A Fully Soft Switched Two Quadrant Bidirectional Soft Switching Converter for Ultra Capacitor Interface Circuits

Amin Mirzaei,Hosein Farzanehfard,Ehsan Adib,Awang Jusoh,Zainal Salam 전력전자학회 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.1

This paper describes a two quadrant bidirectional soft switching converter for ultra capacitor interface circuits. The total efficiency of the energy storage system in terms of size and cost can be increased by a combination of batteries and ultra capacitors. The required system energy is provided by a battery, while an ultra capacitor is used at high load power pulses. The ultra capacitor voltage changes during charge and discharge modes, therefore an interface circuit is required between the ultra capacitor and the battery. This interface circuit must have good efficiency while providing bidirectional power conversion to capture energy from regenerative braking, downhill driving and the protecting ultra capacitor from immediate discharge. In this paper a fully soft switched two quadrant bidirectional soft switching converter for ultra capacitor interface circuits is introduced and the elements of the converter are reduced considerably. In this paper, zero voltage transient (ZVT) and zero current transient (ZCT) techniques are applied to increase efficiency. The proposed converter acts as a ZCT Buck to charge the ultra capacitor. On the other hand, it acts as a ZVT Boost to discharge the ultra capacitor. A laboratory prototype converter is designed and realized for hybrid vehicle applications. The experimental results presented confirm the theoretical and simulation results.

A Fully Soft Switched Two Quadrant Bidirectional Soft Switching Converter for Ultra Capacitor Interface Circuits

Mirzaei, Amin,Farzanehfard, Hosein,Adib, Ehsan,Jusoh, Awang,Salam, Zainal The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.1

This paper describes a two quadrant bidirectional soft switching converter for ultra capacitor interface circuits. The total efficiency of the energy storage system in terms of size and cost can be increased by a combination of batteries and ultra capacitors. The required system energy is provided by a battery, while an ultra capacitor is used at high load power pulses. The ultra capacitor voltage changes during charge and discharge modes, therefore an interface circuit is required between the ultra capacitor and the battery. This interface circuit must have good efficiency while providing bidirectional power conversion to capture energy from regenerative braking, downhill driving and the protecting ultra capacitor from immediate discharge. In this paper a fully soft switched two quadrant bidirectional soft switching converter for ultra capacitor interface circuits is introduced and the elements of the converter are reduced considerably. In this paper, zero voltage transient (ZVT) and zero current transient (ZCT) techniques are applied to increase efficiency. The proposed converter acts as a ZCT Buck to charge the ultra capacitor. On the other hand, it acts as a ZVT Boost to discharge the ultra capacitor. A laboratory prototype converter is designed and realized for hybrid vehicle applications. The experimental results presented confirm the theoretical and simulation results.

울트라 커패시터를 이용한 연료전지 하이브리드 차량의 성능 시뮬레이터 개발

국광표(Kwangpyo Kook),오경철(Kyungcheol Oh),김현수(Hyunsoo Kim) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

In this paper, performance simulator is developed for fuel cell hybrid electric vehicle(FCHEV) using ultra-capacitor. Dynamic models of powertrain components such as fuel cell stack, ultra-capacitor, traction motor, DC/DC converter, etc. are obtained by modular modeling using MATLAB SIMULINK. Using the simulator, hydrogen fuel economy and performance of FCHEV are evaluated for different energy storage device(Battery and Ultra-capacitor). Simulations are carried out for the power assist algorithm. It is found from the simulation results that using ultra-capacitor provides better performance especially in the braking energy recuperation and assist power than using battery.

친환경 Ultra-capacitor에 의한 순시전압강하의 직렬전압보상 시스템

손진근(Jin-Geun Shon),전희종(Hee-Jong Jeon) 대한전기학회 2009 전기학회논문지 Vol.58 No.4

A series voltage compensation(SVC) system is a power-electronics controller that can protect sensitive loads from disturbance in the supply system. Especially, voltage sags are considered the dominant disturbances affecting the power quality. This paper dealt with a system of off-line type voltage sag compensation by using a bi-directional DC/DC converter of environmentally friendly ultra-capacitor. This capacitor is attached to the DC link of SVC through the high-efficiency DC/DC converter in order to compensate the DC link voltage drop during short-term power interruption as voltage sags. Therefore, in this paper, a DC/DC converter to control high-efficiency energy of ultra-capacitor and voltage sag detection algorithm of off-line type SVC systems are newly introduced. According to the results of experimental of prototype system, it is verified that the proposed system has effectiveness of voltage sag compensation using an ultra-capacitor.

