• 전기화학회지
• /
• 제21권4호
• /
• pp.68-79
• /
• 2018

최근 늘어나는 배터리 수요를 대처하기 위하여 배터리를 대체하거나 배터리의 구동시간을 늘리기 위한 방법으로 제시되고 있는 에너지 발전소자와 에너지 저장소자의 융합연구는 에너지 관련 기술분야에서 가장 관심받고 있는 분야중 하나이다. 본 리뷰논문에서는 물리에너지 발전소자의 최근 연구동향과 함께 에너지 발전소자와 저장소자의 융합연구 동향을 소개하고자 한다. 먼저, 물리에너지를 전기에너지로 변환하는 압전 특성과 마찰대전 특성을 이용한 에너지 발전소자 관련 연구동향을 소개한다. 또한 압전/마찰대전 에너지 발전소자와 에너지 저장소자의 융합 연구동향을 소개한다. 특히 자가충전 에너지소자의 물리에너지를 전기화학적 에너지로 변환하는 새로운 접근방법을 소개하고자 한다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 추계 학술논문 발표대회
• /
• pp.25-26
• /
• 2018

Various concrete material technologies and new materials have been developed in accordance with the advancement of buildings. As part of these new technologies, light transparent concrete, which was invented by Hungarian architect Aron Losonczi and attracted worldwide attention, has a technique of arranging optical fiber inside concrete and transmitting the light from exterior to concrete to show silhouette inside. However, due to many disadvantages, application to the field was limited and commercialization was not easy. In Korea, Light Emotion Friendly Concrete has been developed for commercialization. In order to solve the degradation of construction performance caused by the arrangement of expensive optical fiber, which is pointed out as a disadvantage of translucent concrete, It converts expensive fiber into low cost acrylic rod, easy to arrange, pre-assembled to form and post-cast. Therefore, this study aims to improve the mechanical properties of LEFC and to derive optimal combination.

• Journal of Electrochemical Science and Technology
• /
• 제9권1호
• /
• pp.20-27
• /
• 2018

We describe a redox-enhanced electric double-layer capacitor (EDLC) that turns the electrolyte in a conventional EDLC into an integral, active component for charge storage-charge is stored both through faradaic reactions with soluble redox-active molecules in the electrolyte, and through the double-layer capacitance in a porous carbon electrode. The mixed-redox electrolyte, composed of vanadium and iodides, was employed to achieve high power density. The electrochemical reaction in a supercapacitor with vanadium and iodide was studied to estimate the charge capacity and energy density of the redox supercapacitor. A redox supercapacitor with a mixed electrolyte composed of 0.75 M NaI and 0.5 M $VOSO_4$ was fabricated and studied. When charged to a potential of 1 V, faradaic charging processes were observed, in addition to the capacitive processes that increased the energy storage capabilities of the supercapacitor. The redox supercapacitor achieved a specific capacity of 13.44 mAh/g and an energy density of 3.81 Wh/kg in a simple Swagelok cell. A control EDLC with 1 M $H_2SO_4$ yielded 7.43 mAh/g and 2.85 Wh/kg. However, the relatively fast self-discharge in the redox-EDLC may be due to the shuttling of the redox couple between the polarized carbon electrodes.

• 세라미스트
• /
• 제22권2호
• /
• pp.122-132
• /
• 2019

Wearable electronic devices with batteries must be lightweight, flexible and highly durable. Most importantly, the battery should be able to self-generate to operate the devices without having to be too frequently charged externally. An eco-friendly energy harvesting technology from various sources, such as solar energy, electromagnetic energy and wind energy, has been developed for a self-charging flexible battery. Although the energy harvesting from such sources are often unstable according to the surrounding environment, the energy harvesting from body movements and vibrations has been less affected by the surrounding environment. In this regard, flexible piezoelectric modules are the most attractive solution for this issue, because they convert mechanical energy to electrical energy and harvest energy from the human body motions. Among the various flexible piezoelectric modules, piezoelectric nanofibers have advantages when used as an energy harvester in wearable devices, due to their simple manufacturing process with good applicability to polymers and ceramics. This review focused on diverse flexible piezoelectric nanofibers and discusses their applications as various energy harvesting systems.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2005년도 ICCAS
• /
• pp.457-462
• /
• 2005

