Impact of Channel Disturbances on Current Narrowband Power Line Communications and Lessons to Be Learnt for the Future Technologies

[EN] The electricity network is a complex communication medium with properties that depend on both the topology of the grid and the usage pattern of the connected devices. These devices generate channel disturbances during normal operation, which need to be overcome by power line communications (PLC) transmission technologies for ensuring communication. This paper analyzes the influence of the channel disturbances on the performance of the physical layer of the main narrowband PLC technologies approved by international communication organisms and currently deployed in Europe: PoweRline Intelligent Metering Evolution (PRIME) 1.3.6, PRIME 1.4 and G3-PLC. The methodology of this paper applies a standardized test method, metrics and a set of representative channel disturbances defined by the European Telecommunications Standards Institute (ETSI). Moreover, noise recordings from field measurements in an environment equipped with distributed energy resources (DER) complete the subset of the types of noise used in the study. This paper develops a replicable, fully automated, and cost optimized test scenario, based on an innovative Virtual PLC Laboratory, which provides a replicable and automated test process, where a wide range of channel disturbances can be accurately replicated, and the performance of the PLC technologies can be compared under the same conditions. The results of this paper provide important conclusions to be applied in the development of future PLC technologie

Virtual PLC Lab Enabled Physical Layer Improvement Proposals for PRIME and G3-PLC Standards

Narrowband (NB) powerline communication (PLC) is extensively adopted by utilities for the communication in advanced metering infrastructure (AMI) systems. PLC technology needs to overcome channel disturbances present in certain grid segments. This study analyzes improvement proposals of the physical layer of the main narrowband PLC technologies approved by international communication organizations that are currently deployed in Europe: Powerline Intelligent Metering Evolution (PRIME) 1.3.6, PRIME 1.4, and G3-PLC, in order to improve PLC performance under channel disturbances. This thorough study is based on simulations carried out by an innovative ad hoc Virtual PLC Lab, developed by the authors, applied in replicable, fully-automated, and cost reduced test scenarios. The analysis is performed by applying standardized test methods and metrics, and by evaluating the influence of a set of representative channel disturbances defined by the European Telecommunications Standards Institute (ETSI) and selected noises generated by distributed energy resources (DER) in normal operation. PLC performance improvements in terms of equalizer curve fitting, error correction codes, and noisy subcarrier suppression mechanisms are presented. The performance gain due to each physical improvement proposal is accurately measured and compared under the same conditions in a replicable and automated test environment in order to evaluate the use of the proposals in the evolution of future PLC technologies.This work was financially supported in part by the Basque Government under the grant numbers Elkartek KK-2018/00037 and IT1234-19, and by the Spanish Government under the grant RTI2018-099162-B-I00 (MCIU/AEI/FEDER, UE)

State of the Art and Trends Review of Smart Metering in Electricity Grids

Climate change, awareness of energy efficiency, new trends in electricity markets, the obsolescence of the actual electricity model, and the gradual conversion of consumers to prosumer profiles are the main agents of progressive change in electricity systems towards the Smart Grid paradigm. The introduction of multiple distributed generation and storage resources, with a strong involvement of renewable energies, exposes the necessity of advanced metering or Smart Metering systems, able to manage and control those distributed resources. Due to the heterogeneity of the Smart Metering systems and the specific features of each grid, it is easy to find in the related literature a wide range of solutions with different features. This work describes the key elements in a Smart Metering system and compiles the most employed technologies and standards as well as their main features. Since Smart Metering systems can perform jointly with other activities, these growing initiatives are also addressed. Finally, a revision of the main trends in Smart Metering uses and deployments worldwide is included.his work has been partially supported by the Spanish Ministry of Economy and Competitiveness (project TEC2015-67868-C3-1-R), the University of the Basque Country (UPV/EHU) within the program for the specialization of the postdoctoral researcher staff, and Microgrids with Renewable Distributed Generation (MIGEDIR) (project 713RT0468), funded by the Science and Technology for Development Iberoamerican Program (CYTED)

Field Trials for the Characterization of Non-Intentional Emissions at Low-Voltage Grid in the Frequency Range Assigned to NB-PLC Technologies

The paper describes the results of a measurement campaign to characterize the non-intentional emissions (NIE) that are present in the low voltage section of the electrical grid, within the frequency range assigned to narrowband power line communications (NB-PLC), from 20 kHz to 500 kHz. These NIE may severely degrade the quality of the communications and, in some cases, even isolate the transmission devices. For this reason, the identification and characterization of these perturbations are important aspects for the proper performance of the smart grid services based on PLC. The proper characterization of NIE in this frequency range is a key aspect for the selection of efficient configurations to find the best trade-off between data throughput and robustness, or even for the definition of new improved error detection and correction methods. The huge number of types of NIE, together with the wide variety of grid topologies and loads distribution (density and location of homes and industrial facilities) are great challenges that complicate the thorough characterization of NIE. This work contributes with results from field trials in different scenarios, the identification of different types of NIE and the characterization both in time and frequency domains of all the registered disturbances. This contribution will be helpful for a better knowledge of the electrical grid as a transmission medium for PLC and, therefore, for evaluating the appropriateness of different robustness techniques to be applied in the next generation of smart grid services.This work was funded in part by the Basque Government under the grants IT1234-19 and Elkartek KK-2018/00037 and the Spanish Government under the grant RTI2018-099162-B-I00 (MCIU/AEI/FEDER-UE)

Characterization of the Potential Effects of EMC Filters for Power Converters on Narrowband Power Line Communications

