Updating rail signalling systems should involve evaluating the DC systems that power
them - to ensure they provide the proper foundation for safety, explains Mathias Lang
Article from Rail Professional, October 2014
Grid Integration of Large PV Power Systems Using HVDC LinkIJERA Editor
This paper explores the interconnection of large scale Photo-Voltaic (PV) systems to the grid though a High Voltage Direct Current (HVDC) link. HVDC link is recently utilized for transmission lines longer than 50 km. It is usually utilized to interconnect two asynchronous grids with the same or different frequencies while avoiding stability disturbances greatly. A suitable Maximum Power Point Tracking (MPPT) techniques is employed to control the performance of the integrated PV system. The system of the HVDC link has two 12-pulse converter using thyristor-bridges. The delay and the extinction angles at the rectifier and the inverter units control the flow and the quantity of the transmitted power from the PV system into the grid. Fixed capacitors and filters are used to provide the AC side with the required reactive power and reduce the harmonic contents. For evaluation purposes, different simulation investigations are carried out with a detailed modeling using the MATLAB. These tests corroborate the efficacy of HVDC link for integrating large PV systems to electrical grids
Optimal Placement of Distributed Generation on Radial Distribution System for...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Grid Integration of Large PV Power Systems Using HVDC LinkIJERA Editor
This paper explores the interconnection of large scale Photo-Voltaic (PV) systems to the grid though a High Voltage Direct Current (HVDC) link. HVDC link is recently utilized for transmission lines longer than 50 km. It is usually utilized to interconnect two asynchronous grids with the same or different frequencies while avoiding stability disturbances greatly. A suitable Maximum Power Point Tracking (MPPT) techniques is employed to control the performance of the integrated PV system. The system of the HVDC link has two 12-pulse converter using thyristor-bridges. The delay and the extinction angles at the rectifier and the inverter units control the flow and the quantity of the transmitted power from the PV system into the grid. Fixed capacitors and filters are used to provide the AC side with the required reactive power and reduce the harmonic contents. For evaluation purposes, different simulation investigations are carried out with a detailed modeling using the MATLAB. These tests corroborate the efficacy of HVDC link for integrating large PV systems to electrical grids
Optimal Placement of Distributed Generation on Radial Distribution System for...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
A Review on Design and Development of high Reliable Hybrid Energy Systems wit...IJPEDS-IAES
Hybrid Energy system is a combination of two or more different types of energy resources. Now a day this hybrid energy system plays key role in various remote area power applications. Hybrid energy system is more reliable than single energy system. This paper deals with high reliable hybrid energy system with solar, wind and micro hydro resources. The proposed hybrid system cable of multi mode operation and high reliable due to non communicated based controllers (Droop Characteristic Control) are used for optimal power sharing. Size of battery can be reduced because hydro used as back up source and Maximum power point Tracking also applied to solar and wind energy systems.
Intelligent Microgrid and Distributed Generations pptMayur Hiwale
ppt is about microgrid and its evolution to intelligent microgrid. In this ppt you get know about the microgrid its architecture, advantages, disadvantages and application and implemention and also the comparison between old microgrid and new intelligent microgrid.
How HE Results In Cost Saving - an Eltek Case StudyEltek
Major UK Wireless Carriers Reduce Power Consumption and Operating
Expense with High Efficiency Power Systems from Eltek Valere
An Eltek Valere Case Study
Many carriers are realizing increasing power consumption and costs as they
move to new content- and data-oriented services and expand their wireless
networks to include 3G and 4G technologies. Managing this power consumption
is a critical initiative for these carriers to stay cost competitive. Increasingly,
carriers are evaluating power system technology as a key part of their efforts
toward making a significant impact on power consumption, because
approximately 80% of the power consumed by a telecommunications carrier
passes through these devices.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals
Dc-Dc boost converter topologies and MPPT techniques for Grid connected PV sy...rameshwar meena
1. Modeling of Dc-Dc boost converter in MATLAB Simulink.
2. MATLAB Simulink of P&O techniques and Incremental conductance.
3. Ac grid connected to solar PV array via dc-dc boost converter and Dc-Ac converter.
Operation and Control of Grid Connected Hybrid AC/DC Microgrid using Various RESIAES-IJPEDS
This paper proposes a Hybrid AC/DC Microgrid in alliance with Photo Voltaic (PV) energy, Wind Energy and Proton Exchange Membrane (PEM) Fuel cells. Microgrids are becoming increasingly attractive to the researchers because of the less greenhouse gases, low running cost, and flexibility to operate in connection with utility grid. The Hybrid AC/DC Microgrid constitutes independent AC and DC subgrids, where all the corresponding sources and loads are connected to their respective buses and these buses are interfaced using an interfacing converter. The Hybrid AC/DC Microgrid increases system efficiency by reducing the multiple reverse conversions involved in conventional RES integration to grid. A Small Hybrid AC/DC Microgrid in grid connected mode was modeled and simulated in MATLAB- SIMULINK environment. The simulation results prove the stable operation considering the uncertainty of generations and loads.
