End-user Equipment Research Articles

Load-Dependent Power-Efficient Passive Optical Network Architectures

Passive optical networks consume nearly 70% of peak power even when the network load is almost zero (i.e., off-peak). To reduce power consumption under low-load conditions, we propose the concept of a flexible network architecture. Each architecture is a unique combination of central office, subscriber, and end-user equipment variants. Three such architectures are proposed. The architecture that minimizes the overall power consumption of the network can be chosen provided its network performance is within an acceptable range. Using numerical evaluation, we observe that three of these architectures perform better than the others. We describe the network operation for these architectures and then evaluate their network performance using simulations. For two of the studied scenarios, it is shown that at least 35% power savings can be achieved by adopting a proposed architecture during off-peak network loads, without significant performance impact in terms of throughput and packet delay.

Carbon footprint of movie distribution via the internet: a Swedish case study

Abstract Peer-to-peer (P2P) has been suggested as an energy-efficient means of movie distribution, indicating potential environmental benefits. An alternative option for the user would be to stream the movie from an internet protocol television (IPTV) solution. This paper presents an assessment of the carbon footprint of these two alternatives. When studying the environmental impacts of a product (goods or services), it is important to adopt a life cycle perspective in order to avoid moving the potential impacts from one part of the life cycle to another. Therefore the carbon footprint was assessed with a screening life cycle assessment (LCA). The results show that end-use equipment and distribution (in both P2P and IPTV systems) are clearly key aspects. Both manufacturing and use are important. In the use phase, the electricity for using the end-use devices and for distribution is the main contributor to the carbon footprint. For the distribution, another major contributor to the carbon footprint is the construction work involved in installing cables. Downlink/uplink bandwidth and movie size have a major influence on the environmental impact related to watching a movie by P2P, as the total time for which end-use devices need to be used is critical. Movie size determines the impact related to the distribution. In terms of the carbon footprint from the two systems, the P2P system has a higher impact, mainly caused by the end-use devices. Downlink–uplink bandwidth and movie size determine the overall impact of the P2P system. The carbon footprint from P2P systems could be lowered either through higher uplink bandwidth or through decreased movie size.

LVDC 배전계통의 접지방식에 따른 인체안전 및 계통영향 분석

Recent developments and trends in the electric power consumption clearly indicate an increasing use of DC in end-user equipment. According to the trends, new DC power distribution systems have been researched and developed although we presently enjoy a predominantly AC power distribution system. We can use various grounding schemes in DC distribution system as well as in AC distribution system to protect human body and equipments. However, we need to evaluate carefully which grounding scheme is appropriate for a specific system before applying those schemes. In this paper, we analyze the human safety and system effect according to various grounding schemes in Low Voltage DC (LVDC) distribution system. Some components in LVDC distribution system are modeled and computer simulations are conducted by using ElectroMagnetic Transient Program (EMTP).

Ammonia and gasoline composite liquid fuel blends emulsified with ethanol and methanol for direct displacement in internal combustion engines

Ammonia, when blended with hydro carbon fuels, can be used as a composite fuel to power existing IC engines using the hydrogen energy contains in the chemical. Such blends, similar to ethanol and gasoline fuel blends can be used to commercialize ammonia as an alternative fuel. Feasibility of developing ammonia gasoline liquid fuel blends and the use of ethanol and methanol as emulsifiers to enhance the solubility of ammonia in gasoline were studied using thermostated vapor liquid equilibrium (VLE) high pressure cells, in this research. A small VLE cell was used to quantify the solubility of ammonia in gasoline more accurately and a larger VLE cell was used to develop identified fuel blends in sufficient quantities for engine dynamometer tests. A SuperFlow model 902 engine dynamometer with a GM family II Ecotec LE5 2.4L gasoline engine was used to benchmark performance of ammonia fuel blends against standard fuels. Solubility test results prove that emulsifier free pure gasoline is capable of dissolving 23 g/l of ammonia on mass basis (4.5% of ammonia on volume basis) at 50 Psi pressure and 286.65 K temperature in liquid phase. Solubility level is increased with the use of ethanol and methanol. Gasoline with 10% ethanol can retain 51.4 g/l (11.0% on volume basis) of ammonia in the liquid phase at the same pressure and temperature. Methanol has better emulsifying capabilities. Solubility level of gasoline with 10% methanol is 61.8 g/l (11.0% on volume basis). Dynamometer results show the ability of new composite fuel blends to produce the same amount of torque and power in the lower rpm limits. At higher rpm levels ammonia rich fuels result in an increased torque and power. Thus it can be concluded that hydrogen energy can be stored as ammonia-gasoline fuel blends and recovered back successfully without any strenuous modification to the existing infrastructure and end user equipment or behavior.