Industrial and economical importance of CP(Cellular Phone) is growing rapidly. Combined with IT technology, CP is currently one of the most attractive technologies for all. However, unless we find a breakthrough to the technology, its growth may slow down soon. RT(Robot Technology) is considered one of the most promising next generation technology. Unlike the industrial robot of the past, today's robots require advanced technologies, such as soft computing, human-friendly interface, interaction technique, speech recognition, object recognition, and many others. In this study, we present a new technological concept named RCP(Robotic Cellular Phone), which combines RT & CP, in the vision of opening a new direction to the advance of CP, IT, and RT all together. RCP consists of 3 sub-modules. They are $RCP^{Mobility}$, $RCP^{Interaction}$, and $RCP^{Interaction}$. $RCP^{Mobility}$ is the main focus of this paper. It is an autonomous navigation system that combines RT mobility with CP. Through $RCP^{Mobility}$, we should be able to provide CP with robotic functionalities such as auto-charging and real-world robotic entertainments. Eventually, CP may become a robotic pet to the human being. $RCP^{Mobility}$ consists of various controllers. Two of the main controllers are trajectory controller and self-localization controller. While Trajectory Controller is responsible for the wheel-based navigation of RCP, Self-Localization Controller provides localization information of the moving RCP. With the coordinate information acquired from RFID-based self-localization controller, Trajectory Controller refines RCP's movement to achieve better RCP navigations. In this paper, a prototype system we developed for $RCP^{Mobility}$ is presented. We describe overall structure of the system and provide experimental results of the RCP navigation.

• 디지털융복합연구
• /
• 제19권12호
• /
• pp.145-150
• /
• 2021

공공장소에서 지속적으로 방역을 수행하기 위해서는 인력확보가 쉽지 않은데 자율주행 기반 로봇을 활용하면 인력으로 인한 문제를 해결할 수 있다. 자율주행 기반 방역로봇은 별도의 인력 투입 없이 공공기관과 병원 등의 유해 바이러스 확산 및 질병을 지속적으로 예방 가능하다. 자율주행 기능은 피나클 필터 알고리즘을 적용하여 위치를 추정하고, 방역은 UV살균시스템 및 이산화염소 분사시스템을 적용하였다. 주행시간은 3시간 이상, 위치 오차는 0.5m.이내, 정지 회피하는 기능은 95%, 장애물 감지 거리는 1.5m에서 동작하였다, 자동충전 복구는 배터리 잔량 10%에서 충전거치대로 이동하여 충전이 되었다. 무인방역시스템으로 방역한 결과 인력배치 없이 UV살균은 99%, 이산화염소는 95% 이상 살균되어 막대한 사회적 비용을 절감하는데 자율주행 방역로봇이 기여할 수 있다.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2016년도 전력전자학술대회 논문집
• /
• pp.255-256
• /
• 2016

This paper is presents a initial starting of SST with high voltage level source. Rush current flowing as difference between capacitor level and grid level can crush the whole system. Thus, industries have used initial constituted by resistance and relay. However the initial circuit used in industries can't apply high voltage application due to isolation and economic feasible problems. Therefore many countries study method can charge capacitor with another voltage sources. Also this paper introduce method charging primary side capacitor efficiently.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2000년도 전력전자학술대회 논문집
• /
• pp.313-316
• /
• 2000

This paper proposes a new solution by carrier-based SVPWM method to solve the most serious problem of Flying Capacitor Multi-level Inverter that is unbalance of capacitor voltages The voltage unbalance is occurred by the difference of each capacitor's charging and discharging time applied to Flying Capacitor Multi-level Inverter. It controls the variation of capacitor voltages into the mean'0' during some period by means of new carriers using the leg voltage redundancy in the Inverter. The solution can be easily expanded to the multi-level. Also this method can make the switching loss and conduction loss of device equal by the use of leg voltage redundancy. First the unbalance of capacitor voltage is analyzed and the conventional theory of self-balance using phase-shifted carrier is reviewed. And then the new method that is suitable to the Flying Capacitor Inverter is explained. The simulation results would be shown to verify the proposed method

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
• /
• pp.87-91
• /
• 2004

In this paper, the paralleled forward converter, that is generally used as the power supply for the low voltage, high current load, is described. The proposed forward converter for battery charging could be provided the power without failure not only in steady state but also in the transient period by the step load variation or the unexpected faults among the converter modules. Each converter nodule designed is operated alone with the self closed controller for the elevation of stability, performance, reliability, and maintainability. The frequency response of the designed converter module is analyzed, and the stability is confirmed in analytic method. And the experiments of the paralleled battery charger are carried out in steady state, in the step load variation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 E
• /
• pp.1816-1818
• /
• 1997

A triggered sparkp gap switch was fabricater and its high-voltage discharge characteristics were studied. The switch is composed of two main electrodes and one trigger electrode which is placed perpendicular to the main one. Spark gap distance was fixed by 25 mm. This device has been operated without self firing at the pulse repetition frequency from 1 to 20 Hz limited by the charging current, and the hold-off voltage from 10 to 30kV. An IGBT switch and igniter coil (originally used in a car) were adopted for a trigger circuit. In this article preliminary switch characteristics of the spark gap switch are reported with the emphasis on the description of the trigger circuit.