Impact of Distributed Generation on Energy LossNadineCroes
The aim is to give more insight into the effect of distributed power generation on energy loss. In most cases these distributed generators (DGs) are based on renewable energy such as solar panels and wind turbines, but there are also new technologies to increase efficiency such as the micro combined heat and power systems. Distributed generation can increase efficiency in the grid by reducing the distance between generators and consumers of electricity. The objective is to find an optimal mix of distributed generators (DGs) in a district so that energy loss is minimized and overload is avoided. The effect of using future electronic devices, such as electric vehicles, is also studied. To find an optimal mix of DGs a mixed integer quadratic programming model is defined and a case study is presented. The results indicate that the optimal solutions give substantial reductions in loss without overloading the system.
Abstract The demand for high quality electricity and growing electricity consumption has been caused by increasing electrification of daily life causes and the rising number of sensitive or critical loads. Due to the rapid increase in global energy consumption and the diminishing of fossil fuels, the customer demand for new generation capacities and efficient energy production, delivery and utilization keeps rising. The micro grid concept has the potential to solve major problems arising from large penetration of distributed generation in distribution systems. A proper control strategy should be implemented for a successful operation of a micro grid . Different load models can be simulated and analyzed using MATLAB and PSCAD software. In this paper, the work done in the field of Micro Grid has been reviewed. Keywords: DER, MG, PCC, PV, VSI.
Power flow control of hybrid micro grids using modified uipcAsoka Technologies
Neuro Fuzzy Inference System (ANFIS) controlled modified Unified Inter-Phase Power Controller (UIPC). For study, a classic hybrid micro-grid connected to grid comprising of a AC micro-grid and a DC micro-grid is taken into account. These micro-grids are interconnected employing a modified UIPC, rather than using the power converters connected in parallel. As the first input of this paper is the standard structure of UIPC, which used three power converters in every phase. It was then modified such as number of power converters is used less and implemented for the control of the exchange of power between AC-DC microgrids. In every phase there is one power electronic converter in the improved structure. It is called as Line Power Converter (LPC). Also there is Bus Power Converter (BPC) to regulate the voltage of the DC bus. The Line Power Converters links the AC micro-grid to the main grid. The DC buses are also linked with them. It can be operated in Inductance Mode (IM) as well as Capacitance Mode (CM). The control structure of LPCs has an Adaptive Fuzzy Logic Controller in it. For hybrid micro-grids, the capability of the suggested power flow control strategy is confirmed by the MATLAB simulation results.
The hybrid AC/DC microgrid is considered to be the more and more popular in power systems as increasing DC loads. In this study, it is presented that a hybrid AC/DC microgrid is modelled with some renewable energy sources (e.g. solar energy, wind energy), typical storage facilities (e.g. batteries), and AC, DC load, and also the power could be transformed smoothly between the AC and DC sub-grids by the bidirectional AC/DC converter. Meanwhile, coordination control strategies are proposed for power balance under various operations. In grid-connected mode, the U–Q (DC bus voltage and reactive) or PQ method is adopted for the bidirectional AC/DC converter according to the amount of exchange power between AC and DC system in order to improve the DG utilisation efficiency, protecting the converter and maintain the stable operation of the system. In islanded mode, V/F control is applied to stabilising the entire system voltage and frequency, achieving the power balance between the AC and DC systems. Finally, these control strategies are verified by simulation with the results showing that the control scheme would maintain stable operation of the hybrid AC/DC microgrid.
A Review on Design and Development of high Reliable Hybrid Energy Systems wit...IJPEDS-IAES
Hybrid Energy system is a combination of two or more different types of energy resources. Now a day this hybrid energy system plays key role in various remote area power applications. Hybrid energy system is more reliable than single energy system. This paper deals with high reliable hybrid energy system with solar, wind and micro hydro resources. The proposed hybrid system cable of multi mode operation and high reliable due to non communicated based controllers (Droop Characteristic Control) are used for optimal power sharing. Size of battery can be reduced because hydro used as back up source and Maximum power point Tracking also applied to solar and wind energy systems.
Intelligent Microgrid and Distributed Generations pptMayur Hiwale
ppt is about microgrid and its evolution to intelligent microgrid. In this ppt you get know about the microgrid its architecture, advantages, disadvantages and application and implemention and also the comparison between old microgrid and new intelligent microgrid.
How HE Results In Cost Saving - an Eltek Case StudyEltek
Major UK Wireless Carriers Reduce Power Consumption and Operating
Expense with High Efficiency Power Systems from Eltek Valere
An Eltek Valere Case Study
Many carriers are realizing increasing power consumption and costs as they
move to new content- and data-oriented services and expand their wireless
networks to include 3G and 4G technologies. Managing this power consumption
is a critical initiative for these carriers to stay cost competitive. Increasingly,
carriers are evaluating power system technology as a key part of their efforts
toward making a significant impact on power consumption, because
approximately 80% of the power consumed by a telecommunications carrier
passes through these devices.
