• Proceedings of the KIPE Conference
• /
• 2013.07a
• /
• pp.153-154
• /
• 2013

고전압, 대전류를 갖는 뇌서지는 전원회로에 유입되었을 때 소자 파손 및 회로 오동작 등의 문제를 일으킨다. 이에 대한 보호대책으로 SPD(Surge Protection Device)소자와 스파크-갭(Spark-gap)을 주로 사용한다. 이 때, 기존의 스파크-갭은 뇌서지 유입 시 방전현상 이후에 발생된 스파크-갭의 패턴 마모로 패턴의 복구가 불가능하고, 불규칙하고 변칙적인 방전으로 인하여 발생되는 서지주요 예측경로의 소자 및 패턴 파괴와 같이 2차적인 문제를 발생시킨다. 이를 해결하기 위해 본 논문에서는 초기 유입 시부터 스파크-갭의 방전을 통해 에너지를 우회시킴으로서 전원회로의 뇌서지 부담을 줄여 전원회로의 안전성 및 안정적인 정상동작을 확보하는 대책을 제안하고, 스파크-갭의 구조에 따른 효과를 실험을 통해 검증한다.

• Proceedings of the KIEE Conference
• /
• 2000.07d
• /
• pp.3094-3096
• /
• 2000

In the distribution systems, there are generally two sources of transient over-voltages. One is the capacitor switching surge and the other is the lightning surge. This paper is written about the measuring and analysis of switching over-voltages in the 22.9 kV multi-grounded distribution systems. The measurement was performed in the Kochang distribution test line in January, 2000.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.11
• /
• pp.1949-1955
• /
• 2010

This paper describes the characteristic and effectiveness of combined GIL transmission line through lightning surge analysis. In addition the XLPE cable is analyzed in the same condition to compare with GIL. Lighting surge analysis is carried out by EMTP/ATP-Draw to obtain overvoltage of GIL and XLPE cable at service-point and load-out area of underground line. Propagation velocity is calculated in combined transmission lines with GIL and XLPE cable. The overvoltage is also analyzed on GIL and XLPE cable with or without arrester operation. The Analysis results show that overvoltage of GIL is occurred higher than XLPE cable at the same condition. Therefore it is evaluated that the application of GIL at the field should be considered cautiously when more detailed transient analysis, another electrical testes and economic evaluations are implemented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 1999.11a
• /
• pp.490-493
• /
• 1999

Due to the miniaturization of electrical components and assembles on signal and telecommunication circuits, transient overvoltages caused by switching operation or lightning surge has become more interesting concern to the field of electrical engineering. This paper describes the development of transient voltage blocking devices (TBDs) that can protect sensitive signal and telecommunication devices from overvoltages. Two kinds of TBDs are designed and tested by using a combination surge generator which can produce the standard impulse current of 8/20${\mu}$s 2.1kA according to the IEC 1000-4-5 standard. From the simulation and experimental reults, it is confirmed that the proposed TBD has an enough protection performance in low insertion loss and tight clamping voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05c
• /
• pp.208-212
• /
• 2003

Silicon transient voltage suppressors (TVSs) are clamping devices that limit voltage spikes by low impedance avalanche breakdown of a rugged silicon PN junction. They are used to protect sensitive components from electrical overstress such as that caused by induces lightning, inductive load switching and electrostatic discharge. In this paper, we present static and dynamic characteristics of TVS diode using thermal analysis simulation software. And also, it is presented that the thermal dissipation characteristics of TVS diode in the transient state.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2229-2231
• /
• 2005

Recently, damages of electronic equipments due to lightning surges coming from AC power lines are increasing. In this work, to propose the effective installation methods of surge protective devices(SPDs), the protective performances of SPDs in actual-sized test circuits were experimentally investigated. In order to obtain the lowest limiting voltage and best protection, long leads of SPDs in installation practices are significantly undesirable. An effective installation method of SPDs for AC mains was proposed. The way of installing SPDs at every branch circuits is more effective than that of installing a SPD near the point of entry.

• Proceedings of the KIEE Conference
• /
• 2003.07c
• /
• pp.1791-1793
• /
• 2003

In order to analyze the dynamic characteristics of ground impedance in large grounding system for lightning and surge protections, a novel method for measuring the ground impedance as a function of frequency was proposed. The experiments were carried out in the grounding system composed of ground rods and mesh grids. The test current was injected by the variable frequency inverter whose frequency is linearly controlled in the range of $5{\sim}500$kHz. The ground impedance and frequency response of the grounding system were mainly caused by the inductive current flowing through grounding conductors over the frequency of 2002. In the combined grounding system of rods and mesh grids, inductive component of ground impedance was significantly decreased. It was fumed out that the grounding system is effective for the surge protection.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2006.05a
• /
• pp.338-341
• /
• 2006

This paper presents the leakage current characteristics of ZnO varistors exposed to the $8/20{\mu}s$ lightning impulse currents as functions of the number of injection and amplitude of impulse currents. The surge simulator system ECAT that can generate $8/20{\mu}s$ impulse currents with a peak short-circuit of $5[kA_p]$ was used. Leakage currents flowing through ZnO varistors subjected to the $8/20{\mu}s$ impulse currents were measured under 60 Hz AC voltages. The trend curves of resistive leakage current of ZnO varistors were analytically calculated.

• Proceedings of the KIPE Conference
• /
• 2012.07a
• /
• pp.385-386
• /
• 2012

기존 뇌서지에 관한 논문은 정보통신 설비 및 전력계통의 대책에 관한 연구가 진행되어 왔으나, SMPS에 관한 연구는 부진하였다. 따라서, 본 논문에서는 조합파 신호발생기를 통하여 서지전압 인가에 따른 플라이백 컨버터에서의 서지전류 경로를 분석한다. 또한, 새로이 발견한 서지전류로 인하여 발생되는 주요 소자파손 원리를 제시한다. 최종적으로 서지경로 상의 실제 측정 결과를 제시하여 제안 방식의 타당성 및 유효성을 검증하였다.

• Proceedings of the KIEE Conference
• /
• 2002.11a
• /
• pp.194-196
• /
• 2002

This paper deals with a proper installation methods of SPDs for information-oriented and computerized equipments. Since the information and computerized equipments have AC power lines and communication lines, the potential difference by lightning surge occurs between grounding points of the AC power lines and subscriber protectors, and it causes the flashover and damage. So, we have investigated the effect of the installation methods of surge protectors on the control of overvoltages, using a real-sized test circuit with a customer's facility. As a consequence, it was confirmed that the protection methods by installation of SPDs on the neighbor branch circuit was effective.