• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.6
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• pp.40-47
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• 2007

High speed electric trains have nonlinear loads including converters and inverters for the control synchronous motors. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. Harmonic simulations are performed to evaluate the harmonic voltage and current distortions throughout the system. This paper provides an in depth analysis on harmonics field measurement of the high speed electric train loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE Std. 519-l992, and harmonics simulation using EDSA program for the case study.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.815-825
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• 2015

DNP3(Distributed Network Protocol) is one of the most representative protocols which is used in SCADA(Supervisory Control and Data Acquisition) system. IEC 62351 is listing the integrity, confidentiality, availability and non-repudiation or accountability as the security requirement. However, IEEE Std. 1815 that is DNP3 standards does not define a mechanism for non-repudiation or accountability. In this paper, we propose a non-repudiation of origin technique about the sender of critical ASDU and implement the proposed scheme using software such as OpenSSL and SCADA source code library.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.218-221
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• 2005

Grounding electrodes as discharge paths to the earth are normally used to ensure the safety of human body and facilities from the over-voltages in distribution power system, and each grounding mode has a prescribed ground resistance value respectively which is applied by the utilities. As the various electrodes for distribution power system are recently developing to improve the performance of them and resolve the problem of space restriction, it is necessary to measure and investigate the safety of human body of developed electrodes. Therefore, in this paper, we provide briefly a technical comparison of two standards, i.e. IEEE Std 80 and the IEC 479-1, and describe the configuration of safety measurement system which can measure the step voltage and the touch voltage of grounding electrodes based on IEEE Std 80.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.53-60
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• 2001

This paper presents a graphical method for hazard assessment of electric shock by safety criteria. For the human body to be safety actual body current should not exceed safety criteria, i.e. allowable body current. The assessment method presented in this paper is based m the safety criteria of the IEEE Standard 80 as well as the IEC 479-1. The hazard can be assessed in terms of alterable touch voltages instead of alterable body current. Thus, the hazard assessment of given electric shock condition is referred to a procedure by which the actual touch voltages are compared with the allowable (safe) touch voltages. Since the IEC 479-1 safety criteria are nonlinear, the graphical method is presented for the hazard assessment. Body current and body voltage are calculated with the allowable touch voltage. A comparison of the safety criteria of two widely accepted standards, i.e. the IEEE Std 80 End the IEC 479-1 is proposed. Also Thevenin equivalent resistance is obtained from electric shock model expressed by two-port earth-grid-foot system. On the basis of calculated results, the allowable touch voltage, the body current and the body voltage we can conduct the hazard or safety assessment and estimate the severity of electric shock.

• Journal of electromagnetic engineering and science
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• v.4 no.3
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• pp.97-101
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• 2004

Complex permittivities of reference liquids were measured by a liquid holder of slotted coaxial line with a movable probe at mobile communication frequencies. The validity of the liquid measurement system was checked by experimental tests with the reference liquids proposed in IEEE Std. 1528-200X or IEC 106/61/CDV.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.66-68
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• 2007

The regulatory guide, RG-1.204 and its underlying or confirmatory research, NUREG/CR-6866 were studied for Korean application to LPGS of NPPs. However they excluded the application to that of NPPs. So US-NRC approved selectively industrial standards to that of NPPs on Nov 2005. It is necessary to understand the basis of regulatory technology related regulatory positions on LPGS and important to implement the guidance on LPGS as a resonable standard. The paper is examined what and how state of the art of relevant technology applied to the LPGS as well as the trip-out events related to electrical system were involved with LPGS. We reviewed the relevant standards applicable to Korean NPPs. Following are concluded to recommend. (1) IEEE 510-1050 is recommended as a guide for I&C grounding against EMI and lighting transients (2) IEEE Std-665, 510-666, Std-C62.23 for electrical grounding against voltage surges and lighting transients (3) Inspection should be thoroughly be implemented a frequency of 3-5 year period according to NFPA780 or KSC-IEC 61024.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.344-353
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• 2008

To apply the appropriate new grounding system to domestic power system, safety has to be guaranteed under the given circumstances. It is not possible to decide the safety of grounding systems by the experimental test because safety experiments directly relate to the human life and the installed electric machines. Therefore, the computer simulation program to decide the safety of grounding systems based on the IEC standard systems, has to be developed. This paper proposes the computer simulation based method to decide the safety of grounding system with the concepts of touch voltage, step voltage, human resistivity, and applied electric current according to the several conditions of human body located in the corresponding grounding systems. The proposed method is implemented by Matlab/Simulink and Visual C++ programming tools for its visualization.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.10
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• pp.54-59
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• 2015

In this paper, we evaluate safety of grounding system which is designed according to IEC standards. Safety assessment of construction site and grounding system of building is needed before construction for the safety of human in building. Until now, in case of domestic field, design of grounding system is proceeded based on methods which are proposed in IEEE Std. 80. In other words, it is not in the situation that grounding system is designed based on IEC standards. Therefore, we propose a method which designs grounding system and evaluates safety of it according to IEC standards. We measure ground resistance of construction site using measuring equipment of ground resistance. Using this value, soil structure and ground resistivity are obtained through program analysis. CDEGS program of SES company is used for simulation analysis.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.59-66
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• 2011

In electric power system, the circuit breaker is not operated when the higher voltage then the rated TRV(transient Recovery Voltage) appeared in the circuit breaking, The TRV of a circuit breaker means the characteristics of reignition by the arc between two poles. and is decided by the value of connecting Impedance. In this paper we of carried out many kinds of experiments varying the types of bus, the types of installation, the length of installation between 22.9 [kV] level circuit breaker and MTR in general 154/22.9[kV] system, We also simulated the characteristics of TRV using EMTP-RV program. The suitability of TRV in assessed by Uc, RRRV(Rate of Rise of Recovery Voltage) which are defined by the international guide, IEC62271-100. The values of RRRV gained from the cable-made bus are 590[%] lesser than those from the NSPB-made bus respectively. So the triangled type is more rational in the aspect of TRV.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.105-106
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• 2011

전력계통에서 비선형부하와 시변부하 사용의 증가 및 분산전원의 보급 증가로 전력품질(power quality)에 대한 관심이 증대되고 있다. 전력계통에서 전력품질은 전력신호를 통해 모니터링이 가능하다. 하지만 전력신호 상시 관측을 통한 전력품 모니터링은 많은 신호 데이터양이 필요하여 전력 신호 압축이 요구된다. 이에 따라 본 연구에서는 신호 압축 성능이 우수한 DCT(discrete cosine transform)기법을 이용하여 전력신호를 압축, 복원하는 방법을 제안한다. 그리고 DSP (digital signal processor) 보드를 통해서 압축 저장 된 신호를 오차 범위 5% 이내로 복원한다. 따라서 정전과 같은 이벤트(event)가 발생하였을 때 특정시간, 장소에서의 전압과 전류 파형을 볼 수 있게 한다. IEC 61000-4-30, IEEE std 1159에 근거하여 Matlab 프로그램 상에서의 성능을 평가하고 DSP보드를 이용하여 DCT를 이용한 데이터압축 시스템을 구현하였다.