• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.3
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• pp.175-179
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• 2022

Magnetic arc extinguishing technology is effective as an extinguishing device for low-voltage direct current (DC) circuit breakers with a resistive load of ≤4 kW. The separation distance between the magnet and the electrical contact must be shortened to increase the magnetic arc extinguishing force. However, if the magnet is installed too close to the electrical contact points, the magnet is exposed to high temperatures due to the arc current generated when the load current is cut off and the magnetism is lost. To solve this problem, the effective magnetic flux density at the electrical contact can be maintained high by placing the arc extinguishing magnet in a tandem structure with the electrical contact point between them, and the proper separation distance between the contact points and the magnet can be maintained. In addition, an electric arc extinguishing technology that emits arc energy using a series circuit of diode and resistor is used to suppress the continuous arc voltage generated by the inductive load. For the proposed circuit breaker, the breaking characteristics are analyzed through the breaking test for the DC load of the 760 V level, the load power of 4 kW, and the time constant of 5 ms, and an appropriate arc extinguishing design guideline is proposed.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.1
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• pp.21-26
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• 2012

In recent years, DC distribution systems are becoming hot issue due to the increase in digital loads and DC generation systems according to the expansion of renewable energy technologies. However, removing the fault current in DC grids is comparably difficult since the current in DC grids has no zero-crossing point like in AC grids. Thus, developing dedicated DC circuit breakers for DC grids is necessary to get safety for people and electrical facilities. This paper proposes magnet arc extinguishing method to develop a 300[$V_{DC}$]/10[A] DC circuit breaker. The performance of the proposed DC circuit breaker was verified by an experimental circuit breaker test system built in this research.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.6
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• pp.495-499
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• 2012

Recently, DC distribution systems become hot issues since DC type loads increase rapidly according to the expansion of IT equipment such as computers, servers, and digital devices; DC type loads will cover 50% for all electricity loads in 2020 which was mere 10% in 2000. DC distribution systems are also accelerated by the expansion of renewable power systems since they are easy to be interfaced with DC grids rather than AC grids. However, removing the fault current in DC grids is comparably difficult since the current in DC grids has non zero-crossing point like in AC grids. Thus, developing dedicated DC circuit breakers for DC grids is necessary to get safety for human and electrical facilities. Magnet arc extinguishing method is proper to small size DC circuit breakers. However, simple Magnet arc extinguishing method is not enough to break inductive fault currents. This paper proposed a novel DC circuit breaker against inductive fault current defined by IEEE C37.14-2004 Standard for Low-Voltage DC Power Circuit Breakers Used in Enclosures. The performance of the proposed DC circuit breaker was verified by an experimental circuit breaker test system built in this research.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.263-264
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• 2011

최근 들어 디지털 제품의 급증으로 인해 직류를 사용하는 부하가 증가하고, 직류 배전망에 대한 관심이 높아 지고 있다. 하지만 직류는 교류와 다르게 직류 배전시 부하의 단락 사고가 발생하면 지속적으로 아크전압이 발생하는 문제가 있기 때문에 차단이 어렵다. 인체의 안전과 전력설비 및 기기의 안전성을 확보하기 위해서는 고장전류로부터 계통을 보호하기 위한 차단기술이 필요하다. 본 논문에서는 효과 적인 직류 차단에 대하여 실험적으로 연구하였다.