Power Line Communication Devices Research Articles

Intelligent Sensing Strategy for Grid Anomalies Using Power Line Communication Devices

The difficulty in reusing power line communication equipment for cable aging monitoring is the convergence of aging models and the presence of interference. This study introduces a novel intelligent sensing method that can simultaneously monitor the degree of water tree aging and cable grounding faults in distribution networks. An alternative approach uses backward derivation from channel estimation information from cable-dependent power line carrier devices. Further, it incorporates machine learning to sense dielectric constant anomalies to obtain the real-time status of cable anomalies. The simulation shows that the proposed algorithm can achieve 100% accurate monitoring in the case of pure aging in the grid; it can achieve more than 90% accurate monitoring and predict the aging depth under the coexistence of random load changes and fault disturbances.

Distributed Spectrum Sharing for Enterprise Powerline Communication Networks

As powerline communication (PLC) technology does not require dedicated cabling and network setup, it can be used to easily connect multitude of IoT devices deployed in enterprise environments for sensing and control related applications. IEEE has standardized the PLC protocol in IEEE 1901, also known as HomePlug AV (HPAV) which has been widely adopted in mainstream PLC devices. A key weakness of HPAV protocol is that it does not support spectrum sharing. Currently, each link in an HPAV PLC network operates over the whole available spectrum, and only one link can operate at any time within a single collision domain. In this work, through an extensive measurement study of HPAV PLCs in a real enterprise environment using commodity off-the-shelf (COTS) HPAV PLC devices, we discover that spectrum sharing can significantly benefit enterprise level PLC networks. To this end, we propose a distributed spectrum sharing technique for enterprise HPAV PLC networks, and show that fine-grained distributed spectrum sharing on top of current HPAV MAC protocols can significantly boost the aggregated and per-link throughput, by allowing multiple PLC links to communicate concurrently, while requiring only a few modifications to the existing HPAV devices and protocols.

PLC Systems Under the Presence of a Malicious Wireless Communication Device: Physical Layer Security Analyses

This paper investigates the physical layer security (PLS) of a broadband in-home power line communication (PLC) system when a malicious wireless device tries to eavesdrop private messages exchanged between two PLC devices. Such a security issue arises when electric power circuits, which are used for data communication, are constituted by unshielded power cables. In this regard, the hybrid wiretap channel model for formulating achievable secrecy rate and secrecy outage probability is considered. Additionally, a data set of channel estimates and measured additive noises obtained from a measurement campaign carried out in several in-home facilities is used for providing practical results, which can offer direction for dealing with the security aspects of broadband in-home PLC systems in the physical layer perspective. The attained results show high values of secrecy outage probability for all chosen values of target secrecy rate and total power transmission (practical and theoretical) when the PLC devices are far from each other and the eavesdropper is close to the PLC transmitter (i.e., the distance is shorter than 2 meters). Overall, the numerical results show that the vulnerability of broadband in-home PLC systems, in terms of PLS, is relevant when practical values of total transmission power apply. Therefore, a rethinking of the use of unshielded power cables or new designs of the broadband in-home PLC system deserves special attention for ensuring security at the physical layer.

Emulating the Statistical Properties of Indoor Power Line Colored Background Noise for Development of a Power Line Noise Simulator

This paper deals with the development of a realistic power line channel simulator wherein power line communication devices can be tested before implementation to meet the massive need of data transfer. The statistics of the noise follow the experimentally observed in different sites, namely the time-varying non-white power spectral densities (PSDs) of the background noise and a target non Gaussian amplitude distribution. The procedure based on the inverse cumulative distribution function method of generation of random numbers and iteratively updating a target spectrum necessitates knowledge of a maximum of 17 parameters for successful implementation and has been validated for three sites in the low-frequency ([Formula: see text]500[Formula: see text]kHz) and high-frequency (1–30[Formula: see text]MHz) bands. The average percentage errors in prediction of the mean of the channel capacity (CC) are 12.68% and 10.66% in the two bands, respectively. The minimum correlations of the distribution of BER of OFDM in a channel corrupted by the simulated and observed noises are is 0.883 and 0.801 in the two bands which are high compared to 0.422 and 0.355, respectively, when the requirement of a target amplitude distribution is neglected. With low-frequency noise emulated by a data acquisition card, an average percentage error of 11.82% in the CC and a correlation of 0.867 (against 0.498) in BER are obtained. The noise thus generated can be used as a testbed for system testing, instead of the conventional static models (additive white Gaussian noise or with time-invariant colored PSD), leading to better optimization of the implemented devices.