IJERA (International journal of Engineering Research and Applications) is International online, ... peer reviewed journal. For more detail or submit your article, please visit www.ijera.com
Welcome to International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals
Dc-Dc boost converter topologies and MPPT techniques for Grid connected PV sy...rameshwar meena
1. Modeling of Dc-Dc boost converter in MATLAB Simulink.
2. MATLAB Simulink of P&O techniques and Incremental conductance.
3. Ac grid connected to solar PV array via dc-dc boost converter and Dc-Ac converter.
Operation and Control of Grid Connected Hybrid AC/DC Microgrid using Various RESIAES-IJPEDS
This paper proposes a Hybrid AC/DC Microgrid in alliance with Photo Voltaic (PV) energy, Wind Energy and Proton Exchange Membrane (PEM) Fuel cells. Microgrids are becoming increasingly attractive to the researchers because of the less greenhouse gases, low running cost, and flexibility to operate in connection with utility grid. The Hybrid AC/DC Microgrid constitutes independent AC and DC subgrids, where all the corresponding sources and loads are connected to their respective buses and these buses are interfaced using an interfacing converter. The Hybrid AC/DC Microgrid increases system efficiency by reducing the multiple reverse conversions involved in conventional RES integration to grid. A Small Hybrid AC/DC Microgrid in grid connected mode was modeled and simulated in MATLAB- SIMULINK environment. The simulation results prove the stable operation considering the uncertainty of generations and loads.
Impact of Distributed Generation on Energy LossNadineCroes
The aim is to give more insight into the effect of distributed power generation on energy loss. In most cases these distributed generators (DGs) are based on renewable energy such as solar panels and wind turbines, but there are also new technologies to increase efficiency such as the micro combined heat and power systems. Distributed generation can increase efficiency in the grid by reducing the distance between generators and consumers of electricity. The objective is to find an optimal mix of distributed generators (DGs) in a district so that energy loss is minimized and overload is avoided. The effect of using future electronic devices, such as electric vehicles, is also studied. To find an optimal mix of DGs a mixed integer quadratic programming model is defined and a case study is presented. The results indicate that the optimal solutions give substantial reductions in loss without overloading the system.
Abstract The demand for high quality electricity and growing electricity consumption has been caused by increasing electrification of daily life causes and the rising number of sensitive or critical loads. Due to the rapid increase in global energy consumption and the diminishing of fossil fuels, the customer demand for new generation capacities and efficient energy production, delivery and utilization keeps rising. The micro grid concept has the potential to solve major problems arising from large penetration of distributed generation in distribution systems. A proper control strategy should be implemented for a successful operation of a micro grid . Different load models can be simulated and analyzed using MATLAB and PSCAD software. In this paper, the work done in the field of Micro Grid has been reviewed. Keywords: DER, MG, PCC, PV, VSI.
Power flow control of hybrid micro grids using modified uipcAsoka Technologies
Neuro Fuzzy Inference System (ANFIS) controlled modified Unified Inter-Phase Power Controller (UIPC). For study, a classic hybrid micro-grid connected to grid comprising of a AC micro-grid and a DC micro-grid is taken into account. These micro-grids are interconnected employing a modified UIPC, rather than using the power converters connected in parallel. As the first input of this paper is the standard structure of UIPC, which used three power converters in every phase. It was then modified such as number of power converters is used less and implemented for the control of the exchange of power between AC-DC microgrids. In every phase there is one power electronic converter in the improved structure. It is called as Line Power Converter (LPC). Also there is Bus Power Converter (BPC) to regulate the voltage of the DC bus. The Line Power Converters links the AC micro-grid to the main grid. The DC buses are also linked with them. It can be operated in Inductance Mode (IM) as well as Capacitance Mode (CM). The control structure of LPCs has an Adaptive Fuzzy Logic Controller in it. For hybrid micro-grids, the capability of the suggested power flow control strategy is confirmed by the MATLAB simulation results.
The hybrid AC/DC microgrid is considered to be the more and more popular in power systems as increasing DC loads. In this study, it is presented that a hybrid AC/DC microgrid is modelled with some renewable energy sources (e.g. solar energy, wind energy), typical storage facilities (e.g. batteries), and AC, DC load, and also the power could be transformed smoothly between the AC and DC sub-grids by the bidirectional AC/DC converter. Meanwhile, coordination control strategies are proposed for power balance under various operations. In grid-connected mode, the U–Q (DC bus voltage and reactive) or PQ method is adopted for the bidirectional AC/DC converter according to the amount of exchange power between AC and DC system in order to improve the DG utilisation efficiency, protecting the converter and maintain the stable operation of the system. In islanded mode, V/F control is applied to stabilising the entire system voltage and frequency, achieving the power balance between the AC and DC systems. Finally, these control strategies are verified by simulation with the results showing that the control scheme would maintain stable operation of the hybrid AC/DC microgrid.
