• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.225-229
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• 2012

This paper proposes a reduced-scale simulator that can replace numerical analytic methods for the estimation of potential distribution caused by ground faults in various grounding systems. The simulator consists of a hemispherical electrolytic tank, a three-dimensional potential probe, a grounding electrode, and a data acquisition module. The potential distribution is measured using a potentiometer with a position-tracing function when a test current flows to the grounding electrode. Using the simulator, we could clearly analyze the potential distribution for a reduced- scale model by one-eightieth of the buried depth and length of the grounding rod and grounding grid. Once both the shape of the grounding electrode and the fault current are known, the actual potential distribution can be estimated.

• Proceedings of the Korea Society for Simulation Conference
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• 2003.11a
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• pp.27-34
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• 2003

A distributed server cluster system is a cost-effective system to provide a service application for clients with reliable, scalable, available, and fault-tolerant features. In order to provide high quality services, it is necessary to evaluate service performances, tune the server system, and analyze performances. In this paper, we propose a simulator to generate workloads based on statistic configuration according to estimated application traffics, apply workload scheduling algorithms, and evaluate the simulation results. We introduce the simulator design modelling and architecture. By using flexible parameters, the simulator is able to generate various patterns of workloads with different statistics, and configure system environments such as the number of server nodes, system resources considered, and their capacities. With this simulator, we introduce two scenarios: one is to find appropriate thresholds for the best performance of cluster system, and the other is to find the suitable scheduling algorithm for workload characteristics of service applications.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.110-112
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• 1999

Recently the substation automation is actively researched at each country. Since the substation automation is an integrated system that consist of electrical, electronic and computer technologies, performance evaluation is very important to inspect the developed system's applicable possibility for real power system. Most studies are verified using computer simulation, because it is hard to apply them to real power systems. Therefore development of a substation simulator is necessary for the performance evaluation of many application systems such as operator aid system. This paper introduces a substation simulator. An intelligent fault diagnosis and restorative control expert system is also introduced UDP/IP is applied as a protocol for data transport between expert system and SC(station computer). As to the Graphic User Interface, C++ Language and Visual Basic is used in the Windows NT operating system together with four Pentium II systems.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.182-184
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• 2006

A down-scaled simulator is developed to simulate typical faults in induction motor such as short-turn stator winding, broken rotor bar, dynamic and static air-gap eccentricity, bearing trouble, and mechanical unbalance. The simulator is used as an initial builder to develop design algorithm for real-time faults detecting system by processing an abnormal signal and characteristics in each fault.

• The Journal of the Acoustical Society of Korea
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• v.18 no.1
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• pp.92-96
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• 1999

As CMOS technologies have been rapidly developed, bridging faults have been relatively increased. IDDQ testing is a current testing methodology which can enhance reliability of the circuit since it efficiently detects bridging faults that are difficult to detect by functional testing. In this paper we consider internal bridging faults occurred in each gate of logic circuits under test and finally develop a fault simulator for IDDQ testing to detect assumed bridging faults.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.103-105
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• 1996

This paper describes real time dynamic tests on the digital distance relay using new digital test system including RTDS(Real Time Digital Simulator) in KEPRI. The RTDS is developed by the Manitoba HVDC Research Centre and consists of specialized hardware and software which allows transients simulation of electrical power systems in real time. From high impedance fault test, it is known that the characteristics of distance reach is influenced by load flow. A detailed discussion of relay test using the RTDS simulator, high impedance faults and test results are included in the paper.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.38-39
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• 2016

Most of fires are electric fires and 78.65% of those fires are caused by electric arc fault. This series arc fault can be caused not only by decrepit wire, pressed wire or contact badness etc. anywhere we use electricity. There are signs of heat release and flame discharge before the arc fire accident happens. This paper proposes a circuit topology for alarm system of series arc fault. We also verify the qualification of system through various arc fault simulator.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.442_443
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• 2009

A large wind farm should satisfy the requirements for a grid and accomplish the optimization of the wind farm system. In that point of view, the wind farm intertie protection system, which must consider the Fault Ride-Through (FRT) requirement for more reliable protection, should be improved. This paper proposes a modified distance relay suitable for protection of a wind farm intertie considering a FRT requirement. The frequency change is used to discriminate the intertie fault from a outside zone fault. The performance of the proposed algorithm is verified using a PSCAD/EMTDC simulator.

• Journal of Mechanical Science and Technology
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• v.19 no.3
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• pp.846-859
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• 2005

Support vector machines (SVMs) have become one of the most popular approaches to learning from examples and have many potential applications in science and engineering. However, their applications in fault diagnosis of rotating machinery are rather limited. Most of the published papers focus on some special fault diagnoses. This study covers the overall diagnosis procedures on most of the faults experienced in rotating machinery and examines the performance of different SVMs strategies. The excellent characteristics of SVMs are demonstrated by comparing the results obtained by artificial neural networks (ANNs) using vibration signals of a fault simulator.

• Journal of the Korea Society of Computer and Information
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• v.20 no.10
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• pp.1-5
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• 2015

Based on the dual hardware and software with distributed recovery blocks, the centralized type fault tolerant store management system(SMS) was proposed. As a result of trade off study related to mutiplex hardware system design, dual single board computer(SBC) was adapted. To verify redundancy function of the proposed structure, the prototype SMS and weapon simulator were used. The proposed SMS operated normally without being affected by a primary SBC failure. The switching time from primary SBC to shadow SBC was within 200 ms. The reliability of the proposed SMS was predicted and compared with the non fault tolerant SMS, thereby it was proved that the proposed SMS has a higher reliability than the non fault tolerant system within effective range.