Noise generated by modern lamps and the influence on the smart-grid communication network

Abstract: The metal halide lamp is a high energy electric lamp that produces visible light by an electric arc tube and it is a type of high-intensity discharge (HID) that contains a fused quartz and mixture of gases. These lamps inject noise into the smart-grid power line communications (PLC) network. This can have a strong and negative effect when using the PLC system to control the automatic switching of lamps in public places. In this paper we investigate the effects when the metal halide lamps with electronic or electromagnetic ballasts are seen as noise sources on the smart-grid power line network. It is shown that in the CENELEC band: (3 kHz – 150 kHz) the interference level from metal halide lamps is significantly below the allowed maximum PLC signal levels. In the band 150 kHz – 30 MHz however, PLC signals compete with Electromagnetic Compatibility (EMC) levels. The operational methods of the electronic and electromagnetic ballasts when connected to the metal halide lamps are explained

Power quality and electromagnetic compatibility: special report, session 2

The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems. Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages). The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks: Block 1: Electric and Magnetic Fields, EMC, Earthing systems Block 2: Harmonics Block 3: Voltage Variation Block 4: Power Quality Monitoring Two Round Tables will be organised: - Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13) - Reliability Benchmarking - why we should do it? What should be done in future? (RT 15

Influence of LED tubes on the throughput of an indoor broadband PLC channel

Abstract: This paper shows how Light Emitting Diode (LED) Tubes negatively influence the data rate throughput of an indoor broadband Power Line Communications (PLC) channel. This negative influence on the data rate is due to noise being generated by the lamps. Differential Mode measurements were done with two PLC modems communicating and then introducing LED lamps that add noise to the channel. Drops in data throughput rates were measured and compared to a clean (no noise) channel. A significant decrease (up to 50%) in throughput was observed which can have important implications for applications of PLC in the presence of LED Tubes

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

Machine Learning and Data Mining Applications in Power Systems

This Special Issue was intended as a forum to advance research and apply machine-learning and data-mining methods to facilitate the development of modern electric power systems, grids and devices, and smart grids and protection devices, as well as to develop tools for more accurate and efficient power system analysis. Conventional signal processing is no longer adequate to extract all the relevant information from distorted signals through filtering, estimation, and detection to facilitate decision-making and control actions. Machine learning algorithms, optimization techniques and efficient numerical algorithms, distributed signal processing, machine learning, data-mining statistical signal detection, and estimation may help to solve contemporary challenges in modern power systems. The increased use of digital information and control technology can improve the grid’s reliability, security, and efficiency; the dynamic optimization of grid operations; demand response; the incorporation of demand-side resources and integration of energy-efficient resources; distribution automation; and the integration of smart appliances and consumer devices. Signal processing offers the tools needed to convert measurement data to information, and to transform information into actionable intelligence. This Special Issue includes fifteen articles, authored by international research teams from several countries

Impact of modern lighting technology on the power line communications channel

Abstract: In this study, we look at the impact of modern lighting technology on Power Line Communications (PLC). Power Line Communications has become important due to the Smart Grid and Internet of Things (IoT) development. Modern lighting technology has been developed to make efficient use of electric energy. This technology uses power converters to enable the use of different lighting sources. A byproduct of this conversion process is electronic noise. This noise can interfere with the PLC channel. In this study, different lighting technologies are investigated from a noise standpoint and compared to PLC signal levels. Both narrowband and broadband PLC frequency ranges are investigated. This study shows that the influence of noise on the PLC channel depends predominantly on the conversion topology as well as whether filters have been used. The measurement results show that the influence on data communication system can vary in impact from low to severe. Results were obtained for low energy, high energy, indoor and outdoor lighting sources. A common front end topology encounted is the bridge rectifier and high frequency DC-DC converter combination. These topologies are investigated in details. The study presented here shows that lighting technology (causing interference) needs special consideration when designing PLC systems. Of particular importance is the use of filters which ensure compliance with interference standards and limit the noise effects on the PLC signal.D.Ing. (Electrical and Electronic Engineering Science

Impact of modern electronic equipment on the assessment of network harmonic impedance

Network harmonic impedance forms the link between harmonic currents emitted by individual devices and the harmonic voltage levels in the grid. It is essential for the definition of current emission limits in order to ensure Electromagnetic Compatibility between all equipment connected to the grid. Among all electrical equipment in future smart grid electronic devices, like PV inverters, EV chargers or lamps with electronic ballast, will have a dominating share. This is expected to have a considerable impact on the network harmonic impedance characteristic. The paper discusses the frequency-dependent input impedance of different types of modern electronic equipment and its potential impact on the network harmonic impedance. It is shown that the semiconductor switching results in a variation of the impedance within the fundamental cycle. This is not considered by the presently used assessment methods as they assume only passive network elements. Beside a method to measure these variations, several indices are introduced to quantify the level of its impact. The paper aims to provide some impulses for further discussions, particularly about the definition of network harmonic impedance in presence of electronic devices, the necessity to include these variations in realistic harmonic studies and if this has to be considered in the standardization

Beyond Power over Ethernet : the development of Digital Energy Networks for buildings

Alternating current power distribution using analogue control and safety devices has been the dominant process of power distribution within our buildings since the electricity industry began in the late 19th century. However, with advances in digital technology, the seeds of change have been growing over the last decade. Now, with the simultaneous dramatic fall in power requirements of digital devices and corresponding rise in capability of Power over Ethernet, an entire desktop environment can be powered by a single direct current (dc) Ethernet cable. Going beyond this, it will soon be possible to power entire office buildings using dc networks. This means the logic of “one-size fits all” from the existing ac system is no longer relevant and instead there is an opportunity to redesign the power topology to be appropriate for different applications, devices and end-users throughout the building. This paper proposes a 3-tier classification system for the topology of direct current microgrids in commercial buildings – called a Digital Energy Network or DEN. The first tier is power distribution at a full building level (otherwise known as the microgrid); the second tier is power distribution at a room level (the nanogrid); and the third tier is power distribution at a desktop or appliance level (the picogrid). An important aspect of this classification system is how the design focus changes for each grid. For example; a key driver of the picogrid is the usability of the network – high data rates, and low power requirements; however, in the microgrid, the main driver is high power and efficiency at low cost