A method for forensic artefact collection, analysis and incident response in environments running session initiation protocol and session description protocol

In this paper, we perform an analysis of SIP, a popular voice over IP (VoIP) protocol and propose a framework for capturing and analysing volatile VoIP data in order to determine forensic readiness requirements for effectively identifying an attacker. The analysis was performed on real attack data and the findings were encouraging. It seems that if appropriate forensic readiness processes and controls are in place, a wealth of evidence can be obtained. The type of the end user equipment of the internal users, the private IP, the software that is used can help build a reliable baseline information database. On the other hand the private IP addresses of the potential attacker even during the presence of NAT services, as well as and the attack tools employed by the malicious parties are logged for further analysis.

Mitigation of Voltage sag and Harmonics in Grid connected Wind Energy System using STATCOM

Power quality gains its importance with the introduction of sophisticated electrical gadgets. The performances of these devices are sensitive to the quality of input power supply. Various power quality problems results in failure or mal-operation of end user equipment. Some of the major power quality issues are voltage sag, voltage swell and harmonics. To solve these problems, capacitors, voltage regulators and filters, are conventionally used. These techniques involve inherent drawbacks. So it is proposed to use Flexible AC Transmission System (FACTS) devices for the mitigation of power quality problems. With the usage of these devices, drawbacks associated with conventional methods can be overcome easily. The application of FACTS devices provides faster control and enhances the way of using the transmission system at their rated thermal capability. In this work, it is proposed to use Static Var Compensator (STATCOM) for mitigating voltage sag and harmonics by providing proper reactive power support. The device is modelled and simulated using MATLAB-SIMULINK. In order to validate the proposed approach, it is tested with three phase fault simulated in the designed model. The graphical, numerical results with and without STATCOM are compared to measure the effectiveness of control.

Research on TCSC and Active Power Filter Apply to Improve Power Grid Based on Matlab Analysis

Industrial and agricultural production as well as the general public because the demand for is much larger, the electricity grids integrated-transportation network multiple transformer output to the end-use equipment bring great difficulties and many other different failures, resulting in a lot of energy wasted . This article is mainly to use the thyristor controllable series compensated (short for TCSC) for power during transmission of some compensation to make the system voltage stabilized and improved, combining with active power filter (short for APF) will suppress and filter out a series of primary and secondary synchronization harmonic interference etc. not only improve the effectiveness and utilization of electrical energy, but also purify the electricity grid environment. By the simulation results show that the power to improve the stability and quality are very good results.

The savings of energy saving: interactions between energy supply and demand-side options—quantification for Portugal

Reducing demand by increasing end-use energy efficiency on the demand side of energy systems may also have advantages in reducing fossil dependency and greenhouse gas (GHG) emissions on the supply side. This paper addresses interactions between energy supply- and demand-side policies, by estimating the impact of measures addressing end-use energy efficiency and small-scale renewables uses in terms of (1) avoided large-scale electricity generation capacity, (2) final energy consumption, (3) share of renewables in final energy and (4) reduction of GHG emissions. The Portuguese energy system is used as a case study. The TIMES_PT bottom-up model was used to generate four scenarios covering the period up to 2020, corresponding to different levels of efficiency of equipment in buildings, transport and industry. In the current policy scenario, the deployment of end-use equipment follows the 2000–2005 trends and the National Energy Efficiency Action Plan targets. In the efficient scenarios, all types of equipment can be replaced by more efficient ones. Results show that aggressive demand-side options for the industry and buildings sector and the small-scale use of renewables can remove the need for the increase in large-scale renewable electricity capacity by 4.7 GW currently discussed by policy makers. Although these measures reduce total final energy by only 0–2 %, this represents reductions of 11–14 % in the commercial sector, with savings in total energy system costs of approximately 3,000 million euros2000—roughly equivalent to 2 % of the 2010 Portuguese GDP. The cost-effectiveness of policy measures should guide choices between supply shifts and demand reduction. Such balanced policy development can lead to substantial cost reductions in climate and energy policy.