하이브리드 차량 시뮬레이터에서의 배터리와 초고용량커패시터 모델 성능 평가

전형준(Hyungjun Jeon),장재훈(Jaehoon Jang),유지윤(Jiyoon Yoo) 한국자동차공학회 2008 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

This paper suggests the simulation models of the battery/ultra capacitor in HEV simulator and evaluates them. Getting the impedances of the battery/ultra capacitor for composing of the simulation block of the battery/ultra capacitor in HEV simulator and finding the homologous point between voltage and SOC for predicting how much energy is left in the battery/ultra capacitor. Those are considered in this paper by using frequency response, transfer function method and charge and discharge curve tor making the simulator.

가속 수명 시험을 활용한 전기식 하이브리드 굴삭기용 Ultra-capacitor 수명 추정

김광운(Kwangwoon Kim),임정우(Jeongwoo Lim) 한국자동차공학회 2015 한국자동차공학회 학술대회 및 전시회 Vol.2015 No.11

본 논문에서는 하이브리드 굴삭기의 회생 에너지 저장 장치인 Ultra-capacitor 에 대하여 가속 수명 시험을 설계하고 검증하였으며, 필드 수명을 예측하였다. 우선 사전 수명 자료 및 고장 모드를 분석하여 셀의 성능 열화(정전 용량 감소)를 가장 중요한 고장으로 선정하고 전압-온도 가속 수명 모델을 수립하였다. 또한, 필드 조건과 최대한 유사한 부하 사이클로 가속 수명 시험을 할 수 있도록 전력 부하 사이클 모사가 가능한 시스템 Rig 장치를 고안하여 평가하였다. 시험 시료는 셀 용량과 직렬 개수가 다른 2 종류의 모듈에 대하여 순차적으로 수행하였는데, 1 차 시험에서는 Ultra-capacitor 모듈의 시간에 따른 용량 변화(열화에 의한 감소) 곡선을 Capacitance 추정에 의해 획득하였고, 초기 치의 70%까지의 용량 감소를 수명 판단 기준으로 했을 때 목표 수명인 B10 10,000 h(신뢰수준 60%)을 만족함을 확인하였다. 또한 같은 가속 모델을 이용하여 Cost 절감형 저 ESR 모듈에 대한 2 차 시험을 실시하였는데, 목표 수명인 B5 8,600h(신뢰수준 60%)를 만족하였고 용량 감소 추이를 볼 때 잔존 수명이 추가로 남아 있음을 확인하였다. 본 논문에서 제시한 UC 가속수명모델과 지속적인 수명 자료 확보를 통해 향후 개발되는 모듈에 대하여 필드 수명을 보다 정확하게 추정할 수 있을 것으로 기대된다.

차세대 산화막용 초박막 SiO2의 특성 평가

정상현(Sang-Hyun JEONG),김용성(Yong-Seong KIM),김재현(Jae-Hyun KIM),김지형(Ji-Hyung KIM),김광호(Kwang-Ho KIM),김영남(Yeong-Nam KIM) 한국정보기술학회 2005 Proceedings of KIIT Conference Vol.2005 No.-

급속 건식 열산화를 이용하여 850~1050 ℃의 온도범위로 초박막 SiO2를 p-Si(100) 위에 성장시켰다. 초박막 산화막의 유전상수는 게이트 전극의 면적과 측정된 커패시턴스로 산출하였다. 초박막 산화막 두께는 ellipsometer와 10 ㎑ C-V특성에서 Maserjian이 제안하는 방법에 따라 평가하였으며 MOS 커패시터에서 측정된 산화막 두께는 33.6Å이었다. 산화막에 대한 전기적 특성을 평가하기 위해 정전용량-전압, 전류-전압 특성을 이용하였으며, C-V 특성에서 산출된 초박막 산화막 두께가 111.6Å인 MOS 커패시터 midgap 부근에서의 최소 계면 준위 밀도는 6~10×1010 /㎝2eV 였다. In this paper, ultra-thin silicon dioxides were grown on p-type(100) oriented silicon employing rapid thermal dry oxidation technique at the temperature range of 850~1050 ℃. Dielectric constant of ultra-thin SiO2 is estimated by the capacitance following the variable area of gate electrode. The 10 ㎑ C-V characteristics are used to estimate the thickness of the ultra-thin oxides following the method proposed by Maserjian, The estimated oxide thickness in this MOS capacitor was about 33.6 Å. The capacitance-voltage, current-voltage characteristics were used to study the electrical properties of these thin oxides. The minimum interface state density around the midgap of the MOS capacitor having oxide thickness of 111.6 Å derived from the C-V curve was ranged from 6 to 10×1010 /㎝2eV.