Con el Curso Cómo analizar unas bases para preparar una propuesta para una Licitación, conoce toda la documentación, requisitos técnicos, legales, administrativos y económicos para participar en una licitación con el Gobierno.
Con el Curso de Bitácora Electrónica de Obra Pública (BEOP) aprenderás los fundamentos legales, así como el uso del sistema y resolverás tus dudas sobre el Sistema de Bitácora Electrónica.
Con el Curso de Estrategias de Marketing usando Internet tendrás un panorama de lo que puedes hacer para aprovechar Internet para hacer mercadeo de tu negocio.
¿Quieres aprender a participar en licitaciones electrónicas en Compranet 5.0?
¿Cómo realizar preguntas para la junta de aclaraciones, enviar tus propuestas Técnica y Económica a la plataforma Compranet 5.0?
Aprende como utilizar la normatividad a tu favor en licitaciones electrónicas con Compranet 5.0.
Incluye SUBASTAS (OSD).
Con el Curso de CompraNet 5.0 para Convocantes, sabrás todo el proceso para publicar y dar seguimiento a procedimientos de contratación en CompraNet 5.0, aprenderás la manera de subir las propuestas que se entregan de manera presencial en licitaciones mixtas o presenciales por mandato del acuerdo normativo de Junio de 2011.
High Step-Up Converter with Voltage Multiplier Module for Renewable Energy Sy...IJRES Journal
In this project, A novel high step-up converter, which is suitable for renewable energy system, is proposed.Through a voltage multiplier module composed of switched capacitors and coupled inductors, a conventional interleaved boost converter obtains high step-up gain without operating at extreme duty ratio.The configuration of the proposed converter not only reduces the current stress but also constrains the input current ripple, which decreases the conduction losses and lengthens the lifetime of the input source. In addition, due to the lossless passive clamp performance, leakage energy is recycled to the output terminal. Hence, large voltage spikes across the main switches are alleviated, and the efficiency is improved.
High Step-Up Converter with Voltage Multiplier Module for Renewable Energy Sy...irjes
In this project, A novel high step-up converter, which is suitable for renewable energy system, is proposed.Through a voltage multiplier module composed of switched capacitors and coupled inductors, a conventional interleaved boost converter obtains high step-up gain without operating at extreme duty ratio.The configuration of the proposed converter not only reduces the current stress but also constrains the input current ripple, which decreases the conduction losses and lengthens the lifetime of the input source. In addition, due to the lossless passive clamp performance, leakage energy is recycled to the output terminal. Hence, large voltage spikes across the main switches are alleviated, and the efficiency is improved.
A Power quality problem is an occurrence of nonstandard voltage, current or frequency that results in a
failure or a misoperation of end user equipments. Utility distribution networks, sensitive industrial loads and
critical commercial operations suffer from various types of outages and service interruptions which can cost
significant financial losses. With the increase in load demand, the Renewable Energy Sources (RES) are
increasingly connected in the distribution systems which utilizes power electronic Converters/Inverters. This
paper presents a single-stage, three-phase grid connected solar photovoltaic (SPV) system. The proposed system
is dual purpose, as it not only feeds extracted solar energy into the grid but it also helps in improving power
quality in the distribution system. The presented system serves the purpose of maximum power point tracking
(MPPT), feeding SPV energy to the grid, harmonics mitigation of loads connected at point of common coupling
(PCC) and balancing the grid currents. The SPV system uses a three-phase voltage source converter (VSC) for
performing all these functions. An improved linear sinusoidal tracer (ILST)-based control algorithm is proposed
for control of VSC. In the proposed system, a variable dc link voltage is used for MPPT. An instantaneous
compensation technique is used incorporating changes in PV power for fast dynamic response. The SPV system
is first simulated in MATLAB along with Simulink and simpower system toolboxes.
How to Reduce Total Cost of Ownership of 4G-LTE Networks - an Eltek White PaperEltek
How six features and capabilities of DC power systems can lower the total cost of ownership of 4G/LTE networks. Published February 2014.
Carriers spend an estimated $36 billion globally on energy expense to keep wireless base stations online. That includes $21.9 billion in grid power, according to ABI Research, and another $14.6 million in gasoline and diesel for gen-sets according to the GSMA. That cost has risen dramatically in recent years as energy prices continue to climb and the number of base stations increases.
The high cost of energy explains why the use of alternative energies to power base stations is on the rise. But it doesn’t explain why some carriers focus solely on getting the lowest capital cost in procuring the DC power systems that manage this power. There has been so much innovation in recent years that DC power systems are far from being commodity purchases.
Given this new technology, a total cost of ownership analysis for buying new systems is a balanced way to consider the purchase price and the ongoing cost elements. With a two to five-year payback on these systems, and a ten- year or longer useful life, it could be argued that maximizing these cost-saving features is even more important than seeking a lower capital cost.
