scholarly journals IEEE 13-Node Incident Energy Analysis Using Online Platform

2021 ◽  
Author(s):  
MARINA CAMPONOGARA ◽  
ANA PAULA GHESTI MARCHESAN ◽  
DANIEL PINHEIRO BERNARDON ◽  
RAFAEL GRESSLER MILBRADT ◽  
TIAGO BANDEIRA MARCHESAN ◽  
...  
Keyword(s):  
Incident Energy ◽  
Energy Analysis ◽  
Energy Levels ◽  
Electric Arc ◽  
Protective Equipment ◽  
Boundary Values ◽  
Online Platform ◽  
Three Phase ◽  
Arc Flash ◽  
Flash Event

The thermal hazard is considered the most significant hazard from an arc flash event. The protection against this type of hazard is associated with the assessment of incident energy, a study that aims to analyze the possibility of occurrence of an electric arc, the incident energy produced by it and the necessary protections so that the work in electricity is safe. An incident energy analysis is performed to the 634 bus of IEEE 13 Node system using the ATP Draw software to simulate a three-phase shot-circuit and an online platform that runs the IEEE Std 1584-2018 model is employed to obtain the incident energy levels and arc-flash boundary values for different durations of arcing event. As a closing, the personal protective equipment required for the different time scenarios are analyzed, according to the two approaches proposed in NFPA 70E-2021.

An Electical Arc-Flash Hazard Analysis Primer: Reducing Arc-Flash Hazard Exposures Through Engineering Controls

2007 ◽  
Author(s):  
John J. Kolak
Keyword(s):  
Incident Energy ◽  
Hazard Analysis ◽  
Energy Levels ◽  
Electric Utility ◽  
Industrial Plant ◽  
Electrical Safety ◽  
Work Place ◽  
Engineering Controls ◽  
Severe Burns ◽  
Arc Flash

The problem of electrical workers being injured or killed by electrical arcs and blasts is one of the most significant safety issues in the industry today. Accident data reveals that over 2,000 people are severely burned annually by electrical arc blasts on the job (1) and many others receive less severe burns that still result in significant pain and suffering to the victim. The purpose of this presentation is to provide an overview of the arc-flash hazard analysis (AFHA) process and general guidance for those organizations wishing to integrate AFHA into their overall electrical safety program. The electric utility industry was the first non-academic group to study arc-flash hazards (AFH) when they noted that electrical workers often received the most severe burns from their clothing igniting and continuing to burn long after the initiating arc had extinguished. In particular, man-made fibers such as polyester, nylon, and rayon were known to melt and stick to the worker’s skin following an AF, and this resulted in burns many times worse than had the injured worker been wearing no clothing at all (2). Subsequent studies were performed by private organizations and they impacted both the engineering and safe work practices associated with industrial plant operations. The primary standards or studies included: • IEEE 1584 Guide for Performing Arc-Flash Hazard Calculations • NFPA 70E Standard for Electrical Safety in the Workplace • OSHA 29 CFR 1910.269: Electrical Power Generation, Transmission, and Distribution Standard Of these documents, the IEEE 1584 Guide was most influential to engineers because it provided formulas for calculating incident energy levels, arc-flash protection boundaries, and a host of other important variables necessary to evaluate AFH in the work place. The term ‘incident energy’ refers to the amount of heat concentrated per unit-area of the skin. Incident energy is measured in calories per square centimeter (cal/cm2) of skin surface area. For reference, a value of 1.2 cal/cm2 will result in a second-degree burn of human skin (3). The principal reason why AFHA is necessary is that studies revealed that electrical arcs are somewhat unpredictable events (4), and there were many cases where seemingly innocuous energy sources (small transformers) produced incident energy levels that far exceeded the limitations of flame resistant (FR) clothing or other forms of personal protective equipment. It became obvious that the best method for protecting employees from AFH would be to evaluate the hazard level and then mitigate it through the use of engineering controls. Paper published with permission.

Arc-Flash Incident Energy Analysis: Renewal Recommendations

2021 ◽  
pp. 2-12
Author(s):  
Paul B. Sullivan ◽  
Daniel Doan ◽  
Ken Jones
Keyword(s):  
Incident Energy ◽  
Energy Analysis ◽  
Arc Flash

Technical textiles for protection against Arc-flash fire: Savesplash®

2020 ◽  
pp. 67-78
Author(s):  
Nandan Kumar ◽  
Sainath Shrikant Pawaskar
Keyword(s):  
Attenuation Factor ◽  
Threshold Energy ◽  
Single Layer ◽  
Weather Conditions ◽  
Electric Arc ◽  
Risk Category ◽  
Technical Textiles ◽  
Flash Fire ◽  
Level 3 ◽  
Arc Flash

Flash fire caused by electric arc is different than that caused by flammable liquids/fumes or combustible dusts. A suitable protective clothing for protection against electric arc-flash must be designed as per Indian weather conditions. Currently available garments are manufactured using two or three layers of woven/nonwoven combinations to achieve higher Hazard Risk Category (HRC) rating (level 3 and above). However, they are heavy and not comfortable to the end users. Savesplash® is a single layer inherent flame-retardant knitted fabric. Its arc rating was determined using ASTM standards. It achieved arc thermal performance value (ATPV) of 41 cal/cm2, breakopen threshold energy (E_BT) of 42 cal/cm2 and heat attenuation factor (HAF) of 94% when tested as per ASTM F1959/F1959M-14 which translated into an arc rating of 41 cal/cm2. This is equivalent to HRC level 4 ratings as per National Fire Protection Association’s NFPA 70E standard (USA). Further, cut and sewn gloves (HM-100) developed using Savesplash® fabric reinforced with leather on palm area achieved ATPV of 63 cal/cm2 and HAF of 94.5% when tested as per ASTM F2675/F2675M-13.

