702 research outputs found
Design guide for outdoor AC substation earthing systems, with specific application to Eskom Bloemfontein distributor's requirements
ThesisIn modern high voltage substations, earthing has become
one of the dominant problems of AC power system design.
In order to understand the theoretical background and
problems associated with earthing system design, various
international guides were investigated and scrutinised.
This investigation of the theory led to the analysis of
general methods and techniques used for earthing system
design.
Due to the lack and short supply of human expertise in
earthing system design, a computer program was developed
on a Personal Computer, to help enhance and distribute
the needed expertise .
The purpose of this thesis is to provide a complete,
pract i cal and scientific step-by- step guideline to design
a safe and effective outdoor AC substation earthing
system
Service continuity in complex power systems: safety, operation and maintenance
The research aims to define electrical architectures based on the rationalization of the distribution structure and of power sources with the achievement of the primary objectives of service continuity, power quality, safety and safe maintenance.
The thesis consists of two parts: the first part deals with the architecture impact on a complex system analyzing the system configuration and operational safety aspects. New developments and methodologies are presented in the study of critical systems. A theory of complex systems for safety, operation and maintenance aspects is defined that enables to assist the management of the system throughout its whole life cycle and allows an implementation of programming languages.
The second part refers to specific issues of mission critical power systems, data centers and hospitals especially. Several measurements were performed in laboratory and on field to analyze sneaky critical cases for the service continuity and the integrity of these strategic power systems.The research aims to define electrical architectures based on the rationalization of the distribution structure and of power sources with the achievement of the primary objectives of service continuity, power quality, safety and safe maintenance. The thesis consists of two parts: the first part deals with the architecture impact on a complex system analyzing the system configuration and operational safety aspects. New developments and methodologies are presented in the study of critical systems. A theory of complex systems for safety, operation and maintenance aspects is defined that enables to assist the management of the system throughout its whole life cycle and allows an implementation of programming languages. The second part refers to specific issues of mission critical power systems, data centers and hospitals especially. Several measurements were performed in laboratory and on field to analyze sneaky critical cases for the service continuity and the integrity of these strategic power systems
Solar Decathlon Africa: Building Envelope Design
The goal of this project was to create an innovative net zero energy building envelope design and construction health and safety plan for Team OCULUS of the Solar Decathlon Africa 2019 Competition. The design consisted of developing an envelope assembly that blended practical and innovative materials and attachment configurations. In addition, a construction site safety plan was generated to protect all personnel who enter the site during the construction phase. The building envelope group of Team OCULUS has provided an original design that incorporates local construction materials, Moroccan architecture, and makes energy conservation a priority. The result was an adaptable and sustainable envelope design and construction drawings for the Solar Decathlon Competition
Understanding and Quantifying Arc Flash Hazards in the Mining Industry
Arc flash generally refers to the dangerous exposure to thermal energy released by an arcing fault on an electrical power system, and in recent years, arc flash hazards have become a prominent safety issue in many industries. This problem however, has not been effectively addressed in the mining industry. MSHA data for the period 1990 through 2001 attributes 836 injuries to non-contact electric arc burns , making it the most common cause of electrical injury in mining. This paper presents results from several elements of a recent NIOSH study of arc flash hazards in mining, and provides information and recommendations that can help reduce these injuries. Characteristics of past arc flash injuries in mining are first outlined, such as the electrical components and work activities involved (based on MSHA data). This is followed by a review of important concepts and terminology needed to understand this hazard. Next, methods for identifying, measuring, and managing arc flash hazards on a power system are covered, with emphasis on recommendations found in NFPA 70E, Standard for Electrical Safety in the Workplace. Finally, results are presented from a detailed arc flash hazard analysis performed on a sample mine electrical power system using IEEE 1584-2004a, focusing on components and locations presenting severe hazards as well as engineering solutions for reducing the risk to personnel. Index terms - electrical arcing, electrical burns, mining, arc flash hazard analysis2007835