This whitepaper will look at the key ways that a DC power system can save money for wireless carriers, including high efficiency, support for alternative energy, intelligent monitoring power density and design for reliability.
A REVIEW ON IMPLEMENTATION OF THREE-PHASE TWO-STAGE GRID-CONNECTED MICijiert bestjournal
Module integrated converters (MICs) in single phase have witnessed recent market success due to unique features such as improved energy harvest,improved system efficiency,lower installation costs,plug - and - play operation,and enhanced flexibility and mo dularity. The MIC sector has grown from a niche market to mainstream,especially in the United States. Assuming further expansion of the MIC market,this paper presents the micro inverter concept incorporated in large size photovoltaic (PV) installations such as megawatts (MW) - class solar farms where a three - phase ac connection is employed. A high - efficiency three - phase MIC with two - stage zero voltage switching (ZVS) operation for the grid - tied PV system is proposed which will reduce cost per watt,improve re - liability,and increase scalability of MW - class solar farms through the development of new solar farm system architectures. The first stage consists of a high - efficiency full - bridge LLC resonant dc � dc converter which interfaces to the PV panel and prod uces a dc - link voltage.
Smart Power Transmission System Using FACTS DeviceIJAPEJOURNAL
Making of smart grids puts mounting pressure on the nation’s aging electric power transmission system. Just planting additional towers and stringing more line won’t practice the nation’s electric power transmission infrastructure to meet up the energy challenges ahead. Smart grids stand geared up to play a much larger role in the energy equation for reduction of transmission line losses. The FACTS controllers come out with the capability of enhancing transmission system control, reliability, and operation. This paper will discuss and express how Static Synchronous Compensator (STATCOM) has effectively been applied to power system for efficiently regulating system voltage and thus increase system load ability. This paper investigates the effects of (STATCOM) on voltage stability of a power system at different positions.The simulation analysis of this paper can be used as guideline for power industry. The study is thereby simulated using the MATLAB/SIMULINK software and simulation results show that STATCOM is effective in midpoint voltage regulation on transmission line. In this paper comparison is also performed between STATCOM and SVC under fault condition and it is proved that STATCOM have the capacity to provide more capacitive power for the period of a fault than SVC.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
This report aims to familiarize the reader with basic but important information about
two specific types of controllers – DC drives and AC drives. The first part provides
descriptions of the general working principles of variable speed drive (VSD)
technology. It discusses their main advantages and disadvantages between AC and
DC drive solutions. The second part explains some problems that could possibly be
encountered when employing AC or DC drive systems and offers practical
recommendations about how to approach these problems.
Dr Adrian West, Optima’s technical director, has spent more than 30 years working
with, programming and troubleshooting drive systems. This report is based on his
extensive practical knowledge and experience. It is, therefore, a very accurate and independent source of information.
SIMULATION AND ANALYSIS OF TIBC FOR INDUCTION MOTOR DRIVEEditor IJMTER
This project proposes a new low cost converter- inverter drive system for induction motor.
The converter is designed to drive a three-phase induction motor directly from PhotoVoltaic (PV)
energy source. The three phase induction motor is better because of its low cost, reliability, no
maintenance, high efficiency and good power factor. Two Inductor Boost Converter (TIBC) is used
in first stage along with the voltage doubler rectifier and snubber to develop the system. The reason
to choose TIBC is due to its high voltage gain and low input current ripple, which minimizes the
oscillations at the module operation point. To convert the boosted DC output voltage from PV
module into AC, a voltage source inverter is implemented to attain sufficient voltage to drive the
motor. As the PV cell posses the nonlinear behaviour, the Maximum Power Point Tracker (MPPT)
controller is needed to improve the utilization efficiency of the converter. The MPPT algorithm
proposed in this paper based on hill climbing algorithm, for matching the load and to boost the PV
module output voltage. PI Controller is used to control the speed of the Induction Motor. The entire
system is simulated using Matlab Simulink environment. The system is expected to be operated with
high efficiency and low cost for long lifetime.
Applications of Smart Grid through Harmonic Current & Reactive Power Compensa...IJMTST Journal
Power factor correction (PFC) is a mandatory functionality of electronic products in the industrial and commercial market in order to mitigate grid harmonics and operate a power system economically. Since the load characteristics of most PFC applications such as home appliances, battery chargers, switched mode power supplies and other digital products support unidirectional power flow, the general ac-dc boost converter with step-up chopper is considered a popular topology. This is because they are low cost, simple, and their performance is well-proven. Its main task inside the system is to maintain dc-link voltage constantly in order to feed loads at different power ratings. In addition, it is necessary to control input current with a pure sinusoidal waveform in phase with input voltage. Active power filters (APF) are another approach capable of improving grid power quality. Many research endeavors have included APFs in their circuit topologies and control strategies. Unlike PFC circuits, the APF is a system in itself which provides compensation of harmonics and reactive power in order to reduce undesirable effects from non-linear loads and uncontrolled passive loads in power systems.
