• Journal of Power Electronics
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• v.12 no.1
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• pp.223-231
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• 2012

In this paper, criteria for better selection of a supercapacitor through EIS (Electrochemical Impedance Spectroscopy) experiments are presented. The performance characteristics of a supercapacitor are thoroughly analyzed in terms of losses and available energy to select the optimal product. The validity of the proposed criteria is demonstrated through the computer simulations and experiments on a fuel cell vehicle using a supercapacitor module with the FTP-72 urban dynamometer driving schedule.

• Journal of Power Electronics
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• v.14 no.1
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• pp.1-10
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• 2014

This paper proposes a high-efficiency supercapacitor charger. Conventional two-switch forward converter can be used for charging supercapacitors. However, the efficiency of conventional converters is low because of their switching losses. This study presents a high-efficiency two-switch forward converter for supercapacitor chargers. The proposed converter improves power efficiency by 4 %, from 89 % to 93 %. The proposed converter has the advantages of reduced switch voltage stresses and minimized circulating current when compared to other converter topologies. The performance of the proposed converter is evaluated by experimental results using a 300 W prototype circuit for a 54-V, 35-F supercapacitor bank.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.1
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• pp.65-69
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• 2010

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. And, social demand on fuel economy and reducing pollution needs equipment of new function such as energy storage system with good power performance, high cyclability and good energy efficiency. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the fundamental characteristics of supercapacitor unit and charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.8 s.251
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• pp.756-763
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• 2006

PEMFC has several technical problems such as water management, long term stability and performance degradation as. PEMFC has been studied not only to solve water management, but also to generate power in stable manner to system by using a hybrid system with auxiliary energy storage device. The purpose of this study is to couple PEMFC with supercapacitor to make a hybrid system and to design and test control strategies for stable power generation in case of changing output power. The polarization curve and dynamic behaviors while changing power were investigated to find out characteristics of PEMFC stack. A DC/DC converter was fabricated in order to increase fuel cell and supercapacitor voltage and to charge supercapacitor. We found that the operation strategy 2 was recommended to the system because of solving water management problem and increasing the dynamic behavior.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.11
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• pp.84-93
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• 2009

In this paper, we propose to study the possibility of using a photovoltaic system combined with a high speed micro-turbine. This hybrid system can work as stand-alone system or grid connected system as it will be a part of a micro-grid. Initially, we propose Matlab/Simulink dynamic models of photovoltaic, micro turbine systems and supercapacitor. Then, we carry out a simulation comparison of the two systems, this is, with supercapacitor and without supercapacitor bank. We show that supercapacitor bank as short-term storage device was necessary to reduce the fast fluctuation of power in the case of sensitive loads. It is verified the simulation results of Matlab/Simulink based hybrid power system represent the effectiveness of the suggested hybrid power system.

• Journal of Power Electronics
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• v.19 no.1
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• pp.316-331
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• 2019

A practical application of a supercapacitor energy storage system in a polarization instrument is proposed on the basis of the energy storage requirements of an induced polarization (IP) transmitter for geophysical exploration. We focused on the energy storage system of a supercapacitor, the topology of the power converter, and the system control strategy as key technologies, and we performed theoretical research and experimental tests on the system and developed an experimental platform. The experiments validated the theoretical research on the key technologies of the supercapacitor energy storage system and demonstrated the effectiveness of the innovation. Results showed that the storage system is efficient and satisfies the energy storage needs of the IP transmitter.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.136-139
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• 2021

In this paper, we studied the charging characteristics of high-capacity supercapacitor with high current for RF wireless charging system for smart phone charging. The dc output of the RF-DC receiver is connected to supercapacitor after which is connected to DC-DC converter for charging a smart phone. This configuration stably supplies voltage and current for charging it. Studies show that the higher charging current use, the rapidly shorter the charging time of supercapacitor is. The currents of 2A, 10A and 27A were used for charging supercapacitors. The charging time was measured for 3000F, 6000F, 12000F supercapacitors which is parallelly connected with 3000F supercapacitors.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.05b
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• pp.124-127
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• 2000

The purpose of this study is to research and develop PAn-Carbon composite electrode for Supercapacitor. Supercapacitor cell of PAn-Carbon composite electrode with 1M $LiClO_{4}/IPC$ brings out good capacitor performance below 4.0V. The radius of semicircle of PAn-Carbon composite electrode adding 30wt% Acetylene Black was absolutely small. The total resistance of Supercapacitor cell mainly depended on internal resistance of he electrode. The discharge capacitance of PAn-Carbon on composite with 30wt% Acetylene Black in 1st and 50th cycles was 29 and 31F/g at current density of $1mA/cm^2$. The capacitance of PAn-Carbon composite with 30wt% Acetylene Black capacitor was larger than that of PAn capacitor without Acetylene Black. The coulombic efficiency of supercapacitor at discharge process of 1 and 50 cycles were 94 and 100%. respectively. PAn-Carbon composite Supercapacitor with 30wt.% Acetylene Black content showed good capacitance and stability with cycling.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.4
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• pp.617-621
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• 2016

In addition to the energy storage facilities based on high power technologies, Electric double layer capacitors(EDLC) are today's candidate for power quality stabilization. However, its low energy density is often inhibiting factor for application of electric power industry. Hybrid supercapacitor is an promising energy storage device that positioned between conventional EDLC and Li-ion battery. This paper describes the preparation and characteristics of a hybrid supercapacitor and module for power quality stabilization. A cylindrical 3200F hybrid supercapacitor ($60{\times}74.5mm$) was assembled by using the $Li_4Ti_5O_{12}$ electrode as an anode and activated carbon as a cathode. It shows 2.5 times higher energy density than conventional EDLC with the same volume. In order to determine the characteristics of the hybrid supercapacitor Module for uninterruptible power supply (UPS), hybrid supercapacitor cells were connected in series with active balancing circuit. At even the high current density of 14A(10C), Module prepared by 18 cells showed the capacitance of 170F at 30~50V, suggesting the applicability for UPS.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.54 no.11
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• pp.561-568
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• 2005

This paper proposes a method that distributes the load power and stores the regenerated energy for a hoist-load system using the supercapacitor, an energy storage device. The crane, which is a representative hoist-load system, operates in two modes. The first is the hoist-up mode in which the load container is lifted up: the maximum power is required at the end of acceleration. The second is the hoist-down mode in which the load container is lifted down; the regenerated energy is wasted by the resistor In this paper, the supercapacitor stores the regenerated energy in the hoist-down operation and supplies the peak power demand in the hoist-up operation. The same structure as the commercially available three-phase inverter is proposed as a bidirectional do-dc converter to charge and discharge the supercapacitor. A power control algorithm is proposed to optimize the load sharing between the generator and the supercapacitor. Using the proposed method, it is effected that the generator size can be cut down to one third of the original one; it leads to the reduction of the fuel consumption, noise and air pollution. Simulation and experimental results verify the effectiveness of the Proposed method.