The Web Service Framework for SaaS in Cloud Computing Environment

Software is also an integral part of other major ICT (information communication technology) equipment and devices, such as hardware, network, end-user communications equipment and carrier services. Recently software area has changing their using method from traditional ways to providing their process as a service. That is web service based SaaS in cloud computing. In this research, we consider the framework to process web service on SaaS, cloud computing environment. For this process, the framework has service search agent, service management mediator, UDDI server and web service inform.

Coal-based synthetic natural gas (SNG): A solution to China’s energy security and CO2 reduction?

Considering natural gas (NG) to be the most promising low-carbon option for the energy industry, large state owned companies in China have established numerous coal-based synthetic natural gas (SNG) projects. The objective of this paper is to use a system approach to evaluate coal-derived SNG in terms of life-cycle energy efficiency and CO2 emissions. This project examined main applications of the SNG and developed a model that can be used for evaluating energy efficiency and CO2 emissions of various fuel pathway systems. The model development started with the GREET model, and added the SNG module and an end-use equipment module. The database was constructed with Chinese data. The analyses show when the SNG are used for cooking, power generation, steam production for heating and industry, life-cycle energies are 20–108% higher than all competitive pathways, with a similar rate of increase in life-cycle CO2 emissions. When a compressed natural gas (CNG) car uses the SNG, life-cycle CO2 emission will increase by 150–190% compared to the baseline gasoline car and by 140–210% compared to an electric car powered by electricity from coal-fired power plants. The life-cycle CO2 emission of SNG-powered city bus will be 220–270% higher than that of traditional diesel city bus. The gap between SNG-powered buses and new hybrid diesel buses will be even larger—life-cycle CO2 emission of the former being around 4 times of that of the latter. It is concluded that the SNG will not accomplish the tasks of both energy conservation and CO2 reduction.

Test Apparatus for Performance Evaluation of Compressed Air End-Use Applications

Compressed air is an integral utility part of industrial utility systems. Any improvement in compressed air system will lead to reduction in utility cost. The effectiveness of utilization side of compressed air is usually dependent upon operator’s discretion. There are no performance testing methods available for testing existing end use equipments. A test apparatus for estimation of compressed air flow based on measurement of pressure reduction in a fixed volume cylinder in a given time is developed. The test apparatus is easy to build and simple to operate in an industrial environment. This can be used for measuring performance of any pneumatic end-use equipment and for benchmarking the performance. The test apparatus was used in a foundry for quantifying the performance of the old and new blow guns.

A numerical and experimental study of Polycyclic Aromatic Hydrocarbons in a laminar diffusion flame

During the process of biomass gasification tars are formed which exit the gasifier in vapor phase. Tar condensation creates problems like fouling and plugging of after-treatment, conversion and end-use equipment. Gasification tars consist mainly of Polycyclic Aromatic Hydrocarbons (PAHs). Former research has shown the possibilities and difficulties of tar conversion by partial combustion. Basic studies to investigate the oxidation of tars in non-premixed combustion processes are expected to give more insight in this problem. In this paper the ability of the flamelet-generated manifold (FGM) approach to numerically model multi-dimensional, laminar, non-premixed flames with the inclusion of PAH chemistry is investigated. Modeling detailed PAH chemistry requires the employment of large reaction mechanisms which lead to expensive numerical calculations. The application of a reduction technique like FGM leads to a considerable decrease (up to two orders) in the required computation time. A 1D numerical validation shows that the improvements achieved by implementing a varying Lewis number for the progress variable Y are significant for PAH species with a large Lewis number, such as C10H8. Considerable improvements are found near the flame front and on the fuel side of the flame. A comparison has been made of FGM results with qualitative Planar Laser Induced Fluorescence (PLIF) measurements. A laminar CH4/N2–air co-flow flame has been doped with two dopants, benzene and toluene, at three different concentrations. A set of filters was used in order to qualitatively distinguish the small (1–2 rings) and large (3 or more rings) aromatic species. The results show that the model is able to capture the major flame characteristics typical for PAH formation in multi-dimensional laminar non-premixed flames.

