An overview of colour LED & CFL lighting interference on the low voltage PLC network

Abstract: Light sources are being competitive in the current market. Several types of these products have been widely used in the last two decades. They play a major role on the low voltage network as they produce and inject undesired noise onto the transmission lines of the PLC channel. This noise can be of a serious and negative effect when using the power line communications system to control the automatic switching of lamps in residential areas and public places. The main colour low-energy indoor light sources that exist in the market, such as, LEDs and CFLs have been tested for the noise generation on the PLC channel and the results are analyzed and shown in this study. A mathematical analysis of LED bridge rectifier is introduced in this study

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

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

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

Using an LED as a sensor and visible light communication device in a smart illumination system

The need for more efficient illumination systems has led to the proliferation of Solid-State Lighting (SSL) systems, which offer optimized power consumption. SSL systems are comprised of LED devices which are intrinsically fast devices and permit very fast light modulation. This, along with the congestion of the radio frequency spectrum has paved the path for the emergence of Visible Light Communication (VLC) systems. VLC uses free space to convey information by using light modulation. Notwithstanding, as VLC systems proliferate and cost competitiveness ensues, there are two important aspects to be considered. State-of-the-art VLC implementations use power demanding PAs, and thus it is important to investigate if regular, existent Switched-Mode Power Supply (SMPS) circuits can be adapted for VLC use. A 28 W buck regulator was implemented using a off-the-shelf LED Driver integrated circuit, using both series and parallel dimming techniques. Results show that optical clock frequencies up to 500 kHz are achievable without any major modification besides adequate component sizing. The use of an LED as a sensor was investigated, in a short-range, low-data-rate perspective. Results show successful communication in an LED-to-LED configuration, with enhanced range when using LED strings as sensors. Besides, LEDs present spectral selective sensitivity, which makes them good contenders for a multi-colour LED-to-LED system, such as in the use of RGB displays and lamps. Ultimately, the present work shows evidence that LEDs can be used as a dual-purpose device, enabling not only illumination, but also bi-directional data communication

Heating Effects Through Harmonic Distortion on Electric Cables in the Built Environment

Under ideal circumstances, electric power supply voltage and current waveforms should be sinusoidal. However, this is very seldom the case in the built environment, due to the proliferation of non-linear loads. Examples of non-linear loads are those containing switched mode power supplies, reactors and electronic rectifiers/inverters. Common devices such as personal computers, fluorescent lighting, electric motors, variable speed drives, transformers and reactors and virtually all other electronic equipment are examples of non-linear loads. Non-linear loads are the norm in the built environment rather than the exception. Such loads produce complex current and voltage waves and simple spectral analysis of these complex waves shows that they can be represented by a wave at the fundamental power frequency plus other wave forms at integer and non-integer multiples of this frequency. These harmonics produce an overall effect called \u27Harmonic Distortion\u27 which can give rise to overheating in plant, equipment and the power cables supplying them, leading to reduced efficiency, operational life and sometimes failure. Over the last few decades, harmonic distortion in power supplies has increased significantly due to the increasing use of electronic components in industry and elsewhere. Buildings such as modern office blocks, commercial premises, factories, hospitals, etc.,contain equipment that generates harmonic loads as described above. Each item of equipment produces a unique harmonic signature and therefore a harmonic distortion which can be predicted if the equipment in use can be determined in advance. This thesis seeks to identify the harmonic signatures of different types of equipment commonly used and to predict the thermal loading effects on distribution cables caused by the skin and proximity effects of harmonic currents

The impact of energy efficient lighting on power networks.

