전기자동차용 EDLC축전시스템의 제어 알고리즘 연구

한운동 忠州大學校 2012 한국교통대학교 논문집 Vol.47 No.-

Recently, in energy storage system, the EDLC is paid attention as a new environmentally friendly energy storage element. This capacitor has higher energy density than the electrolytic capacitor. Also, this capacitor has a lot of advantage such as no maintenance, longer life cycle and faster charge-discharge time than the battery system. But the EDLC must have a each charge-discharge controller to control high effective, a direct-parallel switching circuit to effectively use energy, and several compensation techniques to control a optimal operating.

동적전압보상시스템에서 LC필터 전압궤환의 제어특성 비교

한운동 한국교통대학교 2015 한국교통대학교 논문집 Vol.50 No.-

Dynamic voltage restorers(DVRs) are mainly used to protect sensitive loads from the electrical network voltage disturbances such as sags or swells and could be used to reduce harmonic distortion of ac voltages. The typical DVR topology essentially contains a voltage source inverter (VSI) with LC Filter, an injection transformer connected between the ac voltage line and the sensitive load, and a DC energy storage device. For injecting series voltage, the PWM inverter is used and the low pass filter consist of inductor(L) and capacitor(C) eliminates the harmonics of the PWM voltage of the inverter. However there are voltage pulsation responses by the characteristic of the LC lowpass filter that eliminate the harmonics of the PWM output waveform of the inverter. Therefore, this paper compared control and frequency response characteristic of LC filter voltage feedback with the DVRs. The voltage control by LC filter should be connected in the line side since this feedback method allows a relatively faster dynamic response, enabling the elimination of voltage notches or spikes in the beginning and in the end of sags and strong load voltage THD reduction.

최근 10년간 발생한 신손상 분석

최동은, 김원태, 김용준, 윤석중, 이상철, 김원재 충북대학교 의과대학 충북대학교 의학연구소 2012 忠北醫大學術誌 Vol.22 No.1

연구목적: 신손상은 보통 복부외상 환자의 10% 정도에서 발생하며 비뇨기계에서 발생하는 손상 중 가장 높은 빈도를 차지하고 있다. 신손상 치료의 궁극적인 목표가 환자의 생명을 구하는 것이고, 가능 하면 신조직을 최대한 보존하면서도 합병증은 최소화하여야 하므로 정확하게 평가된 진단을 내려, 혈류 역학적으로 안정된 경우 보존적 요법을 시행하는 빈도는 증가하고 있다. 본 연구에서는 10년간의 신손 상을 분석하여 손상의 원인, 정도, 치료 방법 등을 알아보고자 하였다. 대상및방법: 2000년 2월부터 2010년 6월까지 본원 응급실에 방문하여 신손상으로 진단된 59명의 환 자들을 후향적으로 분석하였다. 결과: 환자의 성별은 남자가 39례 (66.1%)였고, 여자가 20례 (33.9%)였다. 신손상의 원인은 교통 사고가 37례 (62.7%)였고, 낙상이 7례 (11.9%), 외상이 12례 (20.3%), 자상이 1례 (1.7%), 원 인미상이 2례 (3.4% )였다. 손상의 정도는 I 등급이 11례 (18.6%), II 등급이 10례 (16.9%), III 등급이 20례 (33.9%), IV 등급이 10례 (16.9%), V 등급이 8례 (13.6%)였다. 신손상 환자의 치료 는 대증치료가 46례 (77.9%)였고, 신절제술이 5례 (8.5%), 신혈관색전술이 5례 (8,5%), 그외 다른 치료들이 3례 (5.1%)였다. 결론: 신손상의 원인은 교통사고와 외상 등이 가장 많은 비중을 차지했으며, 3 등급의 손상이 가장 많 았고, 치료는 대증요법이 주를 이루었지만, 점차 신혈관색전술이 늘어나고 있다. 앞으로 지역단위로의 추가적인 연구가 필요할 것으로 생각된다.

3상 정류기의 고조파 경감을 위한 스위칭 회로에 관한 연구

한운동 韓國交通大學校 2013 한국교통대학교 논문집 Vol.48 No.-

In this paper, a new control circuit for shaping the line current and reducing the total harmonics distortion in three phase diode rectifier is presented. In the past years, three phase diode rectifier have been used widely. Because a three-phase diode rectifier don't need controller, it's a cheap and reliable method to get DC voltage. However an harmonics problems which make an acoustic noise, overheat, a disorder of computer system and sometimes mess a communication system are caused. In an uncontrolled diode rectifier, current is drawn from the ac mains only during the period in the ac cycle when the instantaneous voltage is greater than the voltage across the dc-link capacitor. As a result, current is of pulsed nature with the amplitude dependent on the size of the capacitor. a pulsed natured current is so discontinuous that it makes a harmonics problems. In this study, the three bidirectional switches rated at very small power are installed in a conventional three phase diode rectifier. Using those switches, an idle current charges to capacitors continuously. Simulation's and Experimental's results demonstrate a reduction of harmonics, a improvement of power factor and THD.

