• Journal of the Korean Society of Safety
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• v.38 no.4
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• pp.8-14
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• 2023

This study presents the characteristics of short circuits (SCs) caused by excessive currents in high-voltage cables used in electric vehicles and emphasizes the need to calculate the cross-sectional areas of these cables according to the SC current. Three direct current power supplies were connected in parallel to test the SC characteristics caused by excessive currents, and a timer and a magnetic contactor were used to deliver the conduction time and SC current. A circular infrared-radiation heater was used to test the temperature-dependent SC characteristics, a thermocouple was used to measure the temperature, and a shunt resistor was used to measure the current. As the SC current increased, the fusing time of the cable decreased. Additionally, a high-voltage cable (with an area of 16 mm² ) used in electric vehicles fused when a current (approximately equal to 55 times the allowable current) flowed for 0.2 s (operating time of the protective device). When the SC current is 10 kA, the cable may fuse during the operating time of the protective device, thus creating a fire hazard. In electric vehicles, the size of the SC current increases in proportion to the capacity of the battery. Thus, the cross-sectional areas of the cables used should be calculated accordingly, and cable operations should be properly coordinated with the surrounding protective devices.