The energy consumption of urban railway stations is very large and ever increasing. To reduce the national electrical grid consumption, the first step is optimizing the equipment size and the second step is adding other available electrical sources like the train residual braking energy. Many of local energies productions use Direct Current (DC. The actual internal station grid is in Alternative Current (AC) but the majority of the equipment has an AC/DC converter to be supplied in DC. This paper describes the project led by Efficacity Institute, which addresses the use of additional existing energies and to develop a more adapted station grid to reducing the daily energy consumption peak. One Efficacity energetic concept aims to store the braking energy of the trains with a stationary electrical saving system. This energy is integrated to the power supply of a railway station thanks to a micro grid. First step of this micro grid are studied in this paper to develop the more adapted grid structure
Set course for lower cost of ownership
An Eltek Modular UPS, designed and certified for marine use, is the secure and safe way to improve the efficiency and flexibility of onboard power supplies. It will significantly reduce complexity, increase control and manageability, and provide the basis for a future-proof on board power infrastructure.
The bottom line is a significant reduction in total cost of ownership.
Utviklingen av smarte nett krever også utvikling av smarte komponenter. Eltek i Drammen har tatt ballen og utvikler en kompekt strømomformer for kostnadseffektive energilagringstjenester.
Artikkel om Eltek i Energiteknikk nr6 sept2015.
www.eltek.com
Faksimile fra Drammens Tidende 22. oktober 2014.
Folk flest forstår ikke hvilken avansert teknologiutvikling som skjer i Drammen mener Eltek.
Mandag fikk bedriften på Eikhaugen i Drammen sjansen til å fortelle ansatte i Nærings- og fiskeridepartementet om den teknologiutvikling som skjer i Drammen.
– Jeg tror ikke helt Drammen forstår hvor avansert teknologiutviklingen som foregår i Kobbervikdalen er, sier markedsdirektør Morten Schøyen.
Eltek er en verdensledende bedrift innen strømforsyning til telekom, og har blant annet utviklet solcelleanlegg til erstatning eller tillegg til dieselanlegg for å drifte mobilmaster i land som mangler strømforsyning.
Som et eksempel tar Eltek fram at det ventede forbruket av diesel for å drifte de økende antall telekom-tårnene i Myanmar i år 2017 kunne reduseres med volumet av 30 fulle OL-svømmebasseng.
Også Drammen Næringslivsforening fikk et slikt besøk.
Det høyteknologiske naboskapet på Eikhaugen viser at verdensledende bedrifter kan lykkes fra adresser i Drammen.
Elteks ansatte har hele verden som tumleplass og hele kloden på kontoret. Men innovasjonsdirektøren reiser helst
virtuelt. For Satvir Singh Parmar (35) vil hjem til middag.
Faksimile fra Drammens Tidende fredag 3. oktober
Boost and equalize charge with limited voltage window - an Eltek White PaperEltek
Designing a DC system requires consideration of the ability to work within a certain DC voltage
window. The maximum voltage provides the high-end of a voltage range that is available to
charge the battery, whereas, the minimum voltage gives the lowest voltage within that range that
is acceptable to the system so that the battery can be discharged.
It is not unusual for this voltage window to be very narrow, where specifications can be as close
as +/- 10% from the nominal DC voltage.
This limited system voltage window can be a challenge to take into consideration when
designing a DC system, especially when using it with Ni-Cd back up batteries that have a wide
voltage window. What is needed is a boost or equalize charge to reach the maximum voltage
that is effective for the attached batteries.
This paper will present a different system designed to
Eltek skal være med å levere 300 solcelledreven
basestasjoner i den arabiske gulfregionen.
– Det er blant de største kontraktene innenfor dette feltet, sier Eltek-direktør Morten Schøyen.
Tett samarbeid mellom to teknologibedrifter som holder til i
Kobbervikdalen førte til at «lillebroren» vant en prestisjetung industripris.
Faksimilie fra Drammens Tidende Frefdag 29. august 2014
Eltek and our Americas Region President Allen Pitts named as one of the 2014 industry game changers. Published in June 2014, this is the third in a series of three interviews.
"Those who influence with knowledge and character rather than a big booming voice. Those who know their area of expertise like the back of their hands WHILE they constantly seek to learn and conquer new opportunities across the telecom industry. Game Changers are those who lead by example and walk their talk."
Om Entra eller Flytoget blir privatisert eller ikke betyr lite for Norge.
Det viktige er hvordan vi skaper fremtidens eksportsuksesser,
skriver Satvir Singh Parmar i Eltek.
Debatten etter regjeringens
eierskapsmelding er forutsigbar og
dreier seg om prosenter og eierandeler
i bedrifter som er et resultat
av gårsdagens innovasjon, forskning
og utvikling.
