【作者】 周雷；

【导师】 王萍；

【作者基本信息】 天津大学 ， 电气工程， 2018， 硕士

【摘要】 随着社会的不断发展,全球能源危机形势和环境污染问题日益严峻。传统化石能源因为其不可再生性和带来的一系列环境污染问题,已经不能满足人类对能源的需求,寻找能够代替传统化石能源的新能源已经成为当务之急。燃料电池电动汽车是新能源技术在交通领域中的一种重要应用,其具有零排放,高能量转换率等优点。但是燃料电池输出电压较低、输出特性软,需要使用宽增益升压直流变换器将其与电动汽车的高压直流母线电压等级相匹配。另外为了保证燃料电池的使用寿命,要求所用变换器有较小的输入电流纹波。本文首先介绍了几种典型的升压直流变换器拓扑,分析了各个变换器存在的问题,在此基础上结合各个变换器的优点,分别提出了单功率开关宽增益Boost直流变换器和输入并联-输出串联宽增益Boost直流变换器。单功率开关宽增益Boost直流变换器采用二极管-电容网络,通过对电容进行并联充电以及电压箝位,提高了电压增益。输入并联-输出串联宽增益Boost直流变换器采用交错并联结构,减小了输入电流纹波,输出侧两个电容串联,提高了电压增益。本文对两种变换器的运行机理与稳态工作性能进行了详细分析。本文为两种变换器分别建立了输出电压400V、输出功率1.6kW、开关频率20kHz的实验样机,验证了两种变换器都具有较宽的电压增益(3.3~8倍)。实验结果证明了提出的两种变换器的有效性和理论分析的正确性,二者皆适用于燃料电池电动汽车。更多还原

【Abstract】 Traditional fossil fuel resources are depleting quickly,but their continued use contributes to increasing pollution.Development of clean energy systems is essential.With regard to transport,fuel cell vehicles can be considered one of the most essential applications for clean-energy.Fuel cell vehicles can provide clean propulsion power with zero emission,as well as higher energy utilization.However,the use of fuel cells brings challenges,particularly with their low output voltage and “soft” output characteristic.So the fuel cells must be interfaced to the main DC link bus through a step-up DC-DC converter with a wide range of voltage-gain.In addition the input current ripple of the converter for fuel cells must be low enough to prevent accelerated reduction of the life time of the fuel cell.Several typical DC-DC converters has been discussed in this paper.Combining the advantages of these converters,single-switch,wide voltage-gain range boost DC-DC converter and input-parallel output-series DC-DC boost converter with a wide voltage-gain range have been proposed in this paper,respectively.Diode-capacitor structure has been used in single-switch,wide voltage-gain range boost DC-DC converter.The capacitors are charged in parallel and discharged in series which can improve the voltage-gain of the converter.As for the input-parallel output-series DC-DC boost converter with a wide voltage-gain range,an interleaved structure is adopted in the input side to reduce input current ripple.Two capacitors are connected in series on the output side to achieve a high voltage-gain.The operating principles and steady-state characteristics of two converters are presented and analyzed in this paper.Two 400 V,1.6kW,20 kHz experimental prototypes are developed for the converters,and the converters both achieve the wide voltage-gain range(3.3~8).The experimental results validate the effectiveness and feasibility of the proposed converters and their suitability as a power interface for fuel cell vehicles.更多还原