• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.82-84
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• 2000

This paper deals with a evaluation algorithm of interruption cost in distribution systems in the case where Dispersed Storage and Generation (DSG) systems are interconnected with the distribution systems. If DSG systems are operated as the function of the load levelling in distribution systems at the normal conditions and as the uninterruptible power supply in fault areas at the emergency conditions, the reliability improvement of the distribution systems can be expected. In other words, the benefit can be represented by the cost avoiding interruption according to the operation of DSG systems when a fault is occurred. Therefore, this paper presents the evaluation algorithm for interruption cost in order to evaluate the benefit for the uninterruptible power supply of DSG systems in a quantitative manner.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.61-63
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• 1995

The main factors to bring out the power failure are trouble and operation power failure, the operation power failure of these includes about 85%. So, it is required that the without interruption of service method reduce the operation power failure. If we develop the without interruption of service method, the operation power failure will reduce greatly. It is necessary to develop the without interruption of service method which it solve various trobles (dissatisfacting solution of customer, sales revenue augmentation, and the reduction of the power failure negotiation work). The results of study are drawing up of the specification for temporary transmission methods, it of the working methods for them, and the scrutiny of the technology contents for them.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.413-414
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• 2006

This study was aimed to verify the stable interruption characteristics between power collector and 3rd rail type conductor rail for the Korean-standardized rubber-tired AGT light rail vehicle. At the test track for the Korean-standardized rubber-tired AGT light rail vehicle, interruption ratios, stresses, vibrations, and contact force variations were measured by test conditions, having various train speed. As the results, it was verified that developed 3rd rail type conductor maintains interruption characteristics, which can supply stable electric power.

• 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.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1947-1954
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• 2007

This paper describes the development of a high-performance single-phase line-interactive Dynamic voltage Restorer, which is composed of an H-bridge inverter and super-capacitors. The operational feasibility was verified through computer simulations with PSCAD/EMTDC software, and experimental works with 3kVA prototype. The developed system can compensates the input voltage sag and interruption within 2ms, in which the maximum allowable duration of voltage interruption is 1.5 seconds. It can be effectively used to compensate the voltage interruption in the sensitive load, such as computer, communication equipment, automation equipment, and medical equipment. The developed system has a simple structure to be easily implemented with commercially available components and to be highly reliable in operation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.1954-1961
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• 2009

This paper describes the development of a three-phase line-interactive dynamic voltage restorer with hybrid detection method, which is composed of three H-bridge inverter modules and super-capacitors. The operational feasibility was verified through computer simulations with PSCAD/EMTDC software, and experimental works with a 3kVA prototype. The developed system can compensate the input voltage sag and interruption within 2ms. The maximum allowable duration of voltage interruption is about 4 seconds. The developed system can be effectively used to compensate the voltage interruption in the sensitive load, such as computer, communication devices, and automation devices, and medical equipment. The developed system has a simple structure to be easily implemented with commercially available components, and to be highly reliable in operation.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.10
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• pp.528-533
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• 2006

To analyze the small current interruption performance for the gas circuit breakers, the gas density and electric field intensity should be calculated. In this paper, the FVFLIC method is used for the gas flow analysis and the FEM for the electric field analysis. Then, the dielectric withstanding voltage is evaluated by the empirical formulation or Streamer theory. By comparing the calculated dielectric strength with the test result, it is found that both methods show good prediction capability for the small current interruption performance. Especially, when both methods predict the same interrupting performance, the prediction is in accordance with the experimental result.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.215-219
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• 2019

Development of DC interruption technology is being studied actively for enhanced DC grid reliability and stability. In this study, coil type superconductor DC circuit breaker was proposed as DC interruption. It is integration technology that combined current-limiting technique using superconductor and cut-off technique using mechanical DC circuit breaker. Superconductor was applied to the coil type. In simulation, Mayr arc model was applied to realize the arc characteristic in the mechanical DC circuit breaker. PSCAD/EMTDC had used to model and perform the simulation. To find out the protection range of coil type superconductor DCCB, the working operation have analyzed based on the rated voltage of DCCB. The results confirmed that, according to apply the limiting device, the protection range was increased in twice. Therefore, the probability of failure of interruption has lowered significantly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.2A
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• pp.174-185
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• 2010

A seamless handover between the 3G LTE and legacy 3G system is required for the smooth deployment of the 3G LTE system which is the next generation cellular network system. Especially on voice call handover, the service interruption time is very sensitive for user's satisfaction and therefore, a seamless voice call handover scheme is necessarily required. However, handover between the 3G LTE and the 3G CS system is hard to be achieved due to the lack of interface between two systems and the restriction of radio resource. In this paper, a new network entity called SCSE is proposed and inter-working between the 3G LTE and the 3G CS systems is enabled. Also contributed to the feature of the SCSE, the handover procedure is simplified and the service interruption time is minimized as a consequence. The evaluation result shows that the proposed SCSE scheme exclusively meets the service interruption time requirement which is smaller than 300 ms.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.4
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• pp.357-362
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• 2010

Electricity can be directly generated from organic matter even wastewaters using a microbial fuel cell. To achieve high power in MFCs, finding factors decreasing activation and Ohmic losses is very important. In this study we determined activation loss at the anode and cathode and Ohmic loss using the current interruption technique in a H-type MFC. Activation loss at the cathode was four times higher that that of anode activation loss even if pt-coated carbon (0.5 $mg/cm^2$;10%Pt) was used as the cathode. Ohmic loss determined using current interruption technique (1146 ${\Omega}$) was almost same as the internal resistance (1167 ${\Omega}$) measured using AC impedance. The sum of activation losses at the anode and cathode was the same as the value of activation loss of the cell.