M.Sc.Eng. University of KwaZulu-Natal, Durban 2013.The power utilities in many countries have come under stress as a result of generation capacity deficits, looming fuel costs and in many developing countries the electricity demand is very quickly outstripping the available electricity supply [1]. Since 2006, Eskom has been utilizing large scale residential efficient lighting roll out programmes as a cost effective short to medium term supply security solution while the longer term capital intensive supply side, “Build Programme” was underway [2]. This mostly involved the use of non-linear compact fluorescent lamps (CFLs) to replace linear incandescent lights (ILs) with very little involvement and influence by the utility QOS (quality of supply) engineers that are responsible for ensuring supply quality on the specifically targeted Distribution networks. This dissertation highlights that while CFLs can provide the desired energy or peak power reduction required, they can also have an impact on QOS within specific sensitive networks if the appropriate CFL standards (i.e. IEC 61000-3-2) minimum requirements are not adhered for both power factor and harmonics. These large scale CFL implementations have cost implications and hence metering and verification methods and models have been developed to simulate and quantify the returns from investing in energy efficient lighting initiatives. CFL manufacturers differ on ballast designs which have a direct impact on lamp efficacy, harmonic distortion and power factor which contribute to network quality of supply. It is for this reason that this dissertation raises an awareness of the importance of appropriate CFL standards i.t.o. the impact on quality of supply from a harmonics and power factor perspective. Due to the lack of more recent available or reliable sources of CFL test data, laboratory investigations were used to confirm the harmonics and PF characteristics of a variety of commercially available CFLs in addition to those utilised in previous large scale rollout programmes. The harmonics and power factor performance measured were compared for compliance against the international limits as prescribed in IEC 61000-3-2. Further investigations on international lighting industry standards for CFL’s has revealed gaps pertaining to harmonics and PF limits. This study is concluded by highlighting the impact of CFLs on power networks. It also provides a brief guide for utility power quality engineers by imparting an understanding of their role for the large scale efficient lighting programmes in order to pro-actively contain any possible impact on quality of supply within the regulatory limits as prescribed in the QOS standards

A review of gallium nitride LEDs for multi-gigabit-per-second visible light data communications

The field of visible light communications (VLC) has gained significant interest over the last decade, in both fibre and free-space embodiments. In fibre systems, the availability of low cost plastic optical fibre (POF) that is compatible with visible data communications has been a key enabler. In free-space applications, the availability of hundreds of THz of the unregulated spectrum makes VLC attractive for wireless communications. This paper provides an overview of the recent developments in VLC systems based on gallium nitride (GaN) light-emitting diodes (LEDs), covering aspects from sources to systems. The state-of-the-art technology enabling bandwidth of GaN LEDs in the range of >400 MHz is explored. Furthermore, advances in key technologies, including advanced modulation, equalisation, and multiplexing that have enabled free-space VLC data rates beyond 10 Gb/s are also outlined

Proceedings of the 8th International Conference on Energy Efficiency in Domestic Appliances and Lighting

At the EEDAL'15 conference 128 papers dealing with energy consumption and energy efficiency improvements for the residential sector have been presented. Papers focused policies and programmes, technologies and consumer behaviour. Special focus was on standards and labels, demand response and smart meters. All the paper s have been peer reviewed by experts in the sector.JRC.F.7-Renewables and Energy Efficienc

Proceedings of the 7th International Conference EEDAL 2013 Energy Efficiency in Domestic Appliances and Lighting

This book contains the papers presented at the seventh international conference on Energy Efficiency in Domestic Appliances and Lighting. EEDAL'2013 was organised in Coimbra, Portugal in September 2013. This major international conference, which was previously been staged in Florence 1997, Naples 2000, Turin 2003, London 2006, B2e0r0l9in, Copenhagen 2011 has been very successful in attracting an international community of stakeholders dealing with residential appliances, equipment, metering liagnhdti ng (including manufacturers, retailers, consumers, governments, international organisations aangde ncies, academia and experts) to discuss the progress achieved in technologies, behavioural aspects and poliacineds , the strategies that need to be implemented to further progress this important work. Potential readers who may benefit from this book include researchers, engineers, policymakers, and all those who can influence the design, selection, application, and operation of electrical appliances and lighting.JRC.F.7-Renewables and Energy Efficienc