• Proceedings of the KIEE Conference
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• 2007.04c
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• pp.215-217
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• 2007

This paper proposes the method to improve the charging speed of high voltage capacitor used in the portable medical device. The feedback control method with microprocessor was used to detect charging time and control charging voltage. The result shows that the proposed method is more efficient than only voltage check method with typical charging sequence control.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.2
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• pp.149-156
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• 2014

This paper proposes the battery charging algorithm for small-scale wind power generator using three phase PWM converter. it is impossible to control output power of the converter in over wind speed region since back EMF of PMSG is higer than battery voltage. Therefore, battery charging algorithm is proposed to expand battery charging over wind speed region. The suggested method is using the q-axis current for battery charging in the rated wind speed region. In the over wind speed region after it lower back EMF of PMSG using d-axis current it can control output power of the converter. The validity of the proposed algorithm are verified by experiments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.4
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• pp.484-489
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• 2014

Three phase PWM(Pulse Width Modulation) converter of the small-scale wind power system is able to charge battery under the rated wind speed regions. However, it is impossible to control output power of converter at the over win speed region because back-EMF(Electro Motive Force) of PMSG(Permanent Magnet Synchronous Generator) is higher than the battery terminal voltage of PMSG is reduced. However, the cut-off wind speed exists although battery charging algorithm is implemented by flux weakening control method. Therefore, this paper performs analysis of other factors which affects limitation wind speed. The validity of the analysis are verified through simulation.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.548-551
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• 2000

The battery charger for high speed trail car is very important power source for the purpose of safty and system stability. it provides control power of VVVF, CVCF, DC/DC converter and inverter for traction motor. This paper included power circuit of the ZVZCS type battery charger for high speed trail car and battery included power circuit of the ZVZCS type battery charger for high speed trail car and inverter for traction motor. This paper included power circuit of the ZVZCS type battery charger for high speed trail car an battery charging algorithm. Also the optimum parallel operation of 50Kw battery charger for high speed trail car and charging control method of Ni-Cd battery illustrates validity and effectiveness through the experiments.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.70-71
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• 2014

In this paper, an advanced charging strategy for improving the charging performance of the Li-ion polymer battery is proposed, which is based on the battery characteristic. Simulation results show that the proposed charging current pattern can improve the charging speed of battery in comparison with the standard CC-CV (constant current - constant voltage) charging strategy and the pulse-charging strategy.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.77-84
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• 2002

For the purpose of obtaining a fundamental data which is needed to develope the port injection type charged LPLi engine system, we manufactured intake port injection system of liquid charging LPG and modified heavy duty single cylinder LPLi engine from heavy duty diesel engine. Engine output and emission characteristics were analyzed under variable air/fuel ratio and charging pressure. Since LPG is consisted of propane and butane, we investigated combustion characteristics using this two kinds of fuel. From the result of charging engine performance test, engine torque increase about 30% ∼ 40% with 0.3bar charging pressure. In low speed condition, as charging pressure increase, combustion stability improve ill lean bum condition, but, in high speed condition, combustion stability make worse in lean bum condition. We know that engine output decreased rapidly from the condition of air excess ratio 1.3. In addition, we measured emission characteristics under the lean bum and charging condition. From this experiment, we found that CO emission is out of the question in the range from stiochiometric to lean burn and charging condition, but charging pressure has influence on HC emission.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1146-1148
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• 2007

This paper proposes a method to improve the charging speed and discharging performance of a high voltage capacitor used in a portable medical device. The improvement of the charging speed was achieved by duty cycle control. The discharging performance was carried out by varying the phase duration and the leading edge voltage of the output according to the transthoracic impdedance of the patient. As a result, the improvement in the charging speed and the performance of the discharging parameters shorten the patient treatment time.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.197-199
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• 2006

This paper proposes the method to improve the charging speed of high voltage capacitor used in the medical device with high voltage. Feedback control method with microprocessor was used to detect and control the charging voltage. The result shows that the proposed method is more efficient than the previous converting method with typical PWM IC.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.353-358
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• 2001

Turbo-charging or Super-charging has been used to boost engine power for Gasoline Engine and Diesel Engine came to the world at the beginning of $20^{th}$ century. So far Turbo-Charger has enjoyed a high reputation in the charging filed for its technical advantages such as no demand of operation power from engine and an excellent charging effect in the event of a static operation at mid- and high engine speed. A mechanically driven Super-Charger, however, is now emerging in order to meet demands of the age of speed such as high engine power for a quick change of the driving mode - high engine torque even at low engine speed. Since Super-Charger needs driving power from engine, it cannot improve its relatively higher fuel consumption against that of Turbo-Charger. This negative point is still an obstacle to the wide use of Super-Charger. Super-Charger using Screw-type compressor which has already had a considerable base in air compressor market will fulfill this purpose of improving fuel consumption by minimizing operation power owing to no charging at idling or partially loading driving. This study aims to develop power control concept to achieve this minimization of operation power.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.2
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• pp.141-145
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• 2017

This paper presents a method to improve Li-ion battery charging speed for portable electronic devices maintaining stable operating temperature. The proposed method uses multiple chargers which consist of a master module and slave modules designed with single wire communication signal for parallel current path in order to simplify the additional hardware needs. A single wire communication signal control between a master module and slave modules makes the number of pins of parts lowered and the required area small, furthermore leading to lower cost. Therefore the proposed charging method can be practically used for implementing battery charging modules requiring high speed Li-ion battery charging.