25 th International Conference on Electricity Distribution Madrid, 3-6 June 2019 Paper n° 1911 CIRED 2019 1/5 THE NEED TO REDEFINE EMC STANDARDIZATION: POWER SPECTRAL DENSITY LIMITS OF NON-INTENTIONAL EMISSIONS FOR RELIABLE NB-PLC COMMUNICATIONS Noelia URIBE-PÉREZ Ibon ARECHALDE Alberto SENDIN TECNALIA – Spain TECNALIA – Spain IBERDROLA - Spain noelia.uribe@tecnalia.com ibon.arechalde@tecnalia.com asendin@iberdrola.es Ainara FERNANDEZ Juan Sebastian GOMEZ IBERDROLA – Spain IBERDROLA – Spain afernandezol@iberdrola.es jgua@iberdrola.es ABSTRACT Existing problems from Non-Intentional Emissions (NIE) over NB-PLC devices are well known to the community as well as widely covered in related researches and in reports of technical committees. Currently, the various limits set in different EMC standards for compatibility levels below 150 kHz are neither based on total power injected, nor based in real field measurements, so their validity may be questioned. In this sense, this paper presents a set of tests aiming at addressing both the influence of different emissions over different NB-PLC metering devices and the need to fix limits in the unintentional power injected in NB-PLC bands. The results and conclusions of the study present a valuable input for a fair coexistence between NB-PLC and electrical and electronic devices that can disturb signalling over LV grids below 150 kHz. The paper gives details of the performance evaluation of NB-PLC technologies, relevant for practicable smart meters implementation to improve resistance against NIE. Furthermore, the paper demonstrates that the power density of NIE should be limited in EMC standards to ensure a correct coexistence of NIE sources and NB-PLC technologies. INTRODUCTION The success of NarrowBand Power Line Communications (NB-PLC) for Automated Metering Infrastructure (AMI) is evident from the high number of mature deployments around the world. This poses the question of whether other applications beyond metering could also be considered over PLC [1]. A crucial question in this respect is how to ensure the performance of the communications channel, in which Non-Intentional Emissions (NIE) present throughout Low Voltage (LV) grids represent the main, most adverse influence. Problems caused by interference to PLC devices are well known to the Smart Grid community. This is so to the extent that relevant standardization bodies such as IEC, CENELEC, and ETSI have created specific working groups to address the issue [2]. Back in 2015, CENELEC Subcommittee SC 205A Mains communicating systems published the Third Edition of the Study Report on "Electromagnetic Interference between Electrical Equipment in the Frequency Range from 2 to 150 kHz" [3]. This Report concluded more measurements were needed to better understand the interferences that affect existing PLC technologies in that frequency range. Furthermore, “Investigation Results on Electromagnetic Interference in the Frequency Range below 150 kHz”, was also published by CENELEC SC 205A as a Technical Report in 2017, presented a comprehensive set of additional measurement results on electromagnetic interference [4]. A clear conclusion from the Report was on the need to close the then-existing gap in standardization related to EMC in the frequency range 2 kHz – 150 kHz. In Europe, European Commission included the family of standards EN 50065 [5] as harmonized standards according to the 2014/30/EU EMC Directive [6] to regulate signalling on low-voltage electrical installations in the frequency range 3 kHz to 148,5 kHz. Unfortunately, this regulation that limits the NB-PLC communications is not extended to other products that may inject noise in LV grids below 150 kHz. Two amendments -published in 2017 and 2018- to International Standard IEC 61000-2-2:2002 Electromagnetic compatibility (EMC) - Part 2-2: Environment - Compatibility levels for low-frequency conducted disturbances and signalling in public low- voltage power supply systems tried to represent a first step towards a final solution, by defining compatibility levels below 150 kHz. The compatibility levels are not based in real field measurements but rather in a compromise between theoretical curves, so their validity is to be questioned. Compatibility levels in any case must be converted into generic emission and immunity limits, and then find their way into EMC product standards. The current various limits set in different EMC standards for emissions (and immunity) below 150 kHz can be seen in Figure 1. Moreover, compatibility levels ignore the fact that from a telecommunications perspective, it is the total injected power the magnitude that determines SNR and, as a consequence, performance of telecommunication systems. If the power spectral density, and the total injected power are not limited, SNR and performance