复合式燃料电池供电系统

提出了一种新型的复合式燃料电池供电系统.它是由燃料电池、蓄电池、单向变换器、双向变换器和逆变器构成.根据燃料电池的特性,提出了复合式全桥三电平LLC谐振变换器和三电平Buck/Boost双向变换器分别作为系统的单向和双向变换器运用于系统中.该结构可以优化能量管理,在冷启动过程由蓄电池向负载供电,而燃料电池不供电,系统易于冷启动;在负载突变时,可由蓄电池提供或吸收动态能量,使得系统具有很好的动态特性;在过载时,燃料电池仅提供额定功率,而过载部分能量由蓄电池提供,燃料电池的功率等级只需按照系统额定功率进行配置,从而降低整个系统的成本.最后在实验室中完成了一个1kW复合式燃料电池供电系统,并对系统进行实验研究,以验证理论分析的正确性.

Hybrid Fuel Cell Power System

This paper proposes a novel hybrid fuel cell power system. It consists of a fuel cell,an isolated uni-directional converter,a bi-directional converter,an inverter and a battery. Fuel cell and battery are connected to the same voltage bus through appropriate hybrid full bridge LLC resonant uni-directional converter and three-level Buck/Boost bi-directional converter respectively. The proposed system can optimize energy management and improve system efficiency. During the start state,battery will power the system,so it is easy to cold start. When the load varies or overload,the fuel cell cannot response immediately,battery will provide or absorb the dynamic power,so the dynamic characteristic of the system can be improved. Fuel cell is the most expensive component over the system. Due to the introduction of battery,peak power can be produced by battery,so the power rating of fuel cell can be decreased,which lead to reduce the total cost. A 1kW hybrid fuel cell power system was built in lab. Experimental results are shown to verify the theoretical analysis.