Cost Saving and Excellent Payback for US Exchange Carrier - an Eltek Case S...Eltek
Switching to Eltek Valere’s Scalable DC Power System Delivers Excellent Payback for Leading Local Exchange Carrier
Scalable DC power solutions provide efficiency, flexibility and space savings resulting in excellent ROI and short payback period
Telecom network power systems are some of the most durable systems in a central office (CO) – sometimes lasting for decades. But when these systems start to fail and replacement or maintenance costs begin to rise, it is time to evaluate the costs of ongoing repair versus replacement. This is the situation in which a large U.S. local exchange carrier found itself with nearly a dozen of its central offices across the country.
This Eltek Valere customer is one of the largest local exchange carriers in the United States and provides local, long distance, high-speed data and wireless services to both residential and business customers.
High Effiency Power Solutions for Next Generation Small Cell Networks - An El...Eltek
The growth of the mobile Internet has been more dramatic than any pundit could have imagined. Fueled by the iPhone and other smartphones, enthusiastic mobile Internet users have turned to email, video, Internet surfing and mobile apps in such overwhelming numbers that several significant network crashes have occurred. This has spurred carriers to quickly update their networks on two fronts: first, by moving to 4G high-speed wireless technology, which is specifically designed to support mobile Internet use; and second, by augmenting existing macrocells with small cells to bring coverage to wherever users are.
Monitoring of Lead Acid Batteries - an Eltek White PaperEltek
Eltek's Gunnar Hedlund demonstrates different methods of predicting premature capabity loss in your battery park.
No foolproof indicators/tools for knowing and predicting the health and life of a lead acid battery have been evolved or devised. The only way to truly determine the health of a standby lead-acid battery is to perform a 100 % capacity test, according to the battery manufacturers discharge table.
Such a capacity test means that the battery needs to be disconnected from the load and another back-up battery connected when the capacity test is performed. However, comprehensive controllers and instruments are now able to find failing cells without this test and while the battery system is online.
A large number of techniques have been explored and tried out in the field. No single method or test instrument is capable of foolproof prediction about the residual capacity without performing a 100% capacity test. On the other hand, by combining some of them the state of health and expected residual life of the battery can be predicted more precisely and reliably. This is especially true in the finding of failing cells in a standby lead-acid battery.
Eltek and our Americas Region President Allen Pitts named as one of the 2014 industry game changers in this article published in February 2014.
"Those who influence with knowledge and character rather than a big booming voice. Those who know their area of expertise like the back of their hands WHILE they constantly seek to learn and conquer new opportunities across the telecom industry. Game Changers are those who lead by example and walk their talk."
DevOps and Testing slides at DASA ConnectKari Kakkonen
My and Rik Marselis slides at 30.5.2024 DASA Connect conference. We discuss about what is testing, then what is agile testing and finally what is Testing in DevOps. Finally we had lovely workshop with the participants trying to find out different ways to think about quality and testing in different parts of the DevOps infinity loop.
Search and Society: Reimagining Information Access for Radical FuturesBhaskar Mitra
The field of Information retrieval (IR) is currently undergoing a transformative shift, at least partly due to the emerging applications of generative AI to information access. In this talk, we will deliberate on the sociotechnical implications of generative AI for information access. We will argue that there is both a critical necessity and an exciting opportunity for the IR community to re-center our research agendas on societal needs while dismantling the artificial separation between the work on fairness, accountability, transparency, and ethics in IR and the rest of IR research. Instead of adopting a reactionary strategy of trying to mitigate potential social harms from emerging technologies, the community should aim to proactively set the research agenda for the kinds of systems we should build inspired by diverse explicitly stated sociotechnical imaginaries. The sociotechnical imaginaries that underpin the design and development of information access technologies needs to be explicitly articulated, and we need to develop theories of change in context of these diverse perspectives. Our guiding future imaginaries must be informed by other academic fields, such as democratic theory and critical theory, and should be co-developed with social science scholars, legal scholars, civil rights and social justice activists, and artists, among others.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
"Impact of front-end architecture on development cost", Viktor TurskyiFwdays
I have heard many times that architecture is not important for the front-end. Also, many times I have seen how developers implement features on the front-end just following the standard rules for a framework and think that this is enough to successfully launch the project, and then the project fails. How to prevent this and what approach to choose? I have launched dozens of complex projects and during the talk we will analyze which approaches have worked for me and which have not.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Key Trends Shaping the Future of Infrastructure.pdfCheryl Hung
Keynote at DIGIT West Expo, Glasgow on 29 May 2024.
Cheryl Hung, ochery.com
Sr Director, Infrastructure Ecosystem, Arm.
The key trends across hardware, cloud and open-source; exploring how these areas are likely to mature and develop over the short and long-term, and then considering how organisations can position themselves to adapt and thrive.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024
The power behind the signal
1. October 2014 Page 91
October 2014 Page PB
Signalling
Updating rail signalling systems should involve evaluating the DC systems that power
them - to ensure they provide the proper foundation for safety, explains Mathias Lang
The growth of the rail system in
Britain is leading to expanded
routes and system-wide
updates and improvements.