3D Rendering in the Cloud

Many modern applications and window systems perform three-dimensional (3D) rendering. For a cloud system to support such applications, that 3D rendering must be performed in the cloud, because the end-user equipment cannot be relied upon to contain the necessary rendering hardware. All systems that perform 3D rendering in the cloud are faced with two fundamental and related problems: 1) How to enable an arbitrary number of users to produce rendered pixel streams, and 2) how to transfer those pixel streams out of the server's frame buffers and into one or more encoders, for transmission to the user. We have implemented a new form of display virtualization that solves both of these problems in a low-level and transparent manner. Using our display virtualization (which we call the virtual cathode ray tube controller (VCRTC)), the cloud system can support an arbitrary number of pixel streams (bounded only by memory and bandwidth resources), and it can dynamically associate those streams with encoders. VCRTCs are completely transparent to the applications: No application needs to be modified, recompiled, or even relinked to use VCRTCs. Because they are low-level and transparent, VCRTCs are also a general mechanism with utility beyond cloud systems. © 2012 Alcatel-Lucent.

The energy-enterprise-gender nexus: Lessons from the Multifunctional Platform (MFP) in Mali

The Mali Multifunctional Platform (MFP)—a government managed, multilaterally sponsored energy program that distributed a small diesel engine attached to a variety of end-use equipment—expanded access to modern energy services and raised village incomes from 1999 to 2004. Over this period, it successfully distributed more than 500 MFPs throughout Mali, and in doing so empowered women, improved educational opportunities, and enhanced food security and community cohesion. The MFP has also motivated the government to install 1800 such platforms by the end of 2012. Based on original research interviews supplemented with an extensive literature review, this study introduces readers to the rural energy situation in Mali and describes the history of the MFP project. It then discusses the benefits the project achieved, as well as five sets of challenges the MFP faces: a growing number of non-functional platforms, lack of policy coordination, poverty, dependence on imported technology and fuel, and patriarchy. The study concludes by offering six lessons for energy development planners and practitioners.

VCSEL-based, CWDM - PON systems using reflective technology for bi-directional multi-play service provision

Orthogonal frequency division multiplexing based on radio-over-fiber schemes allows the direct use of multiple, native format wireless platforms. In combination with standard baseband provision such as Gigabit Ethernet, this provides access to a wide range of services without requiring specialized end-user equipment. However, such signals have a high laser power-bandwidth requirement which may not be a good fit to the domestic environment. Here we explore the use of low-power optical components in customer premises which interface with an intermediate optical network node. Two solutions in the context of SSMF over a CWDM optical network are described, based on either reflective or direct modulation. EVMs of better than −35 dB were achieved.

Effective Mitigation of Voltage Flicker in Power System using 12-Pulse Converter based Statcom

A Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure of end user equipments. Voltage flicker is considered as one of the most severe power quality problems caused by large time-varying loads like arc furnaces. To reduce this kind of disturbances, Static Var Compensators (SVC) has been used so far which have a limited flicker mitigation capability. In the paper, 12-pulse converter based STATCOM has been proposed for effective mitigation of Voltage flicker and reduction of total harmonic distortion in the system. All the simulations have been performed using MATLAB Software. The obtained results show that 12-pulse converter based STATCOM is very efficient and effective for the mitigation of voltage flickering and THD reduction.

Meshing power quality and electromagnetic compatibility for tomorrow's smart grid

With the onset of the smart grid, electric utilities and their customers are engaged in millions of dollars of research on smart grid technologies. There are hundreds of smart grid topics being studied by dozens of organizations including the Electric Power Research Institute (EPRI). One of the topics in the electric utility industry that has been (and still is) of significant importance to utilities is power quality (PQ). The reliable and compatible performance of end-use equipment requires, in part, quality power at the power frequencies of 50 or 60 hertz up to about 3 kHz. Compatibility with the surrounding electromagnetic environment above 3 kHz (i.e., up to 10 GHz and beyond) is also a must in today's changing environment. Electromagnetic compatibility (EMC) is paramount if electronic loads - used to operate the grid and in customer facilities - are to interoperate with the power system and other loads on the grid. This article will help the reader to understand why EMC, bundled with PQ, must be co-addressed as the smart grid takes shape in the next few decades.

