• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.12
• /
• pp.68-73
• /
• 2012

In this paper, the fault current limiting characteristics of a flux-lock type superconducting fault current limiter (SFCL) with peak current limiting function were analyzed through its short-circuit tests. The setting condition for the peak current limiting operation was derived from its electrical equivalent circuit, which was dependent on the inductance ratio between the third coil and the first coil. Through the analysis on the short-circuit tests for the flux-lock type SFCLs with the different inductance ratio between the third coil and the first coil, the setting value for the peak current limiting operation of the flux-lock type SFCL with peak current limiting function could be confirmed to be adjusted with the variation of the inductance ratio between the third coil and the first coil.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.24 no.1
• /
• pp.47-51
• /
• 2011

The superconducting fault current limiter (SFCL) with a peak current limiting function according to the initial fault current with the different amplitudes was suggested. The proposed SFCL, which consists of two limiting components, causes only the first superconducting element among two limiting components to be quenched in case that the initial fault current with the lower peak amplitude happens. On the other hand, the initial fault current with the higher peak amplitude makes both the superconducting elements of two limiting components to be quenched, which contributes to the peak current limiting function of the SFCL. To confirm the fault current limiting operation of the proposed SFCL, the short-circuit tests of the SFCL according to the fault angle were carried out and its effective fault current limiting operations could be discussed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.26 no.11
• /
• pp.75-80
• /
• 2012

In this paper, the operational characteristics due to the introduction of the superconducting fault current limiter(SFCL) with a peak current limiting function were analyzed in the power distribution system. The parallel structure of the superconducting element can operate the peak current limiting function depending on the transient amplitude of fault current. We studied the operating characteristics of the introduction of the SFCL with a peak current limiting function in the power distribution system. Furthermore, we were analyzed between the SFCL with a peak current limiting function and the protection devices in the power distribution system, through the short circuit experiments.

• Progress in Superconductivity
• /
• v.12 no.1
• /
• pp.23-26
• /
• 2010

A double line commutation (DLC) type SFCL with first peak limiting function has been proposed for ideal fault current limiting operation. Very fast switching (commutation) without any arc or high voltage problems for any kind of switching device is needed for the first peak current limiting. We've tried to find suitable conditions for a successful switching of a Vacuum Interrupter (VI) with HTS elements as a Peak Current limiting Resistance (PCR).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.8
• /
• pp.499-504
• /
• 2016

In this paper, we analyzed the operational characteristics of the fault current limiting according to the amplitude of the fault current for the transformer type superconducting fault current limiter (SFCL). If the fault current happens, the superconducting element connected to the secondary coil is occurred quench and the fault current is limited. When the larger fault current occurs, the superconducting element connected to the third coil is occurred additional quench and the peak fault current is limited. We found that the fault current can be more effectively controlled through the analysis of the fault current limiting and the short-circuit tests.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.5
• /
• pp.717-722
• /
• 2016

In this paper, in order to support the peak current limiting function depending on the intensity of the fault current at the early stage of failure, a two magnetically coupled type superconducting fault current limiter (SFCL) is proposed, which includes high-Tc superconducting (HTSC) element 1, where the existing primary and secondary coils are connected to one iron core in parallel, and HTSC element 2, which is connected to the tertiary winding using an additional iron core. The results of the experiments in this study confirmed that the two magnetic coupling type SFCL having coil 1 and coil 2 connected in parallel using dual iron cores is capable of having only HTSC element 1 support the burden of the peak current when a failure occurs. The reason for this is that although HTSC element 1 was quenched and malfunctioned because the instantaneous factor of the initial fault current was large, the current flowing to coil 3 did not exceed the critical current, which would otherwise cause HTSC element 2 to be quenched and not function. In order to limit the peak current upon fault through the sequential HTSC elements, the design should allow it to have the same value as the low value of coil 1 while having coil 3 possess a higher self-inductance value than coil 2. In addition, a short-circuit simulation experiment was conducted to examine and validate the current limiting and recovery characteristics of the SFCL when the winding ratio between coil 1 and coil 2 was 0.25. Through the analysis of the short-circuit tests, the current limiting and recovery characteristics in the case of the additive polarity winding was confirmed to be superior to that of the subtractive polarity winding.

• Proceedings of the KIEE Conference
• /
• 1999.07f
• /
• pp.2470-2474
• /
• 1999

The main drawback of parallel type active power filters (APFs) is the large capacity required for harmonic compensation. This paper evaluates the APF capacity requirement for harmonic/reactive power compensation for thyristor converter load. Theoretically achievable maximum power factor under partial load is evaluated. it is shown that the APF capacity can be considerably reduced by deliberately limiting the peak current, while maintaining the filtering performance with an acceptable total harmonic current level. the minimum capacity requirement of APF with current limiting is evaluated as a function of the firing angle of thyristor converter and short circuit ratio(SCR).

• Proceedings of the KIEE Conference
• /
• 2002.11d
• /
• pp.144-146
• /
• 2002

The latest development flow of MCCB(Molded Case Circuit Breaker) is largely separated from which are high capability of interrupting compact of size and multi-ability in functions. As follow of development of industrial system. MCCB which are including communication function and having a ultimate interrupting capability is required in electrical system. to attain an effective limitation of the peak let-through current and the let-through energy, the arc has to move rapidly off the contacts and has to increase the arc voltage which mainly effect to interrupt. In this paper. we made high performance circuit breaker which including current limiting unit which is attached to the main which is simulated by CAE tool that are repulsion force and mechanical dynamics after that we tested and finally selected optimized for circuit breaker.

• Journal of the Korean Electrochemical Society
• /
• v.2 no.2
• /
• pp.93-97
• /
• 1999

From the anodic peak currents of cyclic voltammograms for Ag(I)/Ag(II) couple obtained with the variation of nitric acid concentration, Ag(I) concentration and solution temperature at a Pt electrode in concentrated nitric acid solutions, the diffusion coefficients of Ag(I) ion were evaluated to estimate the limiting current density of Ag(II)-mediated electrochemical oxidation (MEO) process, which has been effectively used for the complete destruction of hazardous organic materials. The results showed that, due to the water decomposition reaction which occurred simultaneously with the Ag(I) ion oxidation, background subtractions for the cyclic voltammograms were required to estimate the correct peak currents. The empirical relationship for the diffusion coefficient of Ag(I) was suggested as a function of solution viscosity and temperature.