• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.4
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• pp.595-599
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• 2018

Interruption system with the transformer type superconducting fault current limiter(TSFCL) is proposed in this paper. The interruption system with a TSFCL is a technology that it maximizes the interruption function of a mechanical DC circuit breaker using a transformer and a superconducting fault current limiter. By a TSFCL, the system limits the fault current till the breakable current range in the fault state. Therefore, the fault current could be cut off by a mechanical DC circuit breaker. The Interruption system with a TSFCL were designed using PSCAD/EMTDC. In addition, the Interruption system with a TSFCL was applied to the DC test circuit to analyze characteristics of a current-limiting and a interruption operation. The simulation results showed that the Interruption system with a TSFCL interrupted the fault current in a stable when a fault occurred. Also, The current-limiting rate of the Interruption system with a TSFCL was approximately 69.55%, and the interruption time was less than 8 ms.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.7
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• pp.362-368
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• 2006

This paper presents the results of a small capacitive current interruption test for the three types of interrupter which are called 'serial type', 'parallel/separated type' and 'puffer type' according to the arrangement of the thermal expansion chamber and the puffer cylinder. After the preconditioning test the small current interruption capability of the 'puffer type' decreased, on the contrary, that of the hybrid interrupters increased. A number of reignition have been occurred in the 'serial type' hybrid interrupter and the change of small current interruption capability after preconditioning test is mainly influenced by the structure of interrupter. Finally it has been proved that the 'parallel/separated type' hybrid interrupter has the best interruption performance through the verification tests.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.3
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• pp.166-172
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• 2004

Arc Fault Current is an electric discharge which is occurred in two opposite electrode. In this Paper, arc current control algorithm is designed for the interruption of arc fault current which is occurred in the low voltage network. This arc Is one of the main causes of electric fire. Arc fault in electrical network has the characteristics of low current, high impedance and high frequency. Conventional control algorithm does not have the arc current interrupt function. Hence, Control algorithm of arc current is designed for the interruption of arc fault current which has the modified arc characteristics.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.384-386
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• 2006

In this paper, arc current controller is designed for the interruption of arc fault current which is occurred in the low voltage network. Arc in electrical network have the characteristics of low current, high impedance and high frequency. Conventional controller does not have the arc current interrupt function. Hence, arc current controller is designed for the interruption of arc fault current.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.7
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• pp.331-337
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• 2001

With the increasing reliability of analysis schemes and the dramatically increased calculating speed, the computer simulation has become and indispensable process to predict the interruption capacity of circuit breakers. Generally, circuit breakers have to possess both the small current and large current interruption abilities and the circuit breaker designers need to evaluate its capacities to save the time and the expense. The analysis of small current and the large current interruption performances have been considered separately because the phenomena occurring in a interrupter are quite different. To analyze the dielectric recovery after large current interruption many physical phenomena such as heat transfer, convection and arc radiation, the nozzle ablation, the ionization of high temperature SF(sub)6 gas, the electric and themagnetic forces and so forth mush be considered. However, in the analysis of small current interruption performance only the cold gas flow analysis needs to be carried out because the capacitive current is to small that the influence from the current can be neglected. In this paper, an empirical equation which is obtained from a series of tests to estimate the dielectric recovery strength has been applied to a real circuit breaker. The results of analysis have been compared with the test results and the reliability has been investigated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.9
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• pp.109-113
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• 2007

In this paper, an arc current controller was designed for the interruption of arc fault currents occurred in a low voltage network. Arc in an electrical network represents the characteristics of low current, high impedance, and high frequency. Conventional controllers do not have arc current interrupt functions. Thus, an arc current controller was designed for the interruption of arc fault currents.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1961-1965
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• 2003

The flow analysis is needed to verify the physical phenomena through interruption processes for improving the capacity and the reliability of gas circuit breakers. Moreover the small current interruption performance of GCBs could be predicted by coupling the flow characteristics with the electric field one. In this paper, the unsteady flow characteristics and the traveling trajectory are depicted with a commercial CFD code, PHOENICS, programmed for moving motion of objects. In order to validate computational results, the measured pressure data in cylinder and in front of arcing contact are compared with the test results of small current interruption.

• Journal of Electrical Engineering and Technology
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• v.8 no.2
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• pp.354-358
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• 2013

This paper discusses the analysis of arc conductance in a gas circuit breaker (GCB) during current interruption process and the investigation method of the interruption capability. There are some limitations in the application of the computational fluid dynamics (CFD) for the implementation of an arc model around the current zero, despite the fact that it gives good results for the high-current phase arc. In this study, we improved the accuracy in the analysis of the interruption performance by attempting the method using CFD and a mathematical arc model. The arc conductance at 200 ns before current zero (G-200ns) is selected as the indicator to predict the current interruption of the Short Line Fault (SLF). Finally, the proposed method is verified by applying to the actual circuit breakers which have different interruption performances.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.8
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• pp.384-391
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• 2001

The insulation strength between contacts after current interruption to the transient recovery voltage i.e., the dielectric recovery strength should be estimated for the evaluation of the small capacitive current interruption capability. Many authors have used theoretical and semi-experimental approaches to evaluate the transient breakdown voltage after the current interruption. Moreover, an empirical equation, which is obtained from a series of tests, has been used to estimated the dielectric recovery strength. Un this paper, the theoretical method which is generated from the streamer theory has been applied to real circuit breakers in order to evaluated the interruption capability. The results of analysis have been compared with the test results and the reliability has been investigated.

• Progress in Superconductivity and Cryogenics
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• v.19 no.4
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• pp.40-44
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• 2017

This paper analyzed the fault current limiting characteristics of the previously proposed transformer superconducting fault current limiter (TSFCL) interruption system according to its transformer type. The TSFCL interruption system is an interruption technology that combines a TSFCL, which uses a transformer and a superconductor, and a mechanical DC circuit breaker. This technology first limits the fault current using the inductance of the transformer winding and the quench characteristics of the superconductor. The limited fault current is then interrupted by a mechanical DC circuit breaker. The magnitude of the limited fault current can be controlled by the quench resistance of the superconductor in the TSFCL and the turns ratio of the transformer. When the fault current is controlled using a superconductor, additional costs are incurred due to the cooling vessel and the length of the superconductor. When the fault current is controlled using step-up and step-down transformers, however, it is possible to control the fault current more economically than using the superconductor. The TSFCL interruption system was designed using PSCAD/EMTDC-based analysis software, and the fault current limiting characteristics according to the type of the transformer were analyzed. The turns ratios of the step-up and step-down transformers were set to 1:2 and 2:1. The results were compared with those of a transformer with a 1:1 turns ratio.