Although arc flash has been a concern amongst the electrical industry for many years, it is only relatively recently that standards by the IEEE have been established on calculating the amount of energy behind an arc flash event. However, these standards only apply to AC systems, where extensive testing and research have been performed. Although the NFPA has provided recommendations on how to calculate the incident energy for DC arc flash events, these have not become the defining standard like those seen for AC. One equation outlined in the NFPA70E, the Maximum Power Method, does provide engineers with a formula to calculate DC arc flash incident energy but as the NFPA states this can be quite conservative. However, the NFPA70E also mentions a Detailed Arcing Current and Energy Calculations Method which contains formulas proposed by various researchers who conducted their own DC arc flash testing but there is scarce info on how these methods compare to the Maximum Power Method. This paper will investigate the relative power of two of the formulas proposed in the alternate method, the results from Stokes/Oppenlander and the results from Paukert, over a variety of parameters that affect DC arcing power. These will then be compared to relative power of the Maximum Power Method, as well as the relative power of the AC equations formed from measurements. Although the results in this paper are not aiming to be a defining standard, the aim is to provide engineers with information on when one methodology is more suitable to use for a given set of certain parameters.

Arc flash is one of the two primary hazards encountered by workers near electrical equipment. Most applications where arc flash may be encountered are alternating current (AC) electrical systems. However, direct current (DC) electrical systems are becoming increasingly prevalent with industries implementing more renewable energy sources and energy storage devices. Little research has been performed with respect to arc flash hazards posed by DC electrical systems, particularly energy storage devices. Furthermore, current standards for performing arc flash calculations do not provide sufficient guidance when working in DC applications. IEEE 1584-2002 does not provide recommendations for DC electrical systems. NFPA 70E provides recommendations based on conservative theoretical models, which may result in excessive personal protective equipment (PPE). Arc flash calculations seek to quantify incident energy, which quantifies the amount of thermal energy that a worker may be exposed to at some working distance. This thesis assesses arc flash hazards within a substation backup battery system. In addition, empirical data collected via a series of tests utilizing retired station batteries is presented. Lastly, a predictive model for determining incident energy is proposed, based on collected data.

Arc Flash events occur due to faults in electrical equipment combined with a significant release of energy across an electrical arc. Due to the large energy release, plasma is generated, pressures increase, and the plasma expands. Under these conditions the plasma becomes excited enough to liquefy metal causing physical damage to equipment and any humans in the vicinity. This thesis investigates the state of art for detection of arc flash events and investigates a method of improving detection reliability, and speed by monitoring the high frequency voltage / current patterns utilizing methods similar to arc flash circuit interrupters (AFCI). A second alternative detection approach is determined through analysis of the physics of plasma development. The current state of art is based upon light detection. However this thesis experimentally investigates what happens before the arc event emits visible light. The results show that current flows to ground during an arc event slightly prior to the production of light. Further it shows through analysis of the physics of plasma that a high speed plasma detector has the potential to identify an arc event before the presence of visible light. Through the design and construction of experimental test setups, and physics analysis, this thesis provides new paths for detecting arc events that present opportunities to improve detection time.

O trabalho tem como objetivo avaliar e propor a utilização de soluções tecnológicas que permitam a redução dos riscos causados por arcos elétricos nas instalações de uma unidade industrial com sistema isolado de geração elétrica. Por ser extremamente danosa à segurança das pessoas que interagem com uma instalação elétrica e por causar danos significativos aos equipamentos e instalações, a energia incidente, proveniente de um arco elétrico, deve ser mensurada em conformidade com as normas existentes e os riscos devem ser controlados e mitigados, de maneira a não comprometer a integridade física das pessoas e das instalações. Dessa forma, o presente trabalho propõe alterações no sistema de proteção e a inserção de dispositivos dedicados à identificação de arcos elétricos no interior de painéis da unidade em questão, contribuindo significativamente para a redução da energia incidente liberada na ocorrência de um arco elétrico. Essa redução da energia incidente é conseguida devido à redução do tempo para eliminação da falta, necessitando, dessa forma, de dispositivos e relés de proteção voltados exclusivamente para a proteção contra arco elétrico. / This dissertation aims to evaluate and propose the use of technological solutions that enable the reduction of risks caused by arc flash on the premises of an industrial unit with insulated system of electricity generation. It may be extremely damaging to the safety of people who interact with electrical installations and could cause significant damage to the equipment and facilities, the incident energy from an arc flash should be measured in accordance with existing standards, their risks must be controlled and attenuated, in order not to compromise the physical integrity of people and facilities. That way, this paper proposes changes into the system of protection and the insertion of devices dedicated to the identification of arc flashes inside panels of the unit concerned, contributing significantly to the reduction of incident energy released in the event of an arc flash. This reduction is obtained by lowering the time for the elimination of absence, requiring, therefore, devices and protective relays devoted exclusively to protect against electric arc.

O trabalho tem como objetivo avaliar e propor a utilização de soluções tecnológicas que permitam a redução dos riscos causados por arcos elétricos nas instalações de uma unidade industrial com sistema isolado de geração elétrica. Por ser extremamente danosa à segurança das pessoas que interagem com uma instalação elétrica e por causar danos significativos aos equipamentos e instalações, a energia incidente, proveniente de um arco elétrico, deve ser mensurada em conformidade com as normas existentes e os riscos devem ser controlados e mitigados, de maneira a não comprometer a integridade física das pessoas e das instalações. Dessa forma, o presente trabalho propõe alterações no sistema de proteção e a inserção de dispositivos dedicados à identificação de arcos elétricos no interior de painéis da unidade em questão, contribuindo significativamente para a redução da energia incidente liberada na ocorrência de um arco elétrico. Essa redução da energia incidente é conseguida devido à redução do tempo para eliminação da falta, necessitando, dessa forma, de dispositivos e relés de proteção voltados exclusivamente para a proteção contra arco elétrico. / This dissertation aims to evaluate and propose the use of technological solutions that enable the reduction of risks caused by arc flash on the premises of an industrial unit with insulated system of electricity generation. It may be extremely damaging to the safety of people who interact with electrical installations and could cause significant damage to the equipment and facilities, the incident energy from an arc flash should be measured in accordance with existing standards, their risks must be controlled and attenuated, in order not to compromise the physical integrity of people and facilities. That way, this paper proposes changes into the system of protection and the insertion of devices dedicated to the identification of arc flashes inside panels of the unit concerned, contributing significantly to the reduction of incident energy released in the event of an arc flash. This reduction is obtained by lowering the time for the elimination of absence, requiring, therefore, devices and protective relays devoted exclusively to protect against electric arc.