• 신재생에너지
• /
• 제9권4호
• /
• pp.3-12
• /
• 2013

This paper proposes the hybrid fuel cell system that can solve disadvantages of existing fuel cell system and ensure high reliability and high stability. The system consists of PEM fuel cell, Ni-MH battery and power management system. In this system, when the power provided from the fuel cell is higher than the load power, the extra energy may be used to charge the Ni-MH battery. When the fuel cell can not provide enough energy to the load, the shortage of energy will be supplied by the Ni-MH battery. Experimental results show that the output voltage is regulated well during load variations. Also, high system efficiency is achieved.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 추계학술대회 논문집
• /
• pp.51-54
• /
• 2008

This study aims to devise and analyze a power generation system combining the solid oxide fuel cell and oxy-fuel combustion technology. The fuel cell operates at an elevated pressure, a constituting a SOFC/gas turbine hybrid system. Oxygen is extracted from the high pressure cathode exit gas using ion transport membrane technology and supplied to the oxy-fuel power system. The entire system generates much more power than the fuel cell only system due to increased fuel cell voltage and power addition from oxy-fuel system. More than one third of the power comes out of the oxy-fuel system. The system efficiency is also higher than that of the fuel cell only system. Recovering most of the generated carbon dioxide is major advantage of the system.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2007년도 제29회 추계학술대회논문집
• /
• pp.13-16
• /
• 2007

본 연구에서는 무인기용 추진 시스템으로 연료전지를 사용하였다. 연료전지 추진 시스템은 고항속 무인기를 위한 고에너지 밀도를 갖는 이상적인 대체 동력원이다. 연료전지 동력 시스템은 기폰 배터리의 5배 이상의 에너지 밀도를 제공한다. 액체상태로 저장되는 수소화붕소나트륨을 수소원으로 사용하였다. 수소 생성 시스템은 촉매 반응기, 펌프, 연료, 카트리지, 분리기로 구성된다. 연료전지와 리륨-폴리머 배터리의 하이브리드 동력 관리 시스템이 개발되었다. 모터, 펌프, 팬은 연료전지 시스댐의 피트백 신호에 따라 배터리 동력으로 작동되고 배터리는 연료전지의 잉여 동력으로 재충전되었다.

• Journal of Power Electronics
• /
• 제11권4호
• /
• pp.551-560
• /
• 2011

This paper proposes a grid-tied power conditioning system for the fuel cell power generation, which consists of a 2-stage DC-DC converter and a 3-phase PWM inverter. The 2-stage DC-DC converter boosts the fuel cell stack voltage of 26-48V up to 400V, using a hard-switching boost converter and a high-frequency unregulated LLC resonant converter. The operation of the proposed power conditioning system was verified through simulations with PSCAD/EMTDC software. Based on the simulation results, a laboratory experimental set-up was built with a 1.2kW PEM fuel-cell stack to verify the feasibility of hardware implementation. The developed power conditioning system shows a high efficiency of 91%, which is a very positive result for the commercialization.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
• /
• pp.87-90
• /
• 2007

장기 체공 무인 항공기를 위한 연료 전지 동력 시스템을 개발하였다. 기존의 고압 수소 저장 방식의 문제점을 해결하기 위해 높은 에너지 밀도를 갖는 액상의 화학 수소화물을 연료로 사용하였다. 수소화물을 전환하여 수소를 발생하는 연료 공급 장치는 촉매 반응기, 펌프, 연료 카트리지, 분리기, 제어기로 구성되어 있으며, 전력을 발생하기 위한 연료전지 스택과 함께 연료 전지 동력 시스템을 무인 항공기에 탑재하였다. 연료 전지 동력 시스템을 무인 항공기에 적용하기 위한 성능 검증을 수행하였다.

• 조명전기설비학회논문지
• /
• 제28권3호
• /
• pp.26-31
• /
• 2014

High temperature fuel cell system, such as molten carbonate fuel cells(MCFC) and solid oxide fuel cells(SOFC), are capable of operating at MW rated power output. The power output change of high temperature fuel cell imposes the thermal and mechanical stresses on the fuel cell stack. To minimize the thermal-mechanical stresses on the stack and increase the systems reliability, we should divide the power plant configuration to several banks. However, the improvement of reliability in fuel cell power plant system causes an increase of the investment cost, for example, replacement costs, labor costs, and so on. For this reason - the balance between investment and reliability improvement - many studies about the appropriate level of investment have been conducted. In this paper, we evaluate the cost for operation and installation, the benefit for electric energy and thermal energy sales, and the system reliability for several cases : these cases relate with the bank configuration.

