燃料电池发电系统前端DCDC变换器的研究解析

山东科技大学学士学位论文

摘要

燃料电池是一种将化学能直接转化为电能的装置，是一种高效的绿色能源，具有功率密度大、高效洁净、运行稳定可靠等优点，日益受到人们的青睐，成为最有前景的能源技术之一。

但燃料电池本机输出电压一般不高，输出的直流电压随着负载的变化有很大的变动范围，因此在燃料电池发电系统中，具有升压稳压功能的功率变换是其重要组成部分。燃料电池输出的电压必须经过具有升压稳压功能的功率变换装置，将不稳定的直流电变换成符合要求的直流或交流电。

本文主要研究了燃料电池发电系统中的直流变换器。首先，本论文介绍了燃料电池的原理、特点和选题意义，并对质子交换膜燃料电池的输出特性做了分析。其次，列举并比较了常见的DC/DC变换器的拓扑结构和性能，借鉴国内外在燃料电池系统中直流变换器上的研究和创新成果，根据燃料电池的输出特性及电动汽车的特点，选用Boost 型电路结构作为直流变换电路。再次，本课题的设计目标：将 5 KW质子交换膜燃料电池组85的输出电压，转换成375V左右的电压，为5KW轻型车辆提供主~

120

V

动力。根据对Boost电路原理的分析，推导并设置电路主要元件的参数，利用Multisim、Matlab/Simulink软件进行建模和仿真，观察并分析输出电压、纹波电压、开关管电压和电流等波形，分析该方案的可行性和不足之处。

关键词: 燃料电池 DC/DC变换器 Boost电路 Multisim Matlab/Simulink

燃料电池发电系统前端DC/DC变换器的研究

ABSTRACT

Fuel cell is a device which can transform chemical energy directly into electric energy. It is a green energy of high efficiency .which has various advantages such as high efficiency of power generation and density, environment friendly, stability and reliable operation, so it is regarded seriously by more and more people,becoming one of the most promising energy technology.

However, the output voltage of the FC is not always very high and varies largely as the load changes.Therefore, power converter is essential in the Fuel cell generation system.which can boost the voltage of the FC and stabilize the voltage of the output of the power converter, in order to get required DC or AC.

This paper mainly studies the DC/DC converter of the fuel cell generation system..This paper first introduces the background of selection of this subject, analyses the working theory and the output performance of PEMFC.Then, the paper introduces different innovation in DC/DC converters used in fuel cell system .What is followed is the key part, according to the characteristics of the electric vehicle and fuel cell system, boost circuit is chosed to topologies of DC/DC converter. Meanwhile, the paper presents the development and accomplish the conversion,and given analysis of the working principle of the circuit .The goal of the design is to boost the output voltage of 5KW PEMFC system varing between 85~120 V, to about 375V so that it can be inverted to 220V AC to supply for the light vehicle.With theoretical studying the design,criterions of key circuit parameters are gained,finally the author simulates the boost circuit for fuel cell with the software Multisim and Matlab/Simulink, in the end analyses the output waves,the advantages and disadvantages of this design.

Key words:fuel cell DC/DC converter Boost circuit Multisim Matlab/Simulink

山东科技大学学士学位论文

目录

1 绪论 (1)

1.1 本课题的背景及意义 (1)

1.2 燃料电池的工作原理 (2)

1.3 燃料电池的工作特性 (4)

2 常见的直流变换器 (6)

2.1 基本元器件及技术 (6)

2.2 基本的直流变换器 (9)

3 直流变换器的设计 (12)

3.1 直流变换器的性能要求 (12)

3.2 国内外的研究发展 (13)

3.3电动汽车中变换器的设计 (14)

4 boost变换器的建模与仿真 (20)

4.1 Boost电路参数的设计 (21)

4.2 Boost电路的建模与仿真 (23)

4.3 本方案的优缺点分析 (32)

5 结束语 (34)

参考文献 (35)

致谢辞 (37)

附录 (38)