Detailed Study on Insulation Coordination of a 25kV Power System Connected with a VCB and Transformer

Baek, Byung-San,Kim, Yong-Han The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.3

Recently, unusual transformer failures have been reported in 25kV power systems connected with a VCB and transformer. In this study, performance of the protection system, dielectric strength of the transformers, characteristics of switching surges and resonance phenomena were analysed and assessed. All investigations regarding the insulation breakdown of the transformers were carried out by simulations, laboratory tests, factory tests and on-site measurements in order to thoroughly investigate the root causes. Furthermore, experimental methods for investigating the resonance phenomenon were derived and tests were conducted applying the derived method to recreate the phenomenon in the transformer. It is found that resonance between the transformer and switching surge generated by closing a VCB can initiate the breakdown of internal windings of a transformer.

Detailed Study on Insulation Coordination of a 25kV Power System Connected with a VCB and Transformer

Byung-San Baek,Yong-Han Kim 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.3

Recently, unusual transformer failures have been reported in 25kV power systems connected with a VCB and transformer. In this study, performance of the protection system, dielectric strength of the transformers, characteristics of switching surges and resonance phenomena were analysed and assessed. All investigations regarding the insulation breakdown of the transformers were carried out by simulations, laboratory tests, factory tests and on-site measurements in order to thoroughly investigate the root causes. Furthermore, experimental methods for investigating the resonance phenomenon were derived and tests were conducted applying the derived method to recreate the phenomenon in the transformer. It is found that resonance between the transformer and switching surge generated by closing a VCB can initiate the breakdown of internal windings of a transformer.

경량전철 전력공급시스템의 용량 산정에 관한 연구

백병산(Baek Byung-San),서광덕(Seo Kwang-Duk),김종구(Kim Jong-Koo) 한국철도학회 2000 한국철도학회 학술발표대회논문집 Vol.- No.-

This paper describes the capacity calculation of power supply system for Light Rail Transit. Three factors are considered for the design i.e. substation arrangements, line configuration and substation power capacity. In this study, we considered all of them for capacity calculation of power supply system for LRT. At first, DC-fed-traction system is introduced on an outline, a characteristics of train and fed network, and design method of substation arrangements. Optimal design procedures are described, and program for capacity calculation of the system is presented. In addition, the computer simulated results are compared with the conventional simple calculation method.

A NEW CONTROL METHOD FOR CURRENT SHARING IN THE 12-PULSE PHASE-CONTROLLED RECTIFIER

Min,Byung-Gwon,Baek,Byung-San,Won,Chung-Yuen 성균관대학교 1998 학술회의지원논문목록집 Vol.1998 No.-

This paper presents the new current sharing control method of a 12-Pulse phase-controlled rectifier(PCR) for a UPS. The control circuit of tht l2-Pulse PCR with a paralled operating rectifier system is proposed to balance input currents and to reduce the harmonics of input currents. The PCR is used widely in the industrial world. since its cost is much lower than that of the PWM converter and the composition of control circuits is simple. This system is developed and tested for a 3-phase 400KVA UPS system and the experimental results in this application are included

경전철 직류급전계통을 위한 디지털 보호제어장치의 개발 및 적용에 관한 연구

백병산,김재철,Baek, Byung-San,Kim, Jae-Chul 한국조명전기설비학회 2005 조명·전기설비학회논문지 Vol.19 No.2

본 논문은 경전철 급전시스템을 위한 직류보호제어장치의 개발 및 적용에 관한 것이다. 이를 위하여 직류급전계통의 단락특성을 이론과 실측자료를 이용하여 분석하였으며, 사고전류를 검출하는 기법의 개선안을 제시하여 직류 보호계전장치를 개발하였다 특히 계전기능 중 가장 중요한 고장선택계전기(50F)의 계전알고리즘을 개선하여 개발하였고, 이를 경북 경산 경전철 시험선에 설치하여 운전 중이다. 직류 보호계전기를 현장에 적용하기 위하여 그동안 불분명하고 명확하지 않았던 규정 및 규격을 개발과정에서 명확하게 정리하였다. 또한 특성시험과 EMC시험 규정 중 일부항목에 대해 시험방법이 제정되어있지 않아 IEC 규정의 분석을 통하여 객관적이고 타당한 시험회로, 방법 및 평가방법을 제안하였다. The DC protection and control device for the feeding system of a Light Rail Transit(LRT) system is developed. For the development, the short circuit characteristics in the system are analyzed. As a result a protection algorithm for the DC fault selective relay (50F) is newly proposed, and principles of the DC fault selective relay, Line Test Device (LTD), DC Over Current Relay (DC OCR) are introduced From the development, the specifications and codes used to be unclear have become clarified and summarized. Moreover, the methods to examine the protective characteristics and Electromagnetic Compatibility (EMC) are established Finally, the performance and the effectiveness of the developed protective relay have been verified with the test based on IEC. For the reliability of the system, the relay has been installed and is being operated at the test track of the LRT system at Gyeong-San.

