Field Trials for the Empirical Characterization of the Low Voltage Grid Access Impedance From 35 kHz to 500 kHz

The access impedance of low-voltage (LV) power networks is a major factor related to the performance of the narrow-band power line communications (NB-PLCs) and, in a wider sense, to electromagnetic compatibility (EMC) performance. Up to date, there is still a lack of knowledge about the frequency-dependent access impedance for frequencies above 9 kHz and up to 500 kHz, which is the band where the NB-PLC operates. The access impedance affects the transmission of the NB-PLC signal, and it determines the propagation of the non-intentional emissions that may disturb other electrical devices, including malfunctioning or reduced lifetime of equipment. This paper presents the results of field measurements of the LV access impedance up to 500 kHz in different scenarios, with measurement locations close to end users and near transformers. The results provide useful information to analyze the characteristics of the LV access impedance, including variation with frequency, ranges of values for different frequency bands, and analysis of specific phenomena. Moreover, the results reveal a diverse frequency-dependent behavior of the access impedance in different scenarios, depending on the grid topology, the number of end users (that is, number and type of connected loads), and the type of transformation center. Overall, the results of this paper offer a better understanding of the transmission of NB-PLC signals and EMC-related phenomena.The authors would like to thank Iberdrola for the availability and the collaboration of authorized staff for carrying out the field trials

A Line Impedance Calculator Based on a G3 PLC Modem Platform

Power line communication (PLC) is one of the most today used technologies for both automatic meter reading and many other smart grid applications. In this framework, a characterization of the electrical network in the PLC frequency range is needed in terms of impedance measurement and received signal level. This can allow choosing the most suitable and less noisy frequency ranges for PLC transmission. Usually, these characterization measurements are performed with dedicated instrumentation and in the absence of mains voltage. This article wants to propose an alternative solution, which allows these kinds of measurements to be performed using electronic boards currently used as on-field applications, such as smart meters. To this aim, an innovative measurement tool is proposed, which does not need a specific characterization signal to be injected because it uses the preamble of a generic PLC transmission. Moreover, the impedance calculation is performed using an FFT analysis, which does not require high computational capabilities. These features allowed the proposed tool to be implemented using a G3-PLC transceiver, embedded in many commercial smart meters, and low-cost additional hardware. This article shows how the proposed system correctly measures the PLC impedance on CENELEC A, B, and FCC frequency ranges

Analysis of power line communications for last-hop backhaul in small cells deployment

Publicado en: :(2019-04-05),(José A. Cortes, Francisco J. Cañete, Matías Toril, Luis Díez, Alicia García-Mozos, "Analysis of power line communications for last-hop backhaul in small cells deployment", in Proceedings of the IEEE International Symposium on Power Line Communications and its Applications, 2019.),yEditor(IEEE)The purpose of this work is to study the feasibility of using power line communications (PLC) over outdoor public lighting networks (OPLN) for last-hop backhaul in small cell deployment. The analysis is based on actual noise measurements performed in two OPLN in the city of Málaga (Spain) and on a bottom-up channel simulator, which has been designed according to the physical characteristics and the common practices in such kind of networks. Estimations of the bit-rate achieved by PLC systems following the ITU-T Rec. G.9960 (G.hn) standard, are performed and discussed. Results indicate that PLC is a promising solution for this application.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Power line communications systems

The purpose of this project is to determine the performance of a Power line communication connection by measuring its propagation characteristics. For power line communication to become efficient, a model of their behaviour at frequencies from 0 to 30 MHz is required. The attenuation and phase response are of particular interest. In this project, indoor cables within a building were utilized. A three core indoor cable is modeled as a two wire lumped-element model with distributed parameters. These parameters are capacitance, inductance, conductance and resistance.The predicted results, generated by MATLAB software closely matched those obtained by the measurements carried out on the 10m flat cable. The model and its results will allow communication designers to determine the optimal communication scheme for this power line channel.However, more investigation is required to determine noise characteristics and impedance mismatch in the power line network before it can be completely modeled

Statistical Characterization of Indian Residential Networks for Powerline Communication

Despite different powerline channel modeling techniques, developed so far, there are still specific dynamic, varying parameters (viz. the random load variation and inconsistent electrical wiring) to be studied for a valid and reliable power line communication (PLC) model. Statistical characterization of PLC channel may provide the required background for refinement of these existent models. In this paper, the Indian residential networks are statistically analyzed in the frequency range of 1-100 MHz. This also includes the comprehensive analysis of line impedance, stationary noise, channel capacity and average channel gain. From the measurements, the noise spectrum density is found to be less than -90 dBm at a frequency less than 1 MHz and is almost constant after 70 MHz. The minimum and maximum channel capacity of the network is 71.5 Mbps and 97.7 Mbps respectively. The Average channel gain is estimated at -30 dB. The paper also reviews the channel transfer function developed by top-down and bottom-top approaches.  Finally, some additional factors influencing the PLC channel are also discussed

Modeling Airfield Ground Lighting Systems for Narrowband Power-Line Communications

Airfield ground lighting (AGL) systems are responsible for providing visual reference to aircrafts in the airport neighborhood. In an AGL system, a large number of lamps are organized in serial circuits and connected to current regulators that supply energy to the lamps. Controlling and monitoring lamps (including detection and location of burnt-out lamps) are critical for cost-saving maintenance and operation of AGL systems. Power-line Communications (PLC) is an attractive technology to connect elements of the AGL, reusing the power distribution cable as a transmission medium. PLC technologies avoid the installation of new wires throughout the airport infrastructure. This paper proposes a new model for power-line communication links in AGL systems. Every element (isolation transformer, primary circuit cable, and lamps) has been analyzed in laboratory and modeled using SPICE. The resulting models have been integrated to build a complete power-line link model. Simulation results are compared to experimental results obtained in real conditions in the Airport of Seville (Spain)

Techniques and Challenges in Conducted EMI Analysis of Renewable Energy Systems

Renewable energy sources have been widely integrated into modern power systems, leading to the massive use of power converters, which represent the main sources of conducted electromagnetic (EM) noise. Furthermore, power grids employ interactive devices including smart meters that resort to powerline communication (PLC) technology and are usually more susceptible to EM noise than traditional electrical machinery. This paper provides a state-of-the-art overview of conducted EM interference (EMI) analysis in power systems, focusing on EMI prediction models, PLC coexistence issues, and measurement challenges. Insights into the use of various methods in different application scenarios are provided, and relevant future studies are foreseen

DC Power Line Communication (PLC) on 868 MHz and 2.4 GHz Wired RF Transceivers

Efficient management through monitoring of Li-ion batteries is critical to the progress of electro-mobility and energy storage globally, since the technology can be hazardous if pushed beyond its safety boundaries. Battery management systems (BMSs) are being actively improved to reduce size, weight, and cost while increasing their capabilities. Using power line communication, wireless monitoring, or hybrid data links are one of the most advanced research directions today. In this work, we propose the use of radio frequency (RF) transceivers as a communication unit that can deliver both wired and wireless services, through their superior analog and digital signal processing capability compared to PLC technology. To validate our approach computational simulation and empirical evaluation was conducted to examine the possibility of using RF transceivers on a direct current (DC) bus for wired BMS. A key advantage of this study is that it proposes a flexible and tested system for communication across a variety of network scenarios, where wireless data links over disrupted connections may be enabled by using this technology in short-range wired modes. This investigation demonstrates that the IEEE 802.15.4-compliant transceivers with operating frequencies of 868 MHz and 2.4 GHz can establish stable data links on a DC bus via capacitive coupling at high data rates