• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.376-379
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• 2006

In this paper, stack voltage monitoring module is developed which monitor cell voltage of the fuel cell stack and transfer it to the main controller for monitoring fault and stopping drive when the trouble is happened in the fuel cell stack. Especially, the circuit, for monitoring each cell voltage of several hundreds cells in stack, is designed and analyzed. The connector is also developed for making wire harness simple and low cost because wire harness is complicated when the cells are connect each monitoring circuit.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.388-391
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• 2005

In this paper, Cell voltage monitoring method is studied for fault detection of PEMFC(Proton Exchange Membrane Fuel Cell) for FCEV(fuel cell electric vehicle). To measuring several hundred of cells in fuel cell stack, The demanded feature of hardware and software is studied and several types are analysed. Finally, $3.26\%$ maximum measuring error is acquired and verified experimentally.

• 한국자동차공학회논문집
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• 제22권7호
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• pp.76-83
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• 2014

During PEMFC(Proton Exchange Membrane Fuel Cell) operation monitoring and diagnosis are important issues for reliability and durability. Stack defect can be followed by a critical cell voltage drop in the stack. One method for monitoring the cell voltage is CVM(Cell Voltage Monitoring), where all cells in the stack are electrically connected to a voltage measuring system and monitored these voltages. The other methods are based on the EIS(Electrochemical Impedance Spectroscopy) and on nonlinear frequency response. In this paper, intermodulation(IM) method for diagnosis PEMFC stack is introduced. To detect one or more critical PEMFC cell voltage PEMFC stack is excited by two or more test sinusoid current, and the frequency response of the stack voltage is analyzed. If one or more critical cell voltage exists, higher harmonics on the voltage frequency spectrum will appear. For the proposed IM method, stack simulation and experiments are conducted.

• 한국위성정보통신학회논문지
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• 제8권3호
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• pp.15-19
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• 2013

리튬이온 배터리는 낮은 자체 방전율 특성과 고밀도 에너지 저장장치로 다양하게 응용되고 있으며, 단위 셀 배터리의 전압은 4V 보다 낮아, 직렬로 연결하여 사용해야 하는 것이 일반적이다. 배터리 셀전압의 직렬 연결 동작시, 각각의 단위 셀 배터리는 내부저항이 균일하지 않아, 충전 시, 특정 단위 셀 배터리는 4V 이상이 걸려, 폭발이 발생할 수도 있으며, 또한, 방전 시 배터리의 특성을 떨어뜨릴 수 있는 한계 전압 이하가 되는 심각한 문제가 존재한다. 따라서, 단위 셀 배터리의 충전 및 방전 동작에서는 과충전과 과방전을 사전에 감지하기 위한 전압 센싱 동작이 필요하며, 이에, 본 논문에서는 고속 배터리 전압 센싱 모듈 개발을 소개한다. 제작된 CVM(Cell Voltage Monitoring)은 단위 배터리 셀을 통하여, 전압 및 온도 채널 포함하여, 12채널을 모니터링할 수 있으며, 채널당 12-bits 분해능과 192 kbps 전송 속도를 가진다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.569-572
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• 2007

In this paper, research about SVM(stack voltage monitoring) module is written, which studied to detect the failure mode of stack and stop stack driving. It is important role for SVM module to monitor the cell voltage and also, transfer those data to Supervisor controller. SVM module needs accurate measurement to detect failure mode, because the cell voltage is very small value under a few [V]. For improving these cost and technical efficiency, the electric characteristic experiment is made with the measurement circuit designed by using precision resistor.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 전력전자학술대회 논문집
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• pp.401-402
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• 2015

In this paper a direct cell-to-cell charge balancing circuit which can transfer the charge from any cell to any cell in the battery string is introduced. In the proposed topology the energy in the high voltage cell is transferred to the low voltage cell through the simple operation of a dc-dc converter to get fast equalization. Furthermore, the charge equalization can be performed regardless of the battery module operation whether it is being charged, discharged or relaxed. The monitoring circuit composed of a DSP and a battery monitoring IC is designed to monitor the cell voltage and protect the battery. In order to demonstrate the advantages of the proposed topology, a prototype circuit was designed and applied to 12 Lithium-Ion battery module. It has been verified with the experiments that the charge equalization time of the proposed method was shortest compared with those of other methods.

• 전자공학회논문지A
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• 제32A권11호
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• pp.71-78
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• 1995

Based on the popular 4-transistor SRAM cell, an analytical expression of the minimum cell ratio was derived by modeling the static read operation. By analyzing the relatively simple expression for the minimum cell ratio, which was derived assuming the ideal transistor characteristics, effects of the changes in supply voltage and process parameters on the minimum cell ratio was predicted, and the minimum power supply voltage for read operation was determined. The results were verified by simulations utilizing the suggested simulation method, which is suitable for monitoring the lower limit of supply voltage for proper cell operation. From the analysis, it was shown that the worst condition for cell operation is low temperature and low supply voltage, and that the operation margin can be effectively improved by reducing the threshold voltage of the cell transistors.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 추계학술대회 논문집
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• pp.7-8
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• 2015

In this paper a cell-to-cell fast charge balancing circuit for the Lithium-Ion battery module is proposed. In the proposed topology the energy in a high voltage cell is transferred directly to a low voltage cell through the operation of the dc-dc converter. Furthermore, the charge balancing can be performed regardless of the battery operation whether it is being charged, discharged or relaxed. The monitoring circuit composed of a DSP and a battery monitoring IC is designed to monitor the cell voltage and detect the inferior cell thereby protecting the battery module from failure. In order to demonstrate the performance of the proposed topology, a prototype circuit was designed and applied to 12 Lithium-Ion battery module. It has been verified with the experiments that the charge equalization time of the proposed method was shorter compared with those of other methods.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1031_1032
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• 2009

The voltages of unit cells of a fuel cell stack are one of the most significant factors to detect failure conditions and thereof safely control and operate the fuel cell system. In this paper, we describe two methods to monitor the voltages of the unit cells of a stack in consideration of data accuracy, circuit extensibility to various numbers of cells, and cost. The reported methods are approached by (i) the power isolation of cell voltage monitoring part from the communications part and (ii) the utilization of a commercially available cell monitoring integrated circuit IC of a Li-ion battery.

• 한국항공우주학회지
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• 제33권2호
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• pp.113-118
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• 2005

본 논문은 한쪽 또는 양쪽의 측정 점들이 종래의 차동증폭기에서 허용되는 전압 범위를 초과할 때 차동전압 측정을 위한 인공위성 배터리 셀 전압 감시 시스템을 제시하였다. 본 시스템은 다수개의 직렬로 연결된 셀들로 구성된 재충전 가능한 인공위성 배터리에서 몇몇의 셀 전압들이 높은 공통모드 전압에서 측정될 때 각 셀 전압 감시를 위해 특히 유용하다.