電力品質 補償裝置인 DVR의 瞬間電壓降下 檢出에 關한 硏究

한운동 忠州大學校 2007 한국교통대학교 논문집 Vol.42 No.-

The recent growth in the use of impactive and nonlinear loads, electronic, and medical devices sensitive to power quality has caused many power quality problems and power supply-and-demand problem. Recently, in power system, not only the reliability of the power supply but also the DVR(Dynamic Voltage Restorer), UPS, and APF are being studied more and more. Hence, in this paper, Voltage sag detection algorithm for voltage sag corrector is proposed. Also, simple circuit for the experimental voltage sag is introduced.

CPLD를 利用한 電力變換用 專用칩 開發에 關한 硏究

韓運東,林炳國 충주대 2001 한국교통대학교 논문집 Vol.35 No.2

The use of HDL(Hardware Description Language) is now central to the ASIC(Application Specific Integrated Circuit).HDL-based ASIC can simplify the process of development and has a competition in market because it reduce the consuming time for the design of IC(Integrated circuit) in system level.Therefore, the development of power electronics system on chip (SOC), to design microcontroller and switching logic as one chip, is required extremely for the purpose of having reliability and low cost in power electronics which is based on switching elements.The major application of SOC is variable converter, active filter, inverter for induction motor, UPS and power supply with a view to reducing electromagnetic pollution.

Solid-static Switching device를 使用한 電力 品質改善에 關한 硏究

韓運東 충주대 산업과학기술연구소 2001 産業科學論文集 Vol.9 No.-

Utility distribution networks, sensitive industrial loads, and critical commercial operations all suffer from various types of outages and service interruptions which can cost significant financial loss per incident based on process down-time, lost production, idle work forces, and other factors. The types of interruption which are experienced can generally be classified as power quality related problems caused by voltage sag and swells, lightning strikes, and other distribution system related disturbances. In many instances, the use of a Solid-State Transfer Switch(SSTS) and or a Distribution Level Static Compensator(D-STATCOM) can be som of the most cost-effective solutions for these types of power quality problems. The SSTS, which essentially consists of a pair of thyristor switch devices, enables seamless transfer of energy from a primary source to an alternate source in order to avoid service interruption upon a deficiency in power quality. The D-STATCOM, which consists of a thyristor-based voltage source inverter, uses advanced power electronics to provide voltage stabilization, flicker suppression, power factor correction, harmonic control, and a host of other power quality solutions for both utility and industrial applications.

SPICE Simulation을 利用한 UPS의 設計와 應用에 關한 硏究

韓運東 충주대 산업과학기술연구소 1999 産業科學論文集 Vol.7 No.1

In this paper the well known simulation software package PSPICE "Electrical Circuit Simulation" is used to simulate the performance of an on-line UPS system under steady state and transient operation conditions. The steady state operation of the UPS system includes its normal as well as its standby operation. The transient operation is simulated for different cases, namely, transient from normal to standby condition and vice-versa, in the normal supply, the application of a sudden short circuit in some battery cells, and the application of a sudden load or short circuiting the load.

DVR用 인버터 필터의 設計 및 分析

한운동 충주대학교 2006 한국교통대학교 논문집 Vol.41 No.-

The role of the inverter-side filter used in the dynamic voltage restorer (DVR) is examined. Using circuit analysis method, it is shown that the selection of the filter parameters can affect the DVR inverter rating. Furthermore, with the DVR filter-series injection transformer combination, the loading effect of the filter on the restorer and the primary supply system has been quantified under normal as well as voltage sag conditions. A systematic filter design method is then proposed, the primary objective of which is to achieve specific harmonic performance while ensuring that the DVR inverter rating and the loading effect are minimized. Illustrative examples are also included.

特定高調波 除去方式에 依한 交流 制御用 Inverter 硏究

韓運東,池平植 충주대 2004 産業科學論文集 Vol.12 No.-

In electrical industry, development of inverter technique make to control AC motor precisely. So the using inverter spreads fast. The motor using inverter has high efficiency, characteristic of constant torque, output and etc. However, in spite of many good things of using inverter, VS-Motor is used widely because of simple control and cheap cost. VS-Motor is speed control method using eddy-current coupling. This method installs eddy-current coupling with constant speed driving induction motor and controls rotating speed through a charging change of a excitation current, particularly. But this method has large losses and low efficiency because of heating as slip drum in low speed region. In cooling, addition of a mechanical devices is difficult and in volume, large space is occupied. Using SCR for control, efficiency of system is low. In case of inverter, though advantage of high efficiency and high performance the price is expensive. Therefore, in this study, we developed VVVF Inverter system for controlling AC power. A using micro-controller can make the price down and it has many devices so it can be expected the system's compact and low noise effect.