to sort candidate forwarding nodes. Numerical results show that the end-to-end throughput of networks with TTRPOR, outperforms that of the network adopting DSR and EXOR, especially for the case of varying-topology in-home PLC networks.

Smart Grid: ICT Control for Distributed Energy Resources

The fact that the electrical grid represents a critical and complex infrastructure has prevented it from experiencing major breakthroughs during decades. Therefore, some problems and inefficiencies have been carried around for a long while, up to the point that traditional electrical grid is far away from being prepared to face incoming challenges, such as properly integrating the foreseen high penetration of Distributed Energy Resources (DER), mainly intermittent and stochastic renewable generation, electric vehicles and energy storage, or proactively controlling the energy demand bymeans of the so-called Demand Response (DR) programs. As a result, the electrical grid is currently undergoing slowly but surely its inexorablemetamorphosis under the new paradigm of the so-called Smart Grid. This metamorphosis basically entails evolving from a highly centralized and static system, where few energy generators supply electricity to a huge number of consumption points without exchanging information in real time, into a highly distributed and dynamic system, with many low capacity, geographically distributed generators, which are able to communicate with the consumption points in order to coordinate and optimize their operation. Ensuring the balance and stability of the electrical grid under this new paradigm requires the deployment of a vast number of sensors and actuators which will generate an unprecedented huge amount of data. Thus, highperformance, reliable, secure, and scalable communications networks and Information Technologies (IT) systems play a central role in the Smart Grid, which is driving the next wave of research and innovation in the Information and Communications Technology (ICT) sector. The aim of this special issue was to gather high-quality cutting-edge research papers addressing the use of distributed sensor and actuator networks in SmartGrids, including topics such as novel ICT architectures, wireless and wired communications technologies, interoperability and conformance testing, big data and analytics, and cloud computing, and applications such as Advanced Metering Infrastructures (AMIS), Demand Response (DR), Wide Area Monitoring Systems (WAMS), or transportation electrification. The special issue has attracted the submission of 17 papers. After a thorough peer-review process, seven papers have been accepted for publication. The topics covered in these papers range from Advanced Metering Infrastructures and Demand Response to substation automation and smart lighting, including wireless and powerline communications networks and cybersecurity.

Time synchronization over heterogeneous network for smart grid application: Design and characterization of a real case

Distributed monitoring and control systems are mandatory for the efficient management of the distribution grid, due to the growing presence of renewable energy sources. Time synchronization among devices deployed in distribution grid plays a key role, since a common time reference is essential to correlate power quality and high sampling frequency measure, and generally coordinate any distributed actions. The design and the deployment of a time synchronization system over an existing heterogeneous network is investigated in the paper. The Network Time Protocol (NTP) has been chosen due to its backward compatibility, the good security level, and the intrinsically robust hierarchy. Several NTP synchronization architectures have been proposed and then applied to a real (operating) distribution grid, both at Medium Voltage (MV) and Low Voltage (LV). The experimental validation was carried out during several weeks on the live system. The results in the MV grid highlight the trade-off existing between synchronization accuracy and availability: the synchronization accuracy over MV Broadband Power Line (BPL) links decreases from 20 ms to 50 ms when a more reliable architecture, from the point of view of time synchronization, is used. On the other hand, experimental results show as end-nodes connected on LV grid by means of BPL have a mean offset typically below 50 ms, and a synchronization accuracy on the order of 150 ms. These results are due to the limitation of the synchronization protocol deployed in the LV end-nodes and to scalability issues of power line communication networks when the number of nodes increases.

Advanced metering infrastructure design and test bed experiment using intelligent agents: focusing on the PLC network base technology for Smart Grid system

Today, the power line communication (PLC) is being used for the configuration of Home-Network or factory automation. Due to the improvements in both the stability and the transmission speed resulting from recent digital PLC method, its field of applications is getting broader. Meanwhile, the PLC has been studied widely for it is considered to be the low-cost communication solution that utilizes power distribution network and suitable for the Smart Metering systems. However, involved costs and limited geographical application must be solved to commercialize this technology. On the other hand, the positive economic aspects and potentials in future applications should be recognized. External control of household appliances and automated monitoring and power management can be achieved with the technology. Once such system is implemented and utilized, it will not only contribute to energy conservation but also be able to cope with the power system abnormalities remotely. Despite of these advantages, the PLC technology still reveals its vulnerability in achieving stable communications. Its low-reliability problem caused by the signal interference and attenuation are being discussed and the solution has been described in this study with the results obtained from the test bed experiments.We expect that our system proposed in this paper will become a foundation technology for the Smart Grid.