For many operators this also
represents an opportunity to revisit their
rail signalling systems, as well as the DC
power systems that support them, to
ensure that these foundational systems
reliably and effectively improve rail
safety.
For while the railways are
extremely safe, the increase in train
cars and passengers combined with
aging equipment and new conductor
distractions means there is no room for
complacency.
Many operators are upgrading their
rail signalling systems. An example of this
is Great Western’s plans to spend £350
million to upgrade 1960’s-era signalling
technology on its main line. The project is
part of a broader £5 billion plan to expand
services on the main line to accommodate
more travellers.
A lot has changed since the 1960’s, and
one of the significant technology updates
has been to the power systems that are
critical to signalling system upgrades.
DC power systems consist of a rectifier
that converts AC power from the mains
to the DC power that is needed by the
equipment. There’s also a back-up power
that can use batteries or diesel generators.
The two are tied together via a controller
that monitors system health and battery
back-up health and can charge the
batteries and switch between mains and
back-up power system when needed.
The power behind
the signal
2. October 2014 Page 93
Signalling
Time to change
Just like Great Western, many rail systems made their DC power system technology selections decades ago, and put in place rock-solid, if hard to manage, systems based on silicon-controlled rectifier (SCR) technology that has served railway systems well for many years.
At that time SCR power conversion systems were getting competition from switched-mode rectifier (SMR) technology, which had just entered the market and had great advantages in terms of power conversion efficiency, lighter weight and small size. But SCR power systems had better performance and offered the best reliability at the time and became the de facto choice for railroads worldwide.
Fast forward to today and SMR power systems are used widely in the telecom and other industries, and technology improvements have eliminated all of the initial performance challenges. This technology is now a viable choice for rail signalling systems thanks to its modularity, redundancy and high efficiency.
Modularity provides flexibility and redundancy
The modularity of SMR systems is due to their small size and light weight and has resulted in system flexibility and cost-effective redundancy, resulting in dramatically improved reliability. This modularity means that if a 100-amp system is needed at a site, an SMR power shelf might provide that power through two 50A rectifier modules that operate in parallel to provide the total required power. A third 50A module could be added in back-up mode in the event that one of the two main rectifiers failed. This approach contrasts with monoblock power systems, in which a single rectifier provides the entire power load, with redundancy provided by a second, complete 100A rectifier.
Generally, a modular system is less expensive. It also adds flexibility that is demonstrated by the ability to expand the capacity of a DC power system to accommodate new equipment, by adding new rectifier modules to a power shelf instead of replacing an entire monoblock system with a new, higher power system.
Redundancy
Redundancy is a key issue in maximizing power system uptime. Modular systems provide N+1 redundancy; meaning only one module is required to back up all of the (N) modules in a power shelf. When the system detects a failure in a rectifier module it will immediately switch over to the back-up module without an interruption in service.
SMR power modules weigh between four and 10 pounds and each one is hot swappable, so that a repairperson can replace that module without any downtime. System controllers automatically recognise the new module and it starts to pick up its share of the load immediately. This dramatically lowers mean time to repair (MTTR) to less than 10 minutes.
High efficiency reduces cost and impact on environment
All industries today are looking to be good corporate citizens and save on energy costs. Choosing a high-efficiency SMR DC power system technology to use for signalling systems will reduce power consumption and lower the impact on the environment for rail operators.
Best-in-class SMR technology has an AC-to-DC power conversion efficiency level of up to 95 per cent. What this means is that as the AC power comes into the system from the mains, only five per cent of that energy is lost (typically as heat) in the AC-to-DC conversion process.
Here’s an example of how high- efficiency can reduce energy loss. Assume the case of a 125V, 100A DC power system that is 85 per cent efficient, but that is operating at 50 per cent of its capacity. That means its output is 6250W (125V x 50A).
To generate 6250W of output, an 85 per cent efficient charger requires 7353W of input. That means 1103W are wasted in the conversion process. And those wasted watts are lost in the form of heat; that is nearly 4000 BTU/hour, which will mean additional costs for air condition or air movement system to keep the overall system cool.
Compare that energy utilisation to a 95 per cent efficiency power system with the same capacity and you see that you only need 6578W of AC input to get the necessary 6250W of DC output. The losses have been cut to 328W - a reduction in waste of about 70 per cent versus the low-efficiency system.
Not only does this save money for rail operators, but the reduced energy consumption also contributes significantly to reducing carbon emissions.
Safety most important
Rail safety is the most important job of today’s rail operators, and many are revisiting their decades-old systems and looking to update them. When updating rail signalling systems it’s important to consider the system holistically and to evaluate the DC power systems that power them, to ensure they offer modularity, redundancy and high efficiency - and thus provide the proper foundation for safety.
Mathias Lang is segment manager for Rail & Metro
at Eltek
Visit www.eltek.com
The modularity of SMR systems is due to their small size and light weight and has resulted in system flexibility and cost-effective redundancy, resulting in dramatically improved reliability