One of the most important protective devices in power systems are fuses which have been used for ages. Passing short circuit current from fuse causes to warm fuse element that it will open this path. Fuse temperature can directly affect fuse operation and its melting as well. Therefore, fuse should be designed in a way that it does not operate at nominal current and instantaneous over currents whereas it should operate at error case. In this paper, firstly, fuse element is investigated and its behavior is studied. Then, a sample fuse with its different sections is simulated under sinusoidal and non- sinusoidal currents. After that, different parameters such as thermal distribution, thermal flux, and electrical potential in all fuse parts are obtained for sinusoidal and non-sinusoidal currents. Also, Fuse temperature for various THD values is determined. Finally, an equation to determine fuse nominal current due to harmonics is presented.
Keywords
Thermal Flux, Current Harmonics, Power System Fuses, Finite Element Analysis, ANSYS
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