• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1259-1260
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• 2015

한국의 송전선로는 154kV, 345kV, 765kV로 분류할 수 있으며, 이 중 765kV급 송전선로는 2000년대 초반 도입된 이래 대규모 발전단지와 부하밀집 지역을 잇는 주요한 설비로 자리잡아 현재까지 안정적으로 운용되고 있다. 그러나 최근 건강을 중요시 여기는 사회적 트렌드와 전자계에 대한 일반 대중들의 관심 증가로 밀양 765kV 송전선로의 건설이 지연되어 적기 건설 및 운영에 어려움을 겪고 있다. 이러한 문제를 해소하기 위해 송 변전설비 주변지역의 보상 및 지원에 관한 법률이 2014년 7월 29일부로 시행되어 전력설비 인근 지역에 거주하는 주민들의 보상을 법으로 보장하고, 원활한 관련 문제 해소를 위해 다양한 Risk Communication 방안이 검토되고 있다. 또한 송전선로에서 주로 이슈가 되는 전기환경영향에 대해 장기 전기환경 측정시스템을 구축하여 상용선로에서 1년 이상의 전기환경 DB를 집록할 예정이다. 전력설비의 전기환경은 크게 전파장해, 소음, 전자계로 구분할 수 있으며 참고 데이터로 기상요소를 측정하는데 장기 전기환경 측정시스템에서는 이 모든 전기환경 데이터를 취득할 수 있는 설비를 갖추고 있으며, 본 논문에서는 구축된 설비를 간다하게 설명하고 해당 부지에서의 전자계 값을 모의하고 실측한 결과를 수록하였다.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.1
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• pp.25-32
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• 2010

The paper proposes a hierarchical fault detection method for the high voltage equipment using a microphone array which detects the location of fault and the thermal imaging and CCD cameras which verifies the fault and stores the image, respectively. There are partial arc discharges on the faulty insulators, which generates a specific pattern of sound. Detecting the signal using the microphone array, the location of the faulty insulator can be estimated. The 6th band-pass filter was applied to remove noise signal from wind or external influence. When the mobile robot carries the thermal and CCD cameras to the possible place of the fault insulator, the fault insulators or power transmission wires can be detected by the thermal images, which are caused by the aging or natural erosion. Finally, the CCD camera captures the image of the fault insulator for the record. The detection scheme of fault location using the microphone array and the thermal images have been proved to be effective through the real experiments. As a result of this research, it becomes possible to use a mobile robot with the integrated sensors to detect the fault insulators instead of a human being.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.8
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• pp.354-360
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• 2002

The partial discharge detecting method using the ultrasonic technique has been investigated to monitor the insulation ageing of a transformer. However, the result of the studies on the ultrasonic technique for detecting of partial discharge in the operating transformer is not enough yet to utilize. This paper presents the analysis of the ultrasonic signals due to the partial discharge in a model transformer and the corona in air at a shielded high voltage room. In addition, the ultrasonic signals due to the vibration from the core, operation of the cooling pump, the fan and the OLTC at the 345㎸ power transformer, were analyzed and corona noise from overhead transmission line in 345㎸ substation were measured to remove the electrical and mechanical noises from the transformer. Furthermore, ultrasonic signal due to the partial discharge in the 154㎸ power transformer with in $C_2$$H_2$ gas warning condition was measured. The inside of the transformer was examined with care. which confirms the existence of the partial discharge source.

• International Journal of Advanced Culture Technology
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• v.7 no.4
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• pp.236-241
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• 2019

This paper will read about a multichannel frequency-modulated continuous wave (FMCW) radar sensor with switching transmit (TX) antennas is developed at W-band. To achieve a high angular resolution, a uniform linear array consisting of 5 switching-TX and 12 receive (RX) antennas is employed with the digital beamforming technique. The overall radar front-end module comprises a W-band transceiver and TX/RX antennas. A multichannel transceiver module consists of 5 up-conversion and 12 down-conversion channels, where one of the TX channels is sequentially switched ON. For developing transmitter, we developed an HPA (high power amplified) MMIC chip for W-band radar system and fabricated a transmitter module using this chip. In order to develop the W-band transmitter, we analyzed the important antenna transition structure from HPA MMIC line to W/G (Waveguide)antenna via M/S(microstrip) and fabricated it with 5 transmission channels. As a result, the output power of the transmitter was within 1 dB of the error range after analysis and measurement under normal temperature and environmental conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.257-265
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• 2011