Multi-KW dc distribution system technology research study
The Multi-KW DC Distribution System Technology Research Study is the third phase of the NASA/MSFC study program. The purpose of this contract was to complete the design of the integrated technology test facility, provide test planning, support test operations and evaluate test results. The subjet of this study is a continuation of this contract. The purpose of this continuation is to study and analyze high voltage system safety, to determine optimum voltage levels versus power, to identify power distribution system components which require development for higher voltage systems and finally to determine what modifications must be made to the Power Distribution System Simulator (PDSS) to demonstrate 300 Vdc distribution capability
Estudio energético y diseño de una instalación fotovoltaica aislada sobre cubierta para la empresa Glazura s.r.o en la República Checa
Treball Final de Grau en Enginyeria Elèctrica. Codi: EE1045. Curs acadèmic 2013-2014The objective of this project is to do an energetic study of the Company Glazura s.r.o. where is
going to be studied all the production processes and all the machines taking part of the
process, and the transformers and the compressors to try to do as much improvements as
possible
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Photovoltaic power systems and the National Electrical Code: Suggested practices
This guide provides information on how the National Electrical Code (NEC) applies to photovoltaic systems. The guide is not intended to supplant or replace the NEC; it paraphrases the NEC where it pertains to photovoltaic systems and should be used with the full text of the NEC. Users of this guide should be thoroughly familiar with the NEC and know the engineering principles and hazards associated with electrical and photovoltaic power systems. The information in this guide is the best available at the time of publication and is believed to be technically accurate; it will be updated frequently. Application of this information and results obtained are the responsibility of the user
Recommended from our members
Photovoltaic Power Systems and the National Electrical Code: Suggested Practices
This suggested practices manual examines the requirements of the National Electrical Code (NEC) as they apply to photovoltaic (PV) power systems. The design requirements for the balance of systems components in a PV system are addressed, including conductor selection and sizing, overcurrent protection ratings and location, and disconnect ratings and location. PV array, battery, charge controller, and inverter sizing and selection are not covered, as these items are the responsibility of the system designer, and they in turn determine the items in this manual. Stand-alone, hybrid, and utility-interactive PV systems are all covered
ARC FLASH IN SINGLE-PHASE ELECTRICAL SYSTEMS
Arc flash and blast are hazards unique to electrical installations. Such events can start fires, destroy equipment, and severely injure or kill workers. NFPA 70E and IEEE 1584 are defining standards for arc flash hazard analysis used during system design, construction, and maintenance. Both focus on three-phase faults for calculations since three-phase power distribution is predominant in utility and industrial applications. However, discussion of arc flash in single-phase systems prevalent in residential and commercial facilities is excluded. Single-phase faults can also occur in a variety of industrial and utility circumstances.
This dissertation explores historic background and treatment of arc flash and foundation phenomena, considers IEEE results as published in the 1584-2018 standard, and documents the author\u27s work with single-phase arc flash.
Experiments were performed at the Schneider Electric facility, High Power Lab #3 in Cedar Rapids, Iowa in June and September 2020. This facility provided a test article; a full suite of voltage, current, and temperature instrumentation; high-speed video recording; and interface for a blast pressure transducer provided by the principal investigator. Test plan development used a template provided by Schneider. Scenarios were peer-reviewed in advance.
Experimental work revealed very low levels of heat released for most single-phase arc fault events at 434 volts and below though there was still blast, flash, and splatter of molten wire residue. In contrast, single-phase events at 460 volts and above produced sustained arcs, orders of magnitude more heat, and dangerously high levels of blast pressure.
Conclusions drawn are that low energy single-phase systems may be at low or very low risk of yielding arc flash burn-related injuries resulting from accidental short circuits. However, single-phase faults in systems with open circuit voltage at 460 volts or greater can produce significant levels of incident heat energy, flash, and blast pressure even at moderate levels of available fault current
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