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This paper presents a method to simulate the current and voltage of an electric arc initiated at the contact's opening in a contactor. Based on a simplified model of the electric arc and also on the dynamics of the contacts during the opening, this method allows to simulate the arc ignition as well as the arc extinction. This study is based on the hypothesis that the arc dynamic is much faster than...
With the rising demand for electrical energy in an aircraft and the increase in operating voltages of the electrical distribution networks, the probability of occurrence of an arc fault is also increased. New protection devices such as arc fault detectors are now integrated in the network to break the circuit in case of an arcing event. To determine the optimum location of these protection devices,...
In this article, we present a repeatable and calibrated arc generator and the method we developed to initiate an arc. The test bench we propose can generate AC and DC currents and series and parallel arc faults on variable loads. Using a step up transformer, arc initiation is obtained by producing an overvoltage: the arc is then sustained using an AC or DC line generator. Atmospheric conditions (temperature,...
Arc faults can be accidentally produced in any electrical system. In order to test arc detection systems (AFCB), but also to design electrical systems, it is possible to simulate arcs faults starting from models. To analyse and detect these arc faults, accurate models are needed. In this paper a new approach to the arc modelling is discussed. In the first part of the paper we compare the different...
Environmental monitoring systems are more pervasive as sensors become smaller, less expensive, and more power-efficient. The ever-increasing volume and variety of realtime data poses significant technical challenges with respect to sensor/system configuration, data quality management, data mining, and data dissemination. The latest version of the Land/Ocean Biochemical Observatory visualization (LOBOviz)...
This article describes the design and use of a repeatable and calibrated arc fault generator. We have developed a test bench which can generate AC and DC currents and series and parallel arc faults on variable loads and have chosen a method which consists in producing an overvoltage in arc initiation, obtained with a step-up transformer; a line generator (AC or DC) then sustains the arc. We show the...
Sustaining measurements of water quality parameters in sensitive watershed habitats is challenging, particularly during critical periods such as spring blooms, and major run off events. Direct, in situ measurements of nitrate have been difficult to obtain until the development of the ISUS (In Situ Ultraviolet Spectrometer, Johnson & Coletti 2002) and more recently the next generation SUNA (Submersible...
The Land/Ocean Biogeochemical Observatory (LOBO) system was initially developed by MBARI under the NSF Biocomplexity program to monitor the land/ocean interface for coastal zone management. The system utilizes highly robust and accurate sensors to provide sustained monitoring of critical watershed habitats in challenging environmental conditions in real time. With the incorporation of novel anti-fouling...
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