http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Hyeongwook Lee,Seunghyun Boo,Gunyoung Kim,Bomson Lee 한국전자파학회JEES 2020 Journal of Electromagnetic Engineering and Science Vol.20 No.1
This paper presents a method for solving receiver misalignment (axial or angular) problems in wireless power transfer systems using a multiple-input single-output system. The optimum magnitudes and phases of the transmitter voltages and receiver load for maximum efficiency are derived in convenient analytical forms when negligible mutual couplings between transmitters. These solutions are validated by genetic algorithm optimization and electromagnetic-simulation results for a design ex-ample of two transmitters and one rotating receiver.
한국 연안의 DGPS 망 구축을 위한 장기갑 기준국으로 부터의 DGPS 측정에 관한 연구
이형욱(Hyeongwook Lee),홍성래(Seongrae Hong),고광섭(Kwangsub Ko),임정빈(Jeongbin Yim),정세모(Semo Jung) 한국항해항만학회 1998 한국항해항만학회 학술대회논문집 Vol.1 No.-
The test transmission of DGPS correction data has been carried out since early 1996. The data has been sent from marine radiobeacon station at Changgi Gap Lighthouse. It was the first test brosdcast of DGPS correction data based on midium frequency of marine radiobeacon where transmission power and rate are 300W and 100bps respectively. However, there has not been any scientific study on the characteristic of the accuracy of a marine DGPS/radiobeacon. Accordingly, this paper investigates the accuracy of the system, which is currently operating in 310KHz. As a result, planned 8 reference station and coverage verified that the differential positioning accuracy using the marine radiobeacon is sufficient to ensure the safety of marine activities around the coast of Korea(position error of distance 107NM at reference station was about 10m(drms)).
변압기 프레스보드 Creepage Discharge와 유중가스 및 퓨란 생성물과의 상관성 분석
손형욱(Hyeongwook Son),김우빈(Woobin Kim),이동준(Dongzoon Lee),김정태(Jeongtae Kim) 대한전기학회 2019 전기학회논문지 Vol.68 No.6
In this study, the analysis for the correlation between the creepage discharge of transformer pressboard and the amount of dissolved gases in the oil and the furanic products has been performed. As a result, it was confirmed that a large and small discharge was concurrently generated until the tracking (carbonization) phenomenon on the pressboard occurred. It is found out that two kinds of process may exist in the correlation between the accumulated partial discharge quantity and the dissolved gas in oil, depending upon discharge pulse magnitude and the generating rate. The ‘fast process’ in which the average discharge pulse magnitude is large and the generating number per second (rate) is big, whereas ‘slow process’ is vice versa. According to the process, the dissolved gas in oil became different. In addition, the generation of CO gas was small during the tracking (carbonization) phenomenon of the pressboard, but there was a correlation with accumulated discharge quantity. On the contrary, CO₂ gas showed no correlation with accumulated discharge quantity. The correlation between the accumulated discharge quantity and the furanic product was very weak, but it is confirmed that 5M2F which is a result of local overheating showed some correlation.
The Effect of Moisture on the Creepage Discharge of Transformer Pressboard
Yoon Sungho,Son Hyeongwook,Kim Woobin,Lee Dongzoon,Kim Jeongtae 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.5
This paper addresses the creepage discharge process in moisture-absorbed pressboard under the AC voltage stress. The measurement for partial discharges, dissolved gases and furan compounds have been performed for various types of specimens such as the normal dry specimen, dry pressboard with much moisture in oil and the wet pressboard. The result showed that partial discharge inception voltage, discharge number and accumulated charge quantity increased and the discharge magnitude per pulse decreased in case of specimen with moisture. The partial discharge patterns at the initial stage in the trend with time showed different according to the types of specimens, but after the initial stage the discharge trend in all cases became similar with recurrence pattern of large/small discharges and then small discharges. In case of dry pressboard with much moisture in oil, the generation of gases was less than compared with normal dry specimen, but a lot of furans generated. On the contrary, in case of wet pressboard, large amount of gas generated almost without furan generation. Results indicated a mechanism of creepage discharge in which moisture aggregated in the amorphous region of the pressboard attracted discharges owing to the electric field enhancement, and the degradation and carbonization of pressboards would be accelerated by these discharges.
오프라인 식별 기반 적응형 ECM 파라미터 기법들의 확장 칼만 필터를 SOC 추정 성능 비교
최연호(Yeonho Choi),박형욱(Hyeongwook Park),이재형(Jaehyung Lee),윤재중(Jaejung Yun) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5
The extended kalman filter based on the battery model is widely used as an SOC estimation algorithm. However, the conventional extended kalman filter uses a single parameter without reflecting the parameters of the ECM that change according to the SOC. However, if the variation of the ECM parameters are not updated, the SOC estimation accuracy is adversely impact. To improve this problem, many research on adaptive ECM parameters have been conducted. In this paper, among the methods, grouping and curve fitting methods for ECM parameters were compared. Using the battery FUDS profile, the SOC estimation performance and algorithm running time of the conventional method and the extended kalman filter to which the adaptive ECM parameters were applied were claculated through simulation.
LTO 배터리 모듈을 위한 BMS 시뮬레이션 모델 개발
손성재(Sungjae Son),이재형(Jaehyung Lee),박형욱(Hyeongwook Park),윤재중(Jaejung Yun) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5
Lithium titanium oxide LTO (Li4Ti5O12) batteries are used in applications requiring high capacity and high output, such as eco-friendly railway vehicle. Until now, simulation models of the BMS(Battery Management System) for Li-ion batteries have been developed. However, no research has been conducted on BMS simulation models for LTO batteries. This paper presents a BMS simulation model for a module with 11 LTO batteries connected in series. It was developed in the MATLAB/SIMULINK environment based on a circuit using ADI’s AFE(Analog Front End) IC and LTO-2717397 battery. In the BMS simulation, the SOC estimation and passive balancing algorithms for a LTO battery module were verified.