• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.262-270
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• 2013

A boundary protection method for power distribution line based on equivalent boundary effect is presented in this paper. In the proposed scheme, the equivalent resonance component with a certain central frequency is sleeve-mounted at the beginning of protected zone. The 'Line Boundary' is built by using boundary effect, which is created by introducing impedance in the primary-side of line. The 'Line Boundary' is significantly different from line wave impedance. Therefore, the boundary protection principle can be applied to power distribution line without line traps. To analyze the frequency characteristic corresponding to traveling-waves of introducing impedance in the primary-side of line, distributed parameters model of equivalent resonance component is established. The results of PSCAD/EMTDC simulation prove the obvious difference of voltage high frequency component between internal faults and external faults due to equivalent resonance component, and validate the scheme.

• 대한전자공학회논문지
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• 제7권4호
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• pp.67-82
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• 1970

In this paper, formulas are developed for computing induced line voltages incommunication lines due to power line failure. Formulas are expressed in terms of fault current, mutual impedance andlength of line. Computed results are shown for various power line valtages and length of line. (Computation is done by IBM 1130-3B Computer system at Soong Sil Compute Center)

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 추계학술대회 논문집
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• pp.93-96
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• 2001

This paper proposed on the Line-Interactive UPS with power factor correction. The paper Line-Interactive UPS topology with its advantages is reviewed. Next introduces Line -Interactive UPS of the series active compensator. The series active compensator controls input currents and power factor.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 춘계학술대회 학술발표 논문집
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• pp.187-190
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• 2000

Chua's circuit is a simple electronic network which exhibits a variety of bifurcation and attractors. The circuit consists of two capacitors, an inductor, a linear resistor, and a nonlinear resistor. In this paper, a transmitter and a receiver using two identical Chua's circuits are proposed and synchronizations of a power line are investigated. Since the synchronization of the power line system is impossible by coupled synchronization, theory having both the drive-response and the coupled synchronization is proposed. As a result, the chaos synchronization has delay characteristics in the power line transmission system caused by the line parameters L and C.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.975-977
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• 2005

The generator on-line diagnosis system has been developed. This system monitor the insulation condition of stator winding by on-line measurements of partial discharge and the shorted-turn condition of rotor winding by on-line measurements of slot leakage flux. Sensor, such as SSC(Stator Slot Coupler) and flux probe are used for generator on-line diagnosis.

• 한국전자통신학회논문지
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• 제19권2호
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• pp.355-360
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• 2024

본 논문에서는 4-코일 방식의 자기공진 무선전력전송 시스템을 구현하는 데 있어서, 송전 공진코일의 끝단에서 발생하는 선간 방전현상을 연구하였다. 자기공진 무선전력전송은 급전코일, 송전 공진코일, 수전 공진코일, 부하코일로 구성되어 있다. 여기서 송전 공진코일은 급전코일에서 발생한 자기장을 증폭하여 전방의 수전 공진코일로 전달하는 역할을 한다. 큰 전력을 전송하기 위하여 급전코일에 높은 전류를 흘려주면 송전 공진코일 끝단에 높은 전압이 유기되어 선간 방전현상이 일어나게 된다. 선간 방전현상은 송전기 케이스를 손상시키게 되고, 송전기를 사용할 수 없는 상태로 만든다. 따라서 이러한 선간 방전현상을 제거하기 위하여, 선간 방전을 일으키는 송전 공진코일에 유기되는 전압을 분석하고, 해결 방안을 제시하였다.

• 전기학회논문지
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• 제63권3호
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• pp.414-417
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• 2014

At present, the demand for electric power increases, the electric power system is complicated. The size of the line-to-ground fault and the line-to-line fault occurred with complication of electric power system continue to increase, therefore several issues are raised. To address these issues effectively, the superconducting fault current limiter (SFCL) has been proposed, this study is ongoing. In this paper, we applied the SFCL in three-phase transformer and comparative analysis of the electric power burden to the SFCL. The superconductor is combined to the third winding of transformers in connection structure. In case of a third line-to-line fault, we did comparative analysis of the electric power burden to the SFCL based on the turn ratio of transformer third winding. In this case, we could confirm as the third turn ratio increased, electric power impressed to the superconducting element increased.

• 한국통신학회논문지
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• 제30권12A호
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• pp.1136-1146
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• 2005

본 논문에서는 전력선 통신을 위해 사용되는 고압 배전선로에서 통신신호 및 잡음신호에 의해 방사되는 방사전계강도를 계산하였다. 전력선 통신 네트워크의 2포트 등가모델 및 기본적인 전송선로 이론을 이용해 입력임피던스를 계산하였다. 그리고 계산된 입력임피던스를 이용해 전력선상 전류를 계산하고 최종적으로 방사전계강도를 계산하였다. 전력선의 특성임피던스가 매우커서 입력 단에서의 반사가 심하기 때문에 입력임피던스는 일정한 주기를 가지는 정재파 형태를 가진다. 계산된 전류 및 방사전계 또한 이러한 형태임을 알 수 있었다. 실제 측정한 결과계산 치와 측정치가 매우 유사함을 알 수 있었다.

• 조명전기설비학회논문지
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• 제26권7호
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• pp.77-83
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• 2012

Since power system is switching to smart grid, on-line monitoring technology has become necessary for underground distribution power cable. Therefore, the application of DTS(Distributed Temperature Sensing) technology using OFCPC(Optical Fiber Composite Power Cable) capable of monitoring underground distribution power cables has been developed. These can bring about reductions in faults and increases in operating capacity of underground distribution system. To date, the test-bed of optical fiber composite power cable on-line monitoring system has been constructed. Then, matters to be improved have been drawn through verification experiments. This paper presents the improvement and experiment results of the optical fiber composite power cable on-line monitoring system to apply to underground distribution lines in the field.

• Journal of Advanced Marine Engineering and Technology
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• 제25권4호
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• pp.889-897
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• 2001

Recently, a lot of studies on the power line communication(PLC) are being done by many companies and institutes due to its own merit which can use the power line spread widely as a communication channel. But, there are many serious problems about the harsh and unpredictable characteristics, or noise, signal distortion and attenuation to be overcome for commercialization. In this paper, the power line characteristics as the view point of communication channel are investigated and the technologies of PLC are proposed to control the power of electric machineries by using the combined method of ASK modulation and microprocessor technologies. Also experiments are carried out to ascertain performance in case of applying to electric lights control according to various distancea as an example.