Electromagnetic Compatibility (EMC) filters are one of the main solutions for dealing with the disturbances generated by power inverters. However, they show series/parallel resonances that introduce variations in the impedance seen from the grid. Consequently, in some cases, these filters have low impedances at resonance frequencies, which can affect Narrowband Power Line Communications (NB-PLC) due to notching effects. For that reason, the potential effects of four EMC filters on NB-PLC have been studied. Laboratory trials in a controlled environment have been carried out, in which the attenuation and the Signal-to-Noise Ratio (SNR) thresholds that define the communication’s quality have been studied. The results presented in this paper show that, although the variations of the channel frequency response are not selective enough to degrade the communication thresholds, the attenuation measured when the filter is connected near the receiver might be sufficiently high to be critical for the communications in some situations. Therefore, EMC filters might have a negative impact on NB-PLC that had not been previously considered.This research was funded by the BASQUE GOVERNMENT, grant number IT1234-19 and SPANISH GOVERNMENT, grant number RTI2018-099162-B-I00 (MCIU/AEI/FEDER-UE)

Empirical Analysis of Medium Wave Field Strength Prediction in Urban Environments

[EN] This paper presents results obtained from four extensive field trials of medium wave DRM (Digital Radio Mondiale) which were carried out in Madrid (Spain), Delhi (India) and Mexico D.F. (Mexico) using different transmission frequencies. The objective is to provide medium wave field strength spatial variability values for urban environments using empirical analysis methodology. The influence of the transmission frequency on medium wave propagation in urban environments is included. Both, long and short term components of the signal spatial variability are studied characterizing wide, medium and narrow streets, and the attenuation caused by different urban fast variation occurrences is statistically featured. All the results presented in this paper are essential for future network planning of new emerging digital broadcasting services and have been validated using the Generalized Lee Method

Smart Grid Applications for a Practical Implementation of IP over Narrowband Power Line Communications

Abstract Currently, Advanced Metering Infrastructure (AMI) systems have equipped the low voltage section with a communication system that is being used mainly for metering purposes, but it can be further employed for additional applications related to the Smart Grid (SG) concept. This paper explores the potential applications beyond metering of the available channel in a Power Line Communication-based AMI system. To that end, IP has been implemented over Narrow Band-Power Line Communication (NB-PLC) in a real microgrid, which includes an AMI system. A thorough review of potential applications for the SG that might be implemented for this representative case is included in order to provide a realistic analysis of the potentiality of NB-PLC beyond smart metering. The results demonstrate that existing AMI systems based on NB-PLC have the capacity to implement additional applications such as remote commands or status signals, which entails an added value for deployed AMI systems.This work has been partially funded by the Basque Government (IT.683-13 and ELKARTEK KK-2017/00071

An Empirical Comparative Study of Prediction Methods for Estimating Multipath Due to Signal Scattering from Wind Turbines on Digital TV Services

[EN] Several authors have theoretically studied the effect of wind turbines on the propagation of electromagnetic waves in the UHF band. The International Telecommunication Union also proposes a simplified model to evaluate the impact caused to television reception by a wind turbine in the Recommendation ITU-R BT.805. This paper presents an empirical study of the above mentioned prediction methods for estimating signal scattering from wind turbines in the UHF band, comparing predicted values with empirical data obtained from a DTV measurement campaign carried out in Spain. As signal scattering is independent of the transmission standard or modulation, the results are applicable to any broadcasting and wireless communication signals in the UHF band that may be affected by the multipath interference caused by a wind farm.This work was supported in part by the Basque Government under both the SAIOTEK program and the program for the training of the researcher staff (BFI08.230)

On-field evaluation of the performance of IP-based data transmission over narrowband PLC for smart grid applications

[EN] One of the current efforts for the grid modernization is the deployment of Advanced Metering Infrastructure systems. Regarding AMI technologies, NarrowBand PLC is one of the most spread technologies worldwide. While current AMI deployments based on NB-PLC focus on metering applications, this work addresses the operation of IP over NB-PLC for Smart Grid applications. IP is a well-established standard that might become the key enabler for the interoperability amongst numerous applications for the Smart Grid. In this scenario, on-field measurements become essential to test the coexistence of AMI systems and data transmission beyond metering applications. This paper analyses the configurations and parameters that affect the performance of IP over PRIME such as the number of nodes in the subnetwork, switching levels and transport layer protocols, among others. Results show that the topology of the subnetwork plays a key role for the resulting data rates and provide a meaningful contribution towards the implementation of new applications over NB-PLC based on IP data transmission

Statistical relationship between RMS and QP spectra of voltage measurements in the 9–150 kHz range

The main objective of this work is to obtain an empirical relationship between the root-mean-square and the quasi-peak spectra of voltage recordings in the electrical grid, based on a statistical analysis of a set of on-field measurements for the CISPR Band A (9–150 kHz). The lack of a relationship between the weighting root-mean-square and quasi-peak detectors implies the impossibility of calculating quasi-peak (QP) spectra from root-mean-square (RMS) measurements. It is of great interest that quasi-peak values can be estimated by simple calculations from RMS values, so that comparison to compatibility levels could be applied. This work defines an empirical relationship between the statistical variation of instantaneous RMS values over time, the maximum RMS value of these instantaneous values and the QP output. This relationship is described in the form of a simple equation that can be applied to RMS provided by the RM-A method, specifically developed for the CISPR Band A. A method for the fast assessment of QP values from simple RMS receivers is proposed as a potential application of the numerical RMS-QP relationship. Both the numerical RMS-QP relationship and its application as a simple and fast assessment method are evaluated with disturbances recorded in the low voltage grid.This project (18NRM05) has received funding from the EMPIR program co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation program. This work was funded in part by the Basque Government under the grants IT1436–22 and PRE_2022_2_0074. This work was supported in part through grant PID2021–124706OB-I00 funded by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe