• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.2
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• pp.126-133
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• 2017

The conventional battery charger requires two separate voltage and current compensators to achieve constant current and constant-current-charging profile. This compensator configuration leads to an inevitable transient response during the mode change between the constant current and the constant voltage operation. Futhermore, a tedious and complicated design process is required to consider a widely changing battery voltage and the nonlinear electrical properties of Li-ion battery. This study proposes a single integrated voltage-current compensator of the LLC resonant converter for Li-ion battery charger applications to overcome the aforementioned drawbacks. The proposed compensator is designed to provide a smooth and reliable performance during the entire charging process while providing the reduced design efforts and seamless mode transient response. Several experimental results based on a 300 W prototype converter and its theoretical analysis are provided to verify the effectiveness of the proposed compensator.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.65-66
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• 2014

본 논문에서는 부하평준화를 통한 전기요금 절감효과, 무효전력 보상을 통한 역률 개선 및 비상부하 전원공급을 위한 독립운전 기능을 갖는 MW급 ESS에서 PCS뿐 아니라 배터리, 변압기, 각종부하 및 디젤발전기 등 계통 내 구성 요소들을 실제 사양 및 데이터를 기반으로 모델링하였다. 또한 1MW PCS를 위한 유 무효전력, CC-CV 충전 및 독립운전 제어알고리즘을 개발하였으며 시뮬레이션 및 축소시험을 통해 본 논문의 타당성을 검증하였다.

• Proceedings of the KIPE Conference
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• 2014.07a
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• pp.191-192
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• 2014

Multiple output converters (MOCs) are widely used for applications which require various levels of the output voltages due to their benefits in cost, volume, and efficiency. However, most of the MOCs developed so far can regulate only one output tightly and require as many secondary windings in the transformer as the number of the outputs. In this paper, a novel Time Division Multiple Control (TDMC) method to regulate all the outputs in high precision is proposed and applied for the multiple output battery charger based on the phase shift full bridge topology to charge a multiple number of batteries at one time. The proposed converter can charge three different kinds of batteries or same kind of batteries in different state of charges (SOCs) by using constant current/constant voltage (CC/CV) charge mode independently. At the same time it can provide an even degree of tight regulation for each output to satisfy the strict ripple requirement of the battery. The validity and feasibility of the proposed method are verified through the experiments.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.399-400
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• 2012

The proposed battery charger presented in this paper is suitable for Lead-Acid Battery and the dc/dc buck converter topology is applied as a charger circuit. The technique adopted in this charger is constant current & constant voltage dual mode, which is decided by the value of voltage of proposed battery. Automatic mode change function is detected by the percentage value of level of battery charging. CC Mode (Constant Current Mode) is operated when charging level is below 80% of the total charging of Battery voltage and above 80% of battery voltage charging, CV Mode (Constant Voltage Mode) is automatically operated. As the charging level exceeds 120%, it automatically terminates charging. The feedback signal to the PWM generator for charging the battery is controlled by using the current and voltage measurement circuits simultaneously. This technique will degrade the damage of proposed type of battery and improve the power efficiency of charger. Finally, a prototype charger circuit designed for a 12-V 7-Ah lead acid battery is constructed and tested to confirm the theoretical predictions. Satisfactory performance is obtained from simulation and the experimental results.

• Journal of Pharmacopuncture
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• v.5 no.1 s.8
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• pp.7-26
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• 2002

Objective: The purpose of this study was to investigate acute and subacute toxicity and sarcoma-180 anti-cancer effects of herbal acupuncture with Carthami- Tinctorii fructus (CF) in mice and rats. Method: Balb/c mice were injected intraperitoneally with Carthami - Tinctorii fructus (CF) for $LD_{50}$ and acute toxicity test. Sprague Dawley rats were injected intraperitoneally with Carthami- Tinctorii fructus (CF) for subacute toxicity test. The Carthami- Tinctorii fructus herbal-acupuncture was injected on Chung-wan (CV12) of mice with Sarcoma-180 cancer cell line. Results: 1. $LD_{50}$ was uncountable as none of the subjects expired during the test. 2. In acute toxicity test, toxic symptoms were not detected, but the body weight of mice was increased in treatment Ⅰ, treatment Ⅱ groups, compared to the normal group.(p<0.05) 3. In acute toxicity test of serum biochemical values of mice, glucose was increased in treatment Ⅰ and treatment Ⅱ groups, total cholesterol was increased in treatment I group, GOT was decreased in treatment Ⅱ group, and GPT was decreased in treatment Ⅰ group, compared to the normal group.(p<0.05) 4. The clinical signs and the body weight of mice treated with 0.1 cc, 0.2cc Carthami- Tinctorii fructus (CF) were not affected during the subacute toxicity test. 5. In subacute toxicity test, treatment groups didn't show significant changes in complete blood count test (CBC) of rats, compared to the nonnal group.(p<0.05) 6. In subacute toxicity test of serum biochemical values of rats, uric acid was decreased in treatment Ⅰ and treatment Ⅱ groups, compared to the nonnal group, triglyceride was decreased in treatment I group, compared to the normal group, GOT and GPT were decreased in treatment I and treatment Ⅱ groups, and alkaline phosphatase was decreased in treatment Ⅰ and treatment Ⅱ groups, compared to the normal group.(p<0.05) 7. Median survival time was increased in all the treatment groups for Sarcoma-180 cancer cell treated with Carthmni- Tinctorii fructus (CF).(p<0.05) 8. Natural killer cell activity was significantly increased in all the treatment groups compared to the normal group.(p<0.05) 9. Interleukin-2 productivity was decreased in treatment Ⅰ and treatment Ⅱ groups.(p<0.05) Conclusion: According to the results, we can conclude herbal-acupuncture of Carthami-Tinctoriifructus (CF) caused negligible toxkity, and had anti-tumor effects in mice.

• Journal of Pharmacopuncture
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• v.5 no.1 s.8
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• pp.61-79
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• 2002

Objective: The purpose of this study was to investigate acute and subacute toxicity and sarcoma-180 anti-cancer effects of Herbal acupuncture with Anneniacae amarum semen (Haeng-in) in mice and rats. Method: Balble mice were injected intraperitoneany with Haeng-In extract for $LD_{50}$ and acute toxicity test. Sprague-Dawley rats were injected intraperitoneally with Haeng-In extract for subacute toxicity test. TheAnneniacae amarum semen Herbal-Acupuncture was injected on Chung-wan (CV12) of mice with Sarcoma-180 cancer cell line. Results: 1. $LD_{50}$ was uncountable as none of the subjects expired from the treatment groups during the test. 2. The clinical signs and the body weight of mice treated with 0.1cc and 0.2cc Haeng-In extract were not affected during the acute toxicity test. 3. In acute toxicity test of serum biochemical values of mice, total protein and albumin were decreased in treatment group Ⅰ. Glucose was increased, and total cholesterol was decreased in treatment groups. GPT was increased in treatment group Ⅰ. 4. In subacute toxicity test, toxic symptoms were not detected in the treatment groups. 5. In subacute toxicity test, the body weight was increased in treatment groups on 14th and 21st day. 6. In subacute toxicity test. liver weight was increased in treatment group Ⅱ, and spleen weight was increased in treatment group Ⅱ. Lung weight was increased in an the treatment groups.(p<0.05) 7. In subacute toxicity test, severe tissue injury was found in lung and liver, especially treatment group Ⅰshowed more significant lung damage compared to treatment group l. 8. In subacute toxicity test, WBC. MCH and MCHC were increased in an the treatment groups, RBC, HGB and HCT were decreased in treatment group H(p<0.05). 9. In subacute toxicity test of serum biochemical values of rats, triglyceride was decreased in all the treatment groups. ALP was decreased in treatment group Ⅰ. and creatinine was decreased in treatment group Ⅱ. BUN/CR was increased in treatment group Ⅱ(p<0.05). 10. Median survival time of Sarcoma-180 cancer cell treated with Haeng-In was increased in all the treatment groups by twenty percent, compared to the control group(p<0.05). 11. Natural killer cell activity about the Sarcoma-180 cell was decreased at the ratio of 100:1 but was increased at the ratio of 10:1. In treatment group Ⅱ, increase was found at the ratio of 100:1 and 50:1 (p<0.05). 12. Interleukin-2 productivity of the Sarcoma-180 cell was decreased in treatment group I, but was increased in treatment group Ⅱ(p<0.05). Conclusion: According to the results, we can conclude Herbal-acupuncture with Anneniacae amarum semen caused toxicity, and had effects in Sarcoma-180 cancer cell.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.444-453
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• 2017

This paper proposes an operational algorithm for a Photovoltaic Power-Hardware-In-Loop Simulator that is designed to improve the control algorithm and reliability of the PV Inverter. There was an instability problem in the PV PHILS with the conventional algorithm when it was connected tothe PV inverter. Initially, a real-time based computing unit with mathematical modeling of the PV array is implemented and a DC amplifier and an isolated device for DC power measurement are integrated. Several experiments were performed based on theabove concept undercertain conditions, which showed that the proposed algorithm is more effective for the PV characteristic test and grid evaluation test than the conventional method.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.24-27
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• 2016

In this study, a 1kW Solid Oxide Fuel Cell(SOFC) test system was developed. A SOFC is the most promising power system to provide the higher efficient(over 50%) for house application area(1~10kW). To develop the optimized test system, the temperature control module that controls the preprocess and reaction condition, the flow control module that controls of the mass of reactants, and the electric loader that tests the discharge performance condition, etc. The temperature control module was designed to provide the high control resolution(under $1^{\circ}C$ at $750^{\circ}C$ of operating temperature) using K-type thermal couple. The flow control module was designed control blower and heater precisely using the phase control method. And the electric loader is designed that provide CV, CC, CR discharge mode and minimized the operating error adopting the independent DC-DC converter on analog input and output module. The performance of the developed SOFC test system showed that the accuracy of stack voltage was 0.15% at 80V and stack current was 0.1% at 100A.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.193-198
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• 2012

An LED converter used to operate an LED with high efficiency and long lifespan, activates an LED by keeping voltage and current constant. In spite of voltage drop by LED's overheating and over-voltage by damage of a power line and by circuit problem, most existing LED converters supply unchanged constant voltage and current to the LED. Eventually, LED is out of order because of over-voltage or over-current. To avoid the breakdown of an LED by over-voltage and over-current, we propose a new scheme which deactivate the PWM circuit in the event of over-current generating. The PWM circuit operates below the pre-determined level of current. While the over-voltage is generated in PWM circuit, the feedback circuit makes the PWM circuit stopped and therefore prevents LED from being damaged by over-voltage and over-current.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.5
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• pp.369-375
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• 2010

This paper presents a design and implementation of 3.3 kW on-board battery charger for electric vehicles or plug-in hybrid electric vehicles. Considering characteristics of the electric vehicles, a series-loaded resonant dc-dc converter and frequency control scheme are adopted to improve efficiency and reliability, and to reduce volume and cost. The developed on-board battery charger is designed and implemented by using high frequency of 80-130 kHz and zero voltage switching method. The experimental result indicates 92.5% of the maximum efficiency, 5.84 liters in volume, and 5.8kg in weight through optimal hardware design.