Statistical Modeling of Brazilian In-Home PLC Channel Features

This paper deals with the statistical modeling of key features of power line communication (PLC) channels that are necessary for designing data communication systems that operate over theses channels. The key features are average channel attenuation, root mean squared delay spread, coherence bandwidth and coherence time. All these features were estimated from in-home PLC channels measured in seven distinct and typical Brazilian residences. Assuming that each feature is a random variable, four criteria (i.e., maximum likelihood estimate and three different information criteria) are used to select the statistical distribution that offers the best fits for each attribute. During this process, the symmetry and asymmetry of the histogram associated with each feature is pointed out. The reported results focus on three frequency bands, namely: from 1.7 MHz up to 30 MHz, from 1.7 MHz up to 50 MHz and from 1.7 MHz up to 100 MHz, which are useful for with Europe, North America and Brazil. The findings report similarities and discrepancies with previous statistical models related to US and Europe and enables one to better design practical PLC devices.

Real-Time Impedance Estimation for Power Line Communication

The real-time broadband properties of impedance in power line communication (PLC) systems are one of the essential characteristics of future smart grids, which would enable the smart online systems to implement fault detection/forecast or the PLC channel health monitoring in the grid. In the current paper, a novel technique was proposed to track impedance only by the channel frequency response (CFR). The CFR can be treated as a known quantity and is normally calculated by the channel estimation algorithms in PLC devices for communication purposes. The relationship between CFR and impedance behavior was first studied in detail, and it was found that the variations in certain key factors, such as the frequency characteristics and the values of peak-valley difference, of the CFR curves could be used to the track real-time impedance. Then, the proposed impedance estimation algorithm harnessed the variational mode decomposition (VMD) as a feature extraction method to obtain useful frequency properties. The machine learning (ML)-based impedance model was also synthesized in the proposed approach. The performance of the proposed impedance tracking method was examined under two different scenarios, and the obtained simulation results demonstrated the efficiencies of the formulated algorithms.

Detection and Location of High Impedance Faults in Multiconductor Overhead Distribution Lines Using Power Line Communication Devices

An effective power system protection scheme has to be able to detect and locate all occurring faults corresponding to low and high impedance values. The latter category poses the greatest challenge for the protection schemes due to the low values of the related fault current. This paper extends previous work by the authors on the subject, aiming to achieve detection and location of high impedance faults (HIFs) in multiconductor overhead distribution networks utilizing power line communication (PLC) devices. Fault detection is proposed to be performed by a PLC device installed at the starting point of the monitored line and by using differences to the values of metrics related to input impedance at frequencies utilized by narrowband systems. Moreover, fault location can be derived by a response to impulse injection procedure utilized by all installed PLC devices along the line. The method is evaluated and validated in various simulation test cases concerning its ability to effectively detect and locate HIFs.

Enhanced Protection Scheme for Smart Grids Using Power Line Communications Techniques—Part II: Location of High Impedance Fault Position

An effective protection scheme against high impedance faults (HIFs) has to efficiently confront the issues of detection and location simultaneously. In Part I of this study the issue of detection is investigated, while in Part II a method that deals with the exact location of HIF position using an installed power line communication (PLC) system is elaborated. This method comprises specific test signal injections into the power grid after a HIF alarm is set. Using impulse responses that are recorded by the PLC devices, the location of the fault may be derived. A flowchart that describes the usage of the complete method for HIF detection and location is presented. The impulse responses that correspond to several fault cases are shown and the methodology that may lead to the fault location is explained. The effect of the fault type and its impedance on the efficacy of the method is highlighted. Finally, the model is applied to a line that is part of the Greek rural distribution system and its validity is tested.