• Transactions on Electrical and Electronic Materials
• /
• v.17 no.5
• /
• pp.289-292
• /
• 2016

This paper dealt with the optimal design of a follow current disconnector for DC arresters used in electric traction vehicles. The disconnector separates the ground lead from an arrester to prevent a line-to-ground fault of an aged arrester and should not affect the operation and function such as the reference and the clamping voltage of the connected arrester. The designed disconnector is composed of a resistor, a spark gap, and a cartridge. The results showed that the sparkover voltage increased with the gap distance whereas the reference voltage was almost the same as that without the disconnector. The sparkover voltage was 3.95 kV when the gap distance was 0.5 mm. Regardless of the gap distance, the reference and the clamping voltage of the assembled disconnector with an arrester were measured to be the same as those of the arrester alone.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.546-547
• /
• 2005

This study aims to evaluate the properties and the performance of the newly designed disconnector for surge arrester. This disconnector was verified with the performance in long-duration current impulse test and high current impulse test. And time-current characteristic test was done at 20A, 200A and 800A(3points) for simulating the internal fault condition of the arrester. The results of this test was very good. Consequently, the newly designed disconnector was, evaluated that it is possible to be used for surge arrester in distribution line system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.541-542
• /
• 2007

The paper also introduces a new Distribution Class ground lead disconnector design that not only extends the claimable detonation range well below the 20 amps specified in industry standards, but is very durable when exposed to severe arrester durability tests. Finally. this paper shows how this next generation disconnector interacts with the connected arrester to improve the overvoltage withstand capability of the arrester assembly. The interaction of the disconnector grading capacitor with the series-connected arrester metal oxide disc elements actually improves the arrester assembly temporary overvoltage withstand capability, making the design less vulnerable to TOV failures. Since the vast majority of distribution class arresters are sold domestically with ground lead disconnectors, this design improvement in the disconnector to improve detonation reliability also translates into a significantly improved distribution class arrester design.

• Proceedings of the KIEE Conference
• /
• 2007.07a
• /
• pp.1980-1981
• /
• 2007

This paper introduces performance characteristics of existing distribution class arrester ground lead disconnecting devices. The paper also introduces a new distribution class ground lead disconnector design that not only extends the claimable detonation range well below the 20 amps specified in industry standards, but is very durable when exposed to severe arrester durability tests. Finally, this paper shows how this next generation disconnector interacts with the connected arrester to improve the overvoltage withstand capability of the arrester assembly.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.2118-2119
• /
• 2008

The paper introduces a new Distribution Class ground lead disconnector design that not only extends the claimable detonation range well below the 20 amps specified in industry standards, but is very durable when exposed to severe arrester durability tests. Finally, this paper shows how this next generation disconnector interacts with the connected arrester to improve the overvoltage withstand capability of the arrester assembly.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.687-690
• /
• 2000

This paper provides the result of the analysis of the lightening arresters which were disconnected from the power line due to the overvoltage having high current. The effect of thermal runaway on the microstructures of lightening arrester's block was intensively investigated. The chance of the microstructures of the blocks was limited only on the breakdown paths and near them. Also even though a disconnector was disconnected from the arrester, some of the lightening arrester were showed normal characteristics.

• Proceedings of the KIEE Conference
• /
• 1996.07c
• /
• pp.1807-1809
• /
• 1996

The axial discharge at switching operations of EHV $SF_6$ disconnector can lead to the breakdown to the enclosure. Precursor in periphery zone leads to formation of leader over some time delay. Injected charge value depends on electric field and gap geometry. The calculation method for parameters of $SF_6$ insulation for DS in EHV-GIS is suggested by using the new criterion of leader inception in connection with periphery field nearby the boundary of streamer zone.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.40 no.6
• /
• pp.630-637
• /
• 1991

For the measurement of time-varying electric fields and related quantities, a field sensor should be sensitive to the field to be measured, and also designed having an accurate transfer function. In this paper, a theoretical model which adequately describes the operation principle and design of the sensor is presented. A calibration and/or correction technique of the sensor is also studied which enables a precise determination of the response of the sensor to an electric field. As a result, the developed electric field sensor and measuring system are known to be accurate within a bandwidth from a few Hz to 200 MHz. It is found that the sensor can be used directly in the measurement of very fast transient voltages and time-varying electric fields occurring during disconnector operations in a gas-insulated substation. It may be useful also for the study on the electromagnetic environmental parameters.

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.318-321
• /
• 1991

For measuring the transient electromagnetic fields and related quantities created by disconnector operations in GIS, one needs the wide bandwidth sensors with simple transfer functions. This paper describes a new developed electric field sensor to measure the very fast transient electric fields and voltages, and the measuring principle, design and construction of planar electric field sensor are described. A calibration and/or correction technique of the sensor is investigated which enables an accurate determination of the sensor response to the time-changing electric fields. As a consequence, the low voltage calibrations certify that a rise time of 1.7 [ns] is achieved for the planar electric field sensor and a total bandwidth extending from several Hz to 200 MHz for the measuring system which presents the constant division ratio as a function of frequency.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.45-46
• /
• 2011

단로기와 회로 차단기의 스위칭 동작에 의해 발생하는 Very Fast Transient Overvoltage(VFTO)는 변압기, 회로차단기 등 GIS 전력소자에 큰 충격을 주어 잠재적인 위험이 된다. VFTO는 전력기기 소자 및 절연체 손상의 주된 원인이므로 시스템을 설계할 때 반드시 VFTO 최대값을 고려해야 한다. 본 논문에서는 55kV Gas Insulated Substation(GIS)를 분포정수회로기반으로 모델링하여 다양한 투입위상각에 따른 VFTO 상승률을 모의하였다. 이때, EMTP-RV를 이용하여 변압기로 전파된 VFTO를 측정하여 그 경향을 분석하였다.