노인복지관 이용 노인의 코로나19에 대한 인식유형 연구

유병선(Yoo, Byung-Sun),전희정(Jeon, Hee-Jeong),이민아(Lee Minah),장백산(Jang Baek san) 한국통합사례관리학회 2021 한국케어매니지먼트연구 Vol.- No.40

본 연구의 목적은 노인복지관 이용 노인들의 코로나19에 대한 주관적 인식을 유형화하고, 유형별 특성을 파악 하는 것이다. 이를 위해 경기도에 소재한 노인복지관 이용노인 17명을 대상으로 Q방법을 활용하여 조사를 실시 하였다. 분석결과, 코로나19에 대한 노인복지관 이용노인의 인식유형은 세 유형으로 나타났다. 제 1유형은 ‘적극적 대처형’으로 노인복지관 휴관이나 서비스 이용제한으로 무기력하게 생활하기보다는 개별적으로 운동이나 취미생활 등을 하면서, 보다 적극적이고 긍정적으로 코로나19로 인한 어려운 상황에 대처하는 유형이다. 제 2유형 은 ‘맞춤형 서비스 요구형’으로 코로나19 감염에 대한 걱정은 크지 않지만, 외부활동 제한으로 건강악화나 신체 기능 저하를 호소하며, 비대면이나 소규모 프로그램 확대 등 문제상황에 대응하는 맞춤형 서비스를 요구하는 유 형이다. 제 3유형은 ‘감염불안형’으로 감염에 대한 걱정이 매우 크며, 또한 노인복지관 이용이나 외출제한으로 인한 어려움이나 불안, 우울 등을 가장 크게 느끼는 유형이다. 이러한 연구결과를 바탕으로 코로나19와 같은 감 염병 발생 상황에서 노인들의 욕구에 대응할 수 있는 정책제언을 제시하였다. The purpose of this study is to categorize the subjective perceptions of Corona 19 among the elderly who use elderly welfare centers and to understand the characteristics of each type. For this, the Q method was used, and a survey was conducted on 17 elderly people using the elderly welfare center located in Gyeonggi-do. As a result of the analysis, there were three types of perceptions of the elderly using elderly welfare centers about Corona 19. The first type is the active coping type , which is a type that actively responds while exercising and hobbies individually. The second type is customized service demand type , which requires customized services to respond to problems or situations caused by corona such as non-face-to-face or small programs. The third type is infectious anxiety type and is very worried about infection. Also, it is the type that feels the most difficulty, anxiety, or depression due to restrictions on the use of welfare centers. Based on these research results, policy suggestions for coping with and supporting infectious diseases in the future were presented.

A NEW CONTROL METHOD FOR CURRENT SHARING IN THE 12-PULSE PHASE-CONTROLLED RECTIFIER

Byoung-Gwon. Min,Byung-San Baek,Chung-Yuen Won 전력전자학회 1998 ICPE(ISPE)논문집 Vol.- No.-

This paper presents the new current sharing control method of a 12-Pulse phase-controlled rectifier(PCR) for a UPS The control circuit of the 12-Pulse PCR with a parallel operating rectifier system is proposed to balance input currents and to reduce the harmonics of input currents.<br/> The PCR is used widely in the industrial world, since its cost is much lower than that of the PWM converter and the composition of control circuits is simple.<br/> This system is developed and tested for a 3-phase 400KVA UPS system and the experimental results in this application are included.

Design and Assessment of DC Traction Power Supply System for Light Rail Transit

백병산,문종필,최준호,김재철,Baek, Byung-San,Moon, Jong-Fil,Choi, Joon-Ho,Kim, Jae-Chul The Korean Institute of IIIuminating and Electrica 2006 조명·전기설비학회논문지 Vol.20 No.4

전기철도 급전시스템의 설계와 평가에 관련하여 어려운 점은 고려해야 할 요소들이 많고, 시스템적 접근이 요구되나 단편적인 논문과 엔지니어링 측면의 접근이 대부분이다. 본 논문에서는 전기철도 시스템 중 국내외에서 최근 활발히 추진되고 있는 경량전철을 위한 직류 급전시스템의 설계 및 그의 적정성을 평가하는 기법을 체계화하였다. 먼저, 급전 시스템의 구성요소인 급전 변전소와 부하인 차량과 그리고 전력선을 포함한 전체 시스템의 특성파악하고 분석하였다. 실제 계통과 동일하게 모델링하기 위하여 축약 및 등가화를 하였으며, 등가화한 시스템을 해석하기 위한 방안으로 노드방정식과 반복접근법을 적용하였으며, 이를 체계화하여 모의절차, 평가 및 설계방법을 제시하였다. 제시한 알고리즘 및 설계절차에 따라 프로그램을 개발하였으며 사례연구를 통하여 그 유효성을 입증하였다. For the design of DC traction power supply system at new Light Rail Transit(LRT) construction, it is very important to determine system configuration, location and power capacity of substation. However, a LRT system consists of a number of subsystems such as train movement, power supply and traction drives, which inevitably contains many complexities and diversities. The objective of this paper is to clarify and systematize the design procedure and its assessment for the electrification system of a LRT line. This paper discusses in detail our approach to system design and its assessment. The whole DC-feeding network configuration, characteristics of a train, and design method of substation arrangements is thoroughly investigated for the design. As a result of the investigations, the design procedure is clarified and systematized and a computer program for the design and evaluation of the system is developed using the most suitable iterative method with nodal equation. To verify the proposed design and its assessment procedure, case studies for the DC traction power supply system of a planed Korean LRT line are performed.

배선용차단기 트립부의 동특성 해석기술 개발

강종성(Jong-Sung Kang),백병산(Byung-San Baek),곽철희(Chul-Hee Kwak) 대한전기학회 2011 대한전기학회 학술대회 논문집 Vol.2011 No.7

Maximum Solar Energy Tracking System에서의 최적정수산정에 관한 연구

황영문(Young-moon Hwang),백병산(Byung-san Baek),성백주(Baek-joo Sung) 대한전기학회 1990 대한전기학회 학술대회 논문집 Vol.1990 No.7