• Proceedings of the Korea Institute of Fire Science and Engineering Conference
• /
• 2008.04a
• /
• pp.269-272
• /
• 2008

This paper deals with damage patterns of cabinet panel for low voltage deteriorated by flame. In order to analyze damage patterns, we used Metallurgical Microscope, x-ray system, and Fourier Transform Infrared spectroscopy. Firstly, Metallurgical microscope was used for analysis of electrical causes, such as electric short and overload. Secondly, X-ray system was used for analysis of internal characteristics of circuit breakers. Lastly, Fourier Transform Infrared spectroscopy was used for analysis of damage direction by flame. The following results were obtained.

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

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.628-632
• /
• 2002

Low voltage circuit breakers which interrupt rapidly and raise the reliability of power supply are widly used in power distribution systems. In the paper, it was investigated how much Interrupting capability was improved by correcting the shape of the contact system in molded case circuit breaker(below MCCB), especially arc runner. Prior to the interrupting testing, it was necessary for the optimum design to analyze electromagnetic forces on the contact system, generated by current and flux density. This paper presents both our compuational analysis and test results on contact system in MCCB

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1751-1753
• /
• 2002

Arc phenomena occur in the air, must be more diverse than vacuum and SF6. An air arc interruption method has been used in low rated voltage circuit breakers such as ACB, MCCB and MCB. Most of them have the arc chamber composed of arc chutes and lateral walls that made of many kinds of materials. Therefore, the criterion of material selection is necessary for breaking capacity improvement. So, we selected some contact and lateral wall materials, and carried out short circuit tests. Especially, some parameters of arc plasma properties were very different each polymeric wall material.

• Proceedings of the KIEE Conference
• /
• 2002.11d
• /
• pp.154-156
• /
• 2002

본 논문은 저압 차단기에 적용되는 IEC 60947-2 (Circuit breakers)와 전류고조파(Current harmonic) 내성시험 규격인 IEC 61000-3-2. IEC 61000-3-4에 대한 규격의 적용범위, 시험범위, 고조파에 대한 개념, 차단기의 고조파에 대한 영향 및 시험설비의 요구조건을 고찰하고, 16A 초과 전류 고조파 시험적용 방법과 시험결과를 고찰하고자 한다.

• Journal of Korean Institute of Fire Investigation
• /
• v.11 no.1
• /
• pp.37-40
• /
• 2008

This paper deals with damage patterns of cabinet panel for low voltage deteriorated by flame. In order to analyze damage patterns, we used Metallurgical Microscope, x-ray system, and Fourier Transform Infrared spectroscopy. Firstly, Metallurgical microscope was used for analysis of electrical causes, such as electric short and overload Secondly, X-ray system was used for analysis of internal characteristics of circuit breakers. Lastly, Fourier Transform Infrared spectroscopy was used for analysis of damage direction by flame.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.980-981
• /
• 2008

Mechanical spring and hydraulic pressure operated mechanisms are applied in most of today's High Voltage Gas Insulated Switchgear(GIS)s. This paper proposes a new type of operation mechanism for GIS circuit breakers rated at 245kV and 40kA. The Motor-Direct-Drive-Mechanism (MDDM) has many advantages compared to conventional operating mechanisms. It has a very simple structure with only one moving part, low mechanical stress and audible noise. It also allows monitoring, operation speed control and self-diagnosis functions.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.114-116
• /
• 2007

Mechanical spring and hydraulic pressure operated mechanisms are applied in most of today's High Voltage Gas Insulated Switchgear(GIS)s. This paper proposes a new type of operation mechanism for GIS circuit breakers rated at 245kV and 40kA. The Motor-Direct-Drive-Mechanism (MDDM) has many advantages compared to conventional operating mechanisms. It has a very simple structure with only one moving part, low mechanical stress and audible noise. It also allows monitoring, operation speed control and self-diagnosis functions.

• Proceedings of the KIEE Conference
• /
• 2006.07c
• /
• pp.1540-1541
• /
• 2006

For limitation and interruption of short circuit currents from low voltage to extra high voltage applications, the electrical equipment including fuses and circuit breakers, are widely used today. But in order to anticipate increasing needs for effective and competitive device for limiting the growing fault current in electrical power systems, fault current limitation technologies and fault current limitation devices are widely introduced and investigated in these days. Fault current limiters are emerging electric equipment which is under development using various methods including superconducting fault current limiter, solid state fault current limiter, arc driving fault current limiters. And these various methods have some advantages and disadvantages to take into considerations In order to commercialize fault current limiters in the electrical networks, a lot of discussions should be given on the point that fault current limiting methods, need for fault current limiters, coordination with existing protective system, and field experience before commercialization. In this paper, recent trends of fault current limiting technologies will be reviewed and the key issues of superconducting fault current limiters will be dealt with. And finally, future applications of superconducting fault current limiters would be discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.6
• /
• pp.137-144
• /
• 2002

Low voltage circuit breakers which interrupt rapidly and raise the reliability of power supply are widely used in power distribution systems. In the paper, it has been investigated how much interrupting capability is improved by correcting the shape of the contact system in molded case circuit breaker(below MCCB), especially arc runner. Prior to the interrupting testing, it is necessary for the optimum design to analyze electromagnetic forces on the contact system generated by current and flux density. This paper presents both our computational analysis and test results on contact system in MCCB.