• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.557-562
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• 2009

Recently, researchers are developing a new, clean, renewable and sustainable energy to the industrial areas and the residential areas. Solar cell and fuel cell energy are presented in this paper. The paper shows the P-I and I-V characteristics of fuel cells which are connected in parallel and series. And the voltage drop of internal resistance of the fuel cell decreases with the increasing of the current of the fuel cell. A voltage drop at the internal resistance is increased according to the current, thus the terminal voltage is decreased. The internal resistance is calculated $0.3[\Omega]$ from maximum power transfer condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.9-9
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• 2010

The proton exchange membrane fuel cell (PEMFC) holds great promise of clean power. However, in practical applications which use the PEMFC as the power source, the output voltage from the fuel cell undergoes transient response especially during acceleration and deceleration. This paper presents the relationships between the internal voltage drop, voltage of time constant, time constant of FC1 and FC2 (in series and in parallel) charge curves and discharge curves respectively.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.10
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• pp.1835-1839
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• 2008

Power management is a very important issue in portable electronic applications. Portable electronic devices require very efficient power management like LDO to increase the battery life. As the voltage variation of battery power is large in the application of cell phone, camera, laptop, automotive, industry application and so on, battery power is not directly used and LDO is used to supply the power of internal circuit. Besides, LDO can supply DC voltage that is lower than bauer voltage and constant DC voltage that is not related to largely fluctuated battery power. In the study, the power-save mode current and IR-drop characteristics are analyzed from a LDO with on-chip fabricated in 0.18-um CMOS technology.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1248-1250
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• 2002

AC AT feeding system is possible to do the long distance feeding due to compensate the voltage drop. Nowaday this is a typical and efficient type all over the world in high speed train and heavy transport capacity. Normally a Auto-transformer is installed at regular internal (5 to 10km) between Substation and Sectioning post, this study is reviewed the voltage drop according to train movement and the optimal location of auto transformer, and provided the efficient feeding configuration.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.7
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• pp.530-533
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• 2010

The proton exchange membrane fuel cell (PEMFC) holds great promise of clean power. However, in practical applications which use the PEMFC as the power source, the output voltage from the fuel cell undergoes a transient response especially during acceleration and deceleration. This paper presents the relationships between the charge curves of the internal voltage rise, discharge curves of the internal voltage drop, the voltage with a time constant $V_{\tau}$ and finally, the load and time constant $\tau$ of $FC_1$ and $FC_2$, connected both in series and in parallel.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.493-497
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• 2000

A battery is the device that transforms the chemical energy into the direct-current electrical energy without a mechanical process. Unit cells are connected in series to obtain the required voltage while being connected in parallel to organize capacity for load current. Because the voltage drop down in one set of battery is faster than in two one it may result in the low efficiency of power converter with the voltage drop and cause the system shutdown. However when the system being shutdown. However when the system being driven in parallel a circular-current can be generated,. It is shown that as a result the new batteries are heated by over-charge and over-discharge and the over charge current increases rust of the positive grid and consequently shortens the lifetime of the new batteries. The difference between the new batteries and old ones is the amount of internal resistance. In this paper we can detect the unbalance current using the microprocessor and achieve the balance current by adjusting resistance of each set, The internal resistance of each set becomes constant and the current of charge and discharge comes to be balanced by inserting the external resistance into the system and calculating the change of internal resistance.

• Journal of Hydrogen and New Energy
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• v.3 no.2
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• pp.63-69
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• 1992

Two unit cells were made and operated with oxygen and air as oxidants After 350 hours operation with oxygen, the open circuit voltage drop of unit cell was 30 mV and internal resistance increased. After 250 hours operation with air, the open circuit voltage drop was 130mV. And the open circuit voltage difference of two cases was 90mV. In order to improve the performance of the unit cell with air, the supplying method of the electrolyte and the mass transfer characteristics of the electrode should be studied.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1242-1244
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• 1993

As increasing of internal resistance value at MCFC electrode, out voltage of battery is decreased currently. We measured overpotential and IR drop which consist of resistance factors in MCFC electrode, and calculated out voltage from open circuit voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.10-10
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• 2010

The solar cell energy is considered as a clean energy source in the world. However, because the output of solar cell is not constant, it needs to study the relationships of the DC voltage, the DC current and the DC power of the solar cell. This paper presents the solar cell output characteristics and the maximum power point of the solar cell under different irradiation conditions.

• IEIE Transactions on Smart Processing and Computing
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• v.4 no.2
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• pp.126-131
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• 2015

When a battery is discharging, the battery's current and terminal voltage must both be measured to estimate its state of charge (SOC). If the SOC can be estimated by using only the current or voltage, hardware costs will decrease. This paper proposes an SOC estimation algorithm that needs to measure only the terminal voltage while a battery is discharging. The battery's SOC can be deduced from its open circuit voltage (OCV) through the relationship between SOC and OCV. But when the battery is discharging, it is not possible to measure the OCV due to the voltage drop in the battery's internal resistance (IRdrop). The proposed algorithm calculates OCV by estimating IRdrop using a dynamic terminal voltage measurement. This paper confirms the results of applying the algorithm in a hardware environment via algorithm binarization. To evaluate the algorithm, a Simulink battery model based on actual values was used.