• 마이크로전자및패키징학회지
• /
• 제13권3호
• /
• pp.19-26
• /
• 2006

본 논문은 예비 전력공급설비의 일환으로 비상시 소방 방재설비에 적용되는 연료전지 발전시스템에 대해 연구된다. 제안된 시스템은 비상시 상용 전력공급의 차단에 대비하여 소방 방재설비들의 전력공급원으로 이용된다. 연료전지 발전시스템에서 가장 손실이 큰 부분은 전력변환부이다. 또한 전력변환부의 손실은 전력변환을 위해 사용된 전력용 반도체 스위치의 스위칭 손실로 주어진다. 본 논문에서는 이러한 연료전지 발전시스템의 출력을 최대한 활용하기 위하여 부분공진의 기법이 적용된 고효율의 전력변환기가 제안된다. 또한 연료전지 발전시스템에 적용된 고효율 전력변환기는 비절연형으로 설계되고 사용된 제어스위치들은 새로운 소프트 스위칭 회로토폴로지에 의해 무손실로 동작되어 시스템의 효율을 증대시킨다. 다양한 컴퓨터 시뮬레이션과 특성실험을 통해 이론적 해석의 타당성이 입증된다.

• 전기학회논문지
• /
• 제60권6호
• /
• pp.1280-1285
• /
• 2011

Recently, due to the use of fossil fuels for electric power production, carbon emissions increased excessively. Thereby, in order to replace fossil fuels, many studies about fossil fuels such as solar and fuel cell energy source are progressing. Fuel cell system has high energy conversion efficiency. Also, fuel cell system is environmentally friendly system because the carbon emission is almost not occur. Therefore, the fuel cell system is considered as the core technology of in the fields of the future energy and environmental. Fuel cell system has an effect on distribution power system because another power source of other than large power plants. So, fuel cell system can be degradation reason of power quality in the power system. In this paper, we constructed the system for an assessment on harmonics effect. The system is composed with power source, harmonics generation and linear load, fuel cell system. we also performed assessment on harmonics effect in customer and the distributed power system during grid connection of residential fuel cell system. An assessment cases are divided into three. A Case 1 is state that residential load and fuel system are connected to grid, Case 2 is state that residential load and harmonics load are connected to grid, and Case 3 is state that all loads are connected to grid. As a output of fuel cell system is increase, analysis results based on assessment system showed that power quality became more aggravation as effect of harmonics.

• 전기학회논문지
• /
• 제58권8호
• /
• pp.1551-1558
• /
• 2009

This paper proposes a new power conditioning system for the fuel cell power generation, which consists of a LLC resonant DC-DC converter and 3-phase inverter. The LLC resonant converter boosts the fuel cell voltage of 26-48V up to 400V, using the hard-switching boost converter and the high-frequency ZVS half-bridge converter. The operation of proposed power conditioning system was verified through simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was verified through experimental works with a laboratory prototype, which was built with 1.2kW PEM fuel-cell stack, 1kW LLC resonant converter, and 3kW PWM inverter. The proposed system can be utilized to commercialize a real interconnection system for the fuel-cell power generation.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2005년도 춘계학술대회
• /
• pp.361-365
• /
• 2005

Since the fuel cell uses the hydrogen for its fuel. it has no emission and higher efficiency than an internal combustion engine. Also fuel cell is much quieter than engine generator and generates heat much less than engine generator. So it has advantage of Army's 'si lent watch' capability and the ability to operate undetected by the enemy. The fuel cell hybrid system combines a fuel cell power system with an ESS. The ESS (e.g., batteries or ultracapacitors) reduces the fuel cell's peak power and transient response requirements. It allows the fuel cell to operate more efficiently and recovery of vehicle energy during deceleration. The battery has high energy density, so it has the advantage regarding driving distance. However, it has a disadvantage considering dynamic characteristic because of low power density. One other hand. the ultracapacitor has higher power density, so it can handle sudden change or discharge of required power. Yet. it has lower energy density. so it will be bigger and heavier than the battery when it has the same energy. This paper proposes the power management strategy for multi-power source fuel cell hybrid system. which is applied with the merits of both battery and ultra capacitor by using both of them simultaneous.