• Journal of Electrical Engineering and Technology
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• v.1 no.2
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• pp.137-144
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• 2006

This paper proposes novel protection schemes for grid-connected distributed generation (DG) units using the fault location algorithm. The grid-connected DG would be influenced by abnormal distribution line conditions. Identification of the fault location for the distribution lines at the relaying point of DG helps solve the problems of the protection relays for DG. The proposed scheme first identifies fault locations using currents and voltages measured at DG and source impedance of distribution networks. Then the actual faulted feeder is identified, applying time-current characteristic curves (TCC) of overcurrent relay (OCR). The method considering the fault location and TCC of OCR might improve the performance of the conventional relays for DG. Test results show that the method prevents the superfluous operations of protection devices by discriminating the faulted feeder, whether it is a distribution line where DG is integrated or out of the line emanated from the substation to which the DGs are connected.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.709-710
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• 2007

고도의 정보화 사회에서 유비쿼터스를 기반으로 하는 IT산업이 발전함에 따라 기존의 전국적으로 광범위하게 구축되어 있는 전력인프라를 활용하는 방안이 강구되었다. 또한 사회적으로 신성장 동력산업 추진에 한전의 주도적인 역할담당이 요구되어 이를 위한 사업개발이 필요하였고 그로인하여 한전 주도하에 전력선통신 사업을 추진하게 되었다. 전세계적으로 전력선통신(Power Line Communication) 기술은 디지털 통신 기술과 네트워크 기술의 발달로 차세대 유비쿼터스 네트워크를 구축하기 위한 효과적인 기술로 대두되고 있으며 일반 통신망보다도 더 광범위하게 분포하고 네트워크화가 되어 있어 최근 몇 년간 전력선 통신 기술은 전력선 통신 모뎀과 네트워크 기술에 대해 비약적인 발전이 이루어 졌다. 한전에서는 배전계통에 설치되어 있는 배전자동화시스템에 국가 연구개발과제로 개발되어진 전력선통신 기술을 시범 적용하여 전력과 IT의 융합을 통한 전력서비스의 혁신과 新 부가가치 창출을 통하여 새로운 차원의 고객만족 서비스를 실현하기 위해 노력하고 있다.

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.279-281
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• 1998

This paper present overvoltage induced on distribution power line by lightning surge. It is important problem that overvoltage threatens credit and security of the power system. In this paper induced overvoltage was calculated. From the line being modeled in really actual practice. Also, the proper suppressing effects of a surge arrester against lightning induced voltages were suggested.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.829-831
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• 1997

We investigated configuration plan and future expectation of the power distribution test center. The example of foreign country's test center was analyzed, and the required test facilities, test line, and power source for the operation of our test center were proposed.

• JOURNAL OF ELECTRICAL WORLD
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• no.4 s.88
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• pp.44-49
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• 1984

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.2
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• pp.73-78
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• 2020

In this study, a novel reactive power control scheme is proposed to supply stable reactive power to the distribution line by compensating a ripple voltage of DC link. In a single-phase system, a magnitude of second harmonic is inevitably generated in the DC link voltage, and this phenomenon is further increased when the capacity of DC link capacitor decreases. Reactive power control was performed by controlling the d-axis current in the virtual synchronous reference frame, and the voltage control for maintaining the DC link voltage was implemented through the q-axis current control. The proposed method for compensating the ripple voltage was classified into three parts, which consist of the extraction unit of DC link voltage, high pass filter (HPF), and time delay unit. HPF removes an offset component of DC link voltage extracted from integral, and a time delay unit compensates the phase leading effect due to the HPF. The compensated DC voltage is used as feedback component of voltage control loop to supply stable reactive power. The performance of the proposed algorithm was verified through simulation and experiments. At DC link capacitance of 375 uF, the magnitude of ripple voltage decreased to 8 Vpp from 74 Vpp in the voltage control loop, and the total harmonic distortion of the current was improved.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1469-1470
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• 2015

Recently induction generator has been applied to many small hydro power plants. Induction generator needs a reactive power for magnetization. The reactive power of induction generator is being supplied from the supply side mostly. The use of induction generators in the power distribution grid can affect the power factor. The power factor of induction generator is fixed already during production. The power factor in the distribution system is due to the increase or decrease of the load rather than due to the induction generator. In this study, we analyzed how the power factor is changed according to the load increase or decrease in the distribution lines.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.229-231
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• 1999

This paper deals with electromagnetic transient modelling of wind power system embedded in distribution networks. Wind power system consists of induction generator link reactor, distribution line, and controlled load unit. The introduction of embedded wind power system presents a new set of conditions to networks both with respect to power quantify needed to be transported and power quality such as sag swell, very short interruption, and flicker. This paper investigates the transient behavior of voltage, frequency, and load flow in wind driven induction generation system embedded in distribution networks.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.10
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• pp.143-148
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• 2010

Recently, the KEPCO is constructing the PQMS(Power Quality Monitoring System) each of the distribution line and will establish the voltage sag standard based on the long time measurement data of PQMS. The voltage sag prospect is difficult for the power system manager, however, the voltage sag forecasted is very important because the damage effect of the voltage sag is very broad. This paper describes the prospect formula of the voltage sag magnitude in the PCC(Point Common Coupling) by the starting current when the high capacity equipment is connected with the distribution line. To achieve this, this paper has proposed the sag prospect formula revision of KEPCO for the reliability improvement and the proposed formula has been applied the voltage sag real case to inspect the calculation procedure and reliability.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.617-618
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• 2012

Recently as the inactive response characteristics of the existing RCD(Residual Current protective Device) used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper is proposed a prevention apparatus using neutral line voltage and semiconductor switching devices for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The proposed prevention apparatus confirms the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker(RCD) through various operation performance analysis.