As the competitive market system has been introduced to the electrical power trade, the priority concern would be that the price of electrical power should be reasonable. It is because, when this rule is solid, we can avoid the distortion of competition and assure the greater efficiency in management. LMP(Locational Marginal Price) means marginal price at each bus. This components consist of energy, loss and congestion cost. At this point, the LMP result that is calculated by traditional model is changeable by the location of the slack and can not be used in bilateral Transaction. This paper proposed algorithm is proved its rationality and credibility by comparing the result of the simulation of virtual 6_bus system that is calculated by traditional method, and showed that the LMP components are changed according to the Transaction Strategy. Furthermore, It shows the effect of additional congestion cost on the transmission line that has bottle neck frequently by simulation.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1769-1777
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• 2018

This paper proposes a method for optimal placement of Phasor Measurement Units (PMUs) considering system configuration and its attributes during the planning phase of PMU deployment. Each bus of the system is assessed on four diverse attributes; namely, redundancy of measurements, rotor angle and frequency monitoring of generator buses, reactive power deficiency, and maximum loading limit under transmission line outage contingency, and a consolidated 'degree of criticality' is determined using Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). The major contribution of the proposed work is the development of modified objective function which incorporates values of the degree of criticality of buses. The problem is formulated as maximization of the aggregate degree of criticality of the system. The resultant PMU configuration extends complete observability of the system and majority of the PMUs are located on critical buses. As budgetary restrictions on utilities may not allow installation PMUs even at optimal locations in a single phase, multi-horizon deployment of PMUs is also addressed. The proposed approach is tested on IEEE 14-bus, IEEE 30-bus, New England (NE) 39-bus, IEEE 57-bus and IEEE 118-bus systems and compared with some existing methods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1085-1092
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• 2010

This paper describes the development of estimating equation for under 16 aged children's exposure to habitat's magnetic field for 24 hours by using particle swarm optimization(PSO) algorithm, which was carried out by using the measured database collected from the exposure survey to Korean habitat's magnetic field as to under 16 aged Korean students such as preschooler, children in elementary school, and children in middle school. Sex, age, residence type, size of habitation site, distance from power line, and power transmission voltage are used as the input data of estimating 24 hour's personal exposure to magnetic field. And distribution of 24 hour's personal exposure to magnetic field, exposure characteristic to magnetic field, and exposure characteristic to magnetic field according to special conditions, are analyzed for under 16 aged children.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.208-213
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• 2008

In recent society, the quality of human life has improved due to the use of electric appliances and the high powered electrical equipments. However, lots of electric appliances and equipments generate the electromagnetic field hazard. Many studies have been made about the wrong behavior of machines due to electromagnetic fields, the interferences in communication equipments, the possibility of the electromagnetic field hazard in human body, etc. There exist international standards about the RF equipments (ex. mobile phone, antenna, etc.). But, many researchers involved in power frequency electric and magnetic field only propose the prudential avoidance. In this paper, induced currents in a human body model due to magnetic fields in high speed railway are calculated by two dimensional impedance method. Power frequency(60Hz) magnetic fields are calculated and induced currents are simulated by Faraday's law. Induced currents are simulated with induced voltage, human body model impedances due to Ohm's law, magnetic fields derived from Biot-Savart's law and Transmission Line Method in high speed railway.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.765-767
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• 2014

본 논문에서는 단거리 레이더용 차량 추돌 방지 24-GHz CMOS 고주파 전력 증폭기 (RF Power Amplifier)를 제안한다. 이러한 회로는 class-A 모드 증폭기로서 단간 (inter-stages) 공액 정합 (conjugate matching) 회로를 가진 공통-소스 단으로 구성되어 있다. 칩 면적을 줄이기 위해 실제 인덕터 대신 전송선(Transmission Line)을 이용하였다. 제안한 회로는 TSMC $0.13{\mu}m$ 혼성 신호/고주파 CMOS 공정 ($f_T/f_{MAX}=120/140GHz$)으로 설계하였다. 설계한 CMOS 고주파 전력 증폭기는 최근 발표된 연구결과에 비해 약 22dB의 높은 전력이득 및 7.1%의 높은 PAE 특성을 보였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.542-550
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• 2001

In this paper, a channel combiner is designed to combine two adjacent digital TV channels without interference to transmit these channels with one broadband antenna. A constant impedance type combiner, consisting of two identical bandpass filters and two identical 3 dB power combiners, is chosen as a channel combiner. The bandpass filter used in the channel combiner also suppresses out-of-band signal caused by digital transmitter's non-linearity. H-plane type bandpass filters and branch-line fewer combiners are adopted in the design. The simulated results of the designed bandpass filter and power combiner show excellent agreement with the theoretical results. Finally, a channel combiner is designed by combining filters with rover combiners and the characteristics are simulated. It is shown that the designed channel combiner shows excellent performance.