Interferer Aware Multiple Access Protocol for Power-Line Communication Networks

Hidden station problem can occur in power-line communication (PLC) networks. A simple solution to the problem has been proposed to use request-to-send (RTS)/clear-to-send (CTS) exchange, but this approach cannot solve the hidden station problem perfectly. This paper revisits the problem for PLC networks and designs a protocol to solve it. We first analyze the throughput performance degradation when the hidden station problem occurs in PLC networks. Then, we propose an interferer aware multiple access (IAMA) protocol to enhance throughput and fairness performances, which uses unique characteristics of PLC networks. Using the RTS/CTS exchange adaptively, the IAMA protocol protects receiving stations from being interfered with neighboring networks. Through extensive simulations, we show that our proposed protocol outperforms conventional random access protocols in terms of throughput and fairness.

High‐resolution and low‐complexity dynamic topology estimation for PLC networks assisted by impulsive noise source detection

Power line communication (PLC) network is a promising solution for smart grid and home broadband applications. However, its topology is not always available and is time-varying due to frequent load changes. The existing topology estimation approaches require installation of a large number of PLC modems or suffer limited resolution. Moreover, they are designed for static PLC networks and need to be repeated at a regular basis to combat topology changes. The authors propose a high-resolution and low-complexity dynamic topology estimation scheme for time-varying indoor PLC networks, which consists of three parts: (i) a time-frequency domain reflectometry based path length estimation method, which requires measurement at a single PLC modem and achieves a much higher resolution than the frequency domain reflectometry based method; (ii) a node-by-node greedy algorithm for topology reconstruction, which is much more computationally efficient than the existing peak-by-peak searching algorithm; (iii) an impulsive noise assisted dynamic topology re-estimation method, which results in a significant complexity reduction over fixed-frequency re-estimation.

Planning and Performance Challenges in Power Line Communications Networks for Smart Grids

The Smart Grid represents a revolution especially at distribution and customer levels, bringing monitoring and control capabilities, traditionally available up to the primary substations, down to the secondary substations, and beyond. Machine-to-Machine (M2M) communications networks are key to enable managing the huge number of sensors and actuators distributed all over the low voltage and medium voltage networks. Such M2M communications networks must meet demanding requirements from the technical perspective (e.g., low latency, high availability), since eventually the stability of the grid may rely on them, and from the economic perspective (e.g., low deployment and operational costs), due to the huge volume of devices to be monitored and controlled. Thus, Power Line Communications (PLC) technologies are winning momentum in these scenarios because they represent a great trade-off between both perspectives. However, electrical networks also represent a harsh communications medium, mainly because they are not designed for data communications, but for power transmission. Consequently, although much research has been carried out on this topic recently, PLC networks still present technological problems and challenges. This paper highlights some of the most relevant challenges in this area and presents a set of cutting-edge software tools which are being developed to overcome them, facilitating the planning, deployment, and operation of this kind of networks.

Upper and lower bounds for deterministic broadcast in powerline communication networks

Powerline communication networks assume an interesting position in the communication network space: similarly to wireless networks, powerline networks are based on a shared broadcast medium; unlike wireless networks, however, the signal propagation is constrained to the power lines of the electrical infrastructure, which is essentially a graph. This article presents an algorithmic model to study the design of communication services over powerline communication networks. As a case study, we focus on the fundamental broadcast problem, and present and analyze a distributed algorithm $$\textsc {Color}\textsc {Cast}$$COLORCAST which terminates in at most n communication rounds, where n denotes the network size, even in a model where link qualities are unpredictable and time-varying. For comparison, the achieved broadcast time is lower than what can be achieved by any unknown-topology algorithm (lower bounds $$\varOmega (n\log n / \log (n/D))$$Ω(nlogn/log(n/D)) and $$\varOmega (n \log D)$$Ω(nlogD) are proved in Kowalski and Pelc (Distrib Comput 18(1):43---57, 2005) resp. Clementi et al. (2001) where D is the network diameter). Moreover, existing known-topology broadcast algorithms often fail to deliver the broadcast message entirely in this model. This article also presents a general broadcast lower bound for the powerline model.

전력설비 관리를 위한 무선 및 유선 통신 방법에 관한 고찰

Power plants maintenance data is to be sent to management server system via a communication network. In this case, reliable communication network is required. Transmission of the power plants maintenance data is used in the wired communication network or wireless communication network. PLC communication network is a kind of wired communication network. However PLC communication network is easily affected by noise. On the vulnerable areas in power line system, such as a mountain or rural areas, it is difficult to form a power line communication network. For a wireless communication, environment are also influenced factors in wireless communication. Harsh environmental factors are bring the communication characteristic degradation. In such areas it can be used a combination of two networks and in this way the complementary function can be achieved. Power plants are distributed in various regions across the country. The appropriate communication network is needed to maintain the power plant.This study investigated the effect of environment on the wired communication and wireless communication. It would examine a variable factor which is affect to the communication characteristic. We used PLC communication for wired communication network and ZigBee communication for wireless communication network. We investigated the characteristics of a single communication network and it raised the need for a complex communication technology to complement a single communication network.