Service quality evaluation in electricity utility industry: an empirical study in India

As electric utilities operate in a rapidly changing market, the role of the customer becomes important to provide quality service. Growing competition between utilities, changing legislation and increased usage of sensitive and disturbing end-user equipment are some of the reasons for increasing customer dissatisfaction. Therefore, attention needs to be diverted towards customers’ perception on quality of electricity supply and its related services so that managers can focus on specific areas of concern to improve customer satisfaction. In this paper, attempt is made for concrete and measurable improvements in the service through an extensive study on customer’s perception and various extents of the power supply. Some suggestions are provided for the improvement in service quality in Indian context.

PI and Fuzzy Logic Controller Based 3-Phase 4-Wire Shunt Active Filters for the Mitigation of Current Harmonics with the Id-IqControl Strategy

Commencing with incandescent light bulbs, every load today creates harmonics. Unfortunately, these loads vary with respect to their amount of harmonic content and their response to problems caused by harmonics. The prevalent difficulties with harmonics are voltage and current waveform distortions. In addition, Electronic equipment like computers, battery chargers, electronic ballasts, variable frequency drives, and switching mode power supplies generate perilous amounts of harmonics. Issues related to harmonics are of a greater concern to engineers and building designers because they do more than just distort voltage waveforms, they can overheat the building wiring, cause nuisance tripping, overheat transformer units, and cause random end-user equipment failures. Thus power quality is becoming more and more serious with each passing day. As a result, active power filters (APFs) have gained a lot of attention due to their excellent harmonic compensation. However, the performance of the active filters seems to have contradictions with different control techniques. The main objective of this paper is to analyze shunt active filters with fuzzy and pi controllers. To carry out this analysis, active and reactive current methods (<TEX>$i_d-i_q$</TEX>) are considered. Extensive simulations were carried out. The simulations were performed under balance, unbalanced and non sinusoidal conditions. The results validate the dynamic behavior of fuzzy logic controllers over PI controllers.

The combustion behaviour of forced-draught industrial burners when fired within the EASEE-gas range of Wobbe Index

In Europe, a common business practice for the cross-border exchange of natural gases has been formulated by EASEE-gas. The proposed range of Wobbe Index for this purpose is 48.96–56.92 MJ/Nm 3 (25 °C/0 °C, 1013.25 hPa). However, it is unclear whether the entire range of end-use equipment can accept the suggested range and still function as desired. Research is currently underway tot assess whether this range of gases can be accepted by domestic appliances. To our knowledge, there has been little systematic investigation of the acceptable range of gas quality for large-scale, forced-draught industrial burners. Although natural gas is predominantly methane with lesser amounts of higher hydrocarbons and inerts, the variation in gas composition can have significant effects on burner performance. The vast majority of forced-draught industrial burners features a flow of air independent of the gas composition, therefore the air factor is (inversely) proportional to the Wobbe Index of the gas. In this paper we present the results of experiments on a number of generic large-scale industrial burners for boilers and industrial processes in which the Wobbe Index is varied across the EASEE-gas range. The combustion effects focused mainly on flame stability (burner overheating/blow-off and vibrations) and the pollutant emissions, such as CO, NO x and unburned hydrocarbons over the desired range of turndown ratio. The experimental results showed that, for the burners studied the measured oxygen concentration was the predominant factor governing burner behaviour; between 0.5 and 7% O 2, all burners showed a stable flame while emitting less than 400 ppmv (dry, air free) CO. Outside this O 2 range, the low-NO x boiler burners, being the most sensitive, showed decreasing flame stability and increasing CO production. One burner even exhibited blow-off, causing the safety system to shut down burner operation, an undesirable event in practice. In the burners studied, the NO x emission can increase significantly with increasing Wobbe Index. Even a relatively small increase can cause the burner to exceed the locally enforced NO x limit. The visible flame length increased with increasing Wobbe Index, due to the concomitant decrease in air factor and increase in thermal input. This can lead to a higher thermal load on furnaces, which may be unacceptable in some cases. The experimental results indicate that to widen the acceptable range some form of active control is necessary for the burners for boilers. The merits of using a feed-back control system, using oxygen measurement in the flue gas, compared to a feed-forward control using the Wobbe Index of the fuel gas are discussed. In particular, aspects regarding safety in the event of sensor malfunction are seen to be important when choosing a system. In this case, the Wobbe method seems technically preferable.