700 F hybrid capacitors cells composed of activated carbon and Li₄Ti₅O₁₂ microspheres with ultra-long cycle life

Ruan, Dianbo,Kim, Myeong-Seong,Yang, Bin,Qin, Jun,Kim, Kwang-Bum,Lee, Sang-Hyun,Liu, Qiuxiang,Tan, Lei,Qiao, Zhijun Elsevier Sequoia 2017 Journal of Power Sources Vol. No.

<P><B>Abstract</B></P> <P>To address the large-scale application demands of high energy density, high power density, and long cycle lifetime, 700-F hybrid capacitor pouch cells have been prepared, comprising ∼240-μm-thick activated carbon cathodes, and ∼60-μm-thick Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> anodes. Microspherical Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> (M-LTO) synthesized by spray-drying features 200–400 nm primary particles and interconnected nanopore structures. M-LTO half-cells exhibits high specific capacities (175 mAhh g<SUP>−1</SUP>), good rate capabilities (148 mAhh g<SUP>−1</SUP> at 20 C), and ultra-long cycling stabilities (90% specific capacity retention after 10,000 cycles). In addition, the obtained hybrid capacitors comprising activated carbon (AC) and M-LTO shows excellent cell performances, achieving a maximum energy density of 51.65 Wh kg<SUP>−1</SUP>, a maximum power density of 2466 W kg<SUP>−1</SUP>, and ∼92% capacitance retention after 10,000 cycles, thus meeting the demands for large-scale applications such as trolleybuses.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Assembly of 700 F AC/M-LTO hybrid capacitor pouch cells. </LI> <LI> AC and LTO electrodes with high density and high mass loading. </LI> <LI> Hybrid capacitor with high energy density, high power density, and long cyclability. </LI> </UL> </P>

직렬형 HEV의 엔진/발전기, 배터리, 울트라캐패시터 파워분배전략

정유석(Yuseuk Jung),김현섭(Hyunsup Kim),고영관(Youngkwan Ko),정순규(Soonjyu Jeong),최현석(Hyunseok Choi),이윤복(Yoonbok Lee),이형철(Hyeongcheol Lee) 한국자동차공학회 2010 한국자동차공학회 부문종합 학술대회 Vol.2010 No.5

This paper is concerned with a supervisory control strategy for a series hybrid electric vehicle (SHEV). The powertrain of the SHEV consists of an engine/generator and an electrical storage system (ESS) in which not only a battery but also an ultra-capacitor is incorporated. There is a detailed configuration that the ultra-capacitor is connected to a bi-directional dc-dc converter for being controlled actively whereas the battery is directly tied to the electric floating bus. In order to achieve several objectives such as extending battery life by slowing battery current level variation strategy among a engine, a battery and a ultra-capacitor based on a power follower control plus frequency distribution strategy. A signal processing technique is introduced for the decomposition of the electrical power demand into command signals to control engine power and ultra-capacitor power while the battery responds autonomously to the residue of power demand. A forward simulation model is built in Cruise® and MATLAB/Simulink®. The Simulation results verify the effectiveness of the proposed sstrategy.

PRT 차량의 전력 공급시스템 개발

김백현(Baek-Hyun Kim),정락교(Rag-Gyo Jeong),정상기(Sang-Gi Chung),강석원(Seok-Won Kang) 대한전기학회 2013 전기학회논문지 Vol.62 No.2

In this paper, the design of PRT vehicle power supply system is discussed. Since there is no power feeding line facilities in PRT system under development, the PRT vehicle must have its own energy storage device on board. For the energy storage device, ultra-capacitor bank is applied due to its fast charging capability and long life time. Charging the Ultra-capacitor bank is performed by wireless inductive power transfer system. The capacitor bank is charged up in less than 10 seconds when the vehicle is traveling by passenger stations. In this paper the design of the ultra-capacitor bank and the wireless inductive power transfer system for the PRT vehicle are discussed. Tests are conducted for the both system and the result shows the efficiency of the wireless inductive power transfer system is higher than 80%.