Electromagnetic analysis of an AC electric arc furnace including the modeling of an AC arc

2010 ◽  
Vol 29 (3) ◽  
pp. 667-685 ◽  
Author(s):  
Arash Kiyoumarsi ◽  
Abolfazl Nazari ◽  
Mohammad Ataei ◽  
Hamid Khademhosseini Beheshti ◽  
Rahmat‐Allah Hooshmand
Keyword(s):  
Electromagnetic Field ◽  
Electric Arc ◽  
Electromagnetic Analysis ◽  
Arc Furnace ◽  
Molten Bath ◽  
3D Fem ◽  
Content Type ◽  
Three Phase ◽  
Ac Arc ◽  
Different Parts

PurposeThe purpose of this paper is to present a 3D finite element model of the electromagnetic fields in an AC three‐phase electric arc furnace (EAF). The model includes the electrodes, arcs, and molten bath.Design/methodology/approachThe electromagnetic field in terms of time in AC arc is also modeled, utilizing a 3D finite element method (3D FEM). The arc is supposed to be an electro‐thermal unit with electrical power as input and thermal power as output. The average Joule power, calculated during the transient electromagnetic analysis of the AC arc furnace, can be used as a thermal source for the thermal analysis of the inner part of furnace. Then, by attention to different mechanisms of heat transfer in the furnace (convection and radiation from arc to bath, radiation from arc to the inner part of furnace and radiation from the bath to the sidewall and roof panel of the furnace), the temperature distribution in different parts of the furnace is calculated. The thermal model consists of the roof and sidewall panels, electrodes, bath, refractory, and arc. The thermal problem is solved in the steady state for the furnace without slag and with different depths of slag.FindingsCurrent density, voltage and magnetic field intensity in the arcs, molten bath and electrodes are predicted as a result of applying the three‐phase AC voltages to the EAF. The temperature distribution in different parts of the furnace is also evaluated as a result of the electromagnetic field analysis.Research limitations/implicationsThis paper considers an ideal condition for the AC arc. Non‐linearity of the arc during the melting, which leads to power quality disturbances, is not considered. In most prior researches on the electrical arc furnace, a non‐linear circuit model is usually used for calculation of power quality phenomena distributions. In this paper, the FEM is used instead of non‐linear circuits, and calculated voltage and current densities in the linear arc model. The FEM results directly depend on the physical properties considered for the arc.Originality/valueSteady‐state arc shapes, based on the Bowman model, are used to calculate and evaluate the geometry of the arc in a real and practical three‐phase AC arc furnace. A new approach to modeling AC arcs is developed, assuming that the instantaneous geometry of the AC arc at any time is constant and is similar to the geometry of a DC arc with the root mean square value of the current waveform of the AC arc. A time‐stepping 3D FEM is utilized to calculate the electromagnetic field in the AC arc as a function of time.

scholarly journals Nuclear excitation and disintegration collisions involving strong Interaction─I

1937 ◽  
Vol 162 (911) ◽  
pp. 529-556 ◽  
Keyword(s):  
Strong Interaction ◽  
Incident Energy ◽  
High Probability ◽  
Collision Cross Section ◽  
Energy Levels ◽  
Stable Complex ◽  
Nuclear Excitation ◽  
Resonance Effects ◽  
Resonance Phenomena ◽  
Probability Of Capture

The study of collisions between nuclear particles has developed to a remarkable extent with the discovery of the neutron and the introduction of artificial methods for effecting nuclear disintegration. It has been found in the last few years that the interpretation of the observed results is by no means as simple as was first expected. This situation is most apparent when the explanation of the variation of probability of capture of slow neutrons by different nuclei is considered. This probability varies in a very irregular manner from element to element and pronounced selective effects occur in certain cases. Attempts to explain (Elsasser and Perrin 1935; Bethe 1935) these resonance phenomena in terms of the usual approximations of quantum collision theory were soon found to be inadequate, All such attempts were based on the assumption that the Chance of a nuclear collision being elastic is high compared with that of its resulting in capture or excitation. A high probability of capture (with emission of radiation) or excitation could then only appear together with a high probability of elastic collision and this is frequently contradicted by the experimental results. The sharpness of the observed resonance phenomena was also difficult to under­stand on this basis. It was first pointed out by Bohr (1936) that the initial assumptions concerning the probability of elastic collisions, virtually involving the treatment of the elastic scattering as a one-body problem in the first approximation, cannot be valid for nuclei in which the particles, even is existing separately in the nuclei at all, are so closely packed. On making a close collision with a nucleus a particle, such as an α -particle, neutron or proton, comes into close and strong interaction with a number of nuclear particles and its incident energy becomes distributed among them. It is only when a particular particle receives sufficient energy to leave the quasi-stable complex formed that a disintegration particle is emitted. (This may of course be the original incident particle, in which case the collision would be an elastic or excitation one.) Otherwise the surplus energy is emitted as radiation. The resonance phenomena arise from the energy levels of the quasi-stable complex. If the incident energy is such that the total energy is equal or nearly equal to that of one of these energy levels, the range of interaction and hence the collision cross-section is quite large. This point of view must be adopted not only when dealing with neutron collisions but in all cases in which the impinging particle does not possess an energy greatly in excess of the minimum necessary for the process to occur. Disintegrations produced by charged particles, in which resonance effects have been observed for some time (Feather 1937, P. 154), must therefore be capable of description in this way.

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