14.4kW PEMFC电堆单体电压均衡性实验研究

发布时间：2018-05-06 06:19

本文选题：质子交换膜燃料电池 + 电压均衡性　；参考：《西南交通大学学报》2017年03期

【摘要】：质子交换膜燃料电池(proton exchange membrane fuel cell,PEMFC)电堆由多个单电池串联叠加而成,材料、工艺和流场分布等因素可能引起单电池性能衰减,电堆运行寿命取决于电压最低的单体电池,电堆中单体电池电压均衡性是影响燃料电池寿命的重要因素.为了解决现有单体电压均衡性评价方法不能全面准确地反映燃料电池电压一致性的问题,探究电堆电流、流场分布和空间位置对单体电压波动率的影响,以14.4 k W PEMFC电堆测试平台为基础进行了单体电压均衡性实验研究.实验分别测试稳态时电堆电流以10 A为步长、从10 A加载到180 A和暂态时从47 A动态加载到112 A的单体电压波动率,加载策略采用恒频恒幅加载控制策略,负载加载的时间间隔为20 ms,电流加载幅值为2 A.首先,运用统计学"掐头去尾"的原则处理电堆稳态电流从10 A加载到180 A的数据,剔除端部单电池前(后)单体电压波动率与电流,分别得到Fourier 3项式和Gaussian2项式函数关系.然后,针对单体电压波动率无法分析电堆电压幅差和故障的缺点,提出将单体电压波动幅值、异众比率、最小距和电压平均差相结合的改进电压均衡性评价方法.该方法以单体电压波动幅值推断电堆电压波动范围,并通过异众比率判断较大电压偏差电池占所有单电池数目的比例,使用最小距表示电压最低的单体电池偏移电堆平均电压的程度,利用电压平均差评价电堆整体波动大小.最后,以电堆从47 A动态加载到112 A时的75片单体电压分布为算例,对传统单体电压波动率与改进的电压均衡性评价方法做对比实验.研究结果表明:虽然传统的单体电压均衡性评价方法测得的波动率为0.77,但很难从电压波动率上反映出电堆各单体电池电压波动程度;改进的电压均衡性评价方法可从电堆单体电压波动幅值、异众比率、最小距和电压平均差多方面综合评价电压的均衡性,其对比实验值分别为40.00、0.04、14.33 m V和2.60 m V,电堆电压幅差较大;电压波动较大的单电池的数量很少,电压最低的单体电池偏移电堆平均电压的程度较小,电堆电压整体波动较小,电堆整体均衡性较好.
[Abstract]:Proton exchange membrane fuel cell (PEMFC) stack consists of several single cells in series. The material, process and flow field distribution may cause the single cell performance attenuation, and the stack life depends on the single cell with the lowest voltage. The voltage equalization of single cell is an important factor to affect the life of fuel cell in stack. In order to solve the problem that the existing single cell voltage equalization evaluation methods can not reflect the consistency of fuel cell voltage completely and accurately, the effects of stack current, flow field distribution and space location on the voltage fluctuation rate of fuel cell are explored. Based on the 14.4kW PEMFC stack test platform, an experimental study on the voltage equalization of monomers has been carried out. The steady-state voltage fluctuation rate of the stack with 10A step, from 10A to 180A and transient from 47A to 112A is measured respectively. The loading strategy adopts constant frequency and constant amplitude loading control strategy. The loading time interval is 20 Ms and the current loading amplitude is 2 A. Firstly, the data of steady current loading from 10A to 180A are processed by the principle of "strangling head and tail" in statistics. After removing the voltage fluctuation rate and current in front (back) of the terminal single cell, the functional relationships of three terms of Fourier and one term of Gaussian2 are obtained, respectively. Then, aiming at the disadvantage that voltage fluctuation rate can not analyze voltage amplitude difference and fault of stack, an improved voltage equalization evaluation method is proposed, which combines single voltage fluctuation amplitude, heterogeneity ratio, minimum distance and voltage average difference. In this method, the voltage fluctuation range of stack is inferred from the amplitude of single voltage fluctuation, and the proportion of large voltage deviation cells to all single cells is judged by the heterogeneity ratio. The minimum distance is used to represent the average voltage of the cell offset stack with the lowest voltage, and the voltage average difference is used to evaluate the overall fluctuation of the stack. Finally, taking the voltage distribution of 75 monolayers loaded dynamically from 47A to 112A as an example, a comparative experiment is made between the traditional voltage fluctuation rate and the improved voltage equalization evaluation method. The results show that although the volatility rate measured by the traditional method is 0.77, it is difficult to reflect the voltage fluctuation of each single cell in the stack from the voltage fluctuation. The improved voltage equalization evaluation method can comprehensively evaluate the voltage equalization from the aspects of voltage fluctuation amplitude, heterodyne ratio, minimum distance and voltage average difference. The comparative experimental values are 40.004 ~ 0.04 ~ 14.33 MV and 2.60 MV respectively, the voltage amplitude difference of stack is large, the number of single cell with high voltage fluctuation is very small, the average voltage of single cell with the lowest voltage is small, and the voltage fluctuation of stack as a whole is relatively small. The overall balance of the stack is good.
【作者单位】：西南交通大学电气工程学院;中国电力工程顾问集团东北电力设计院有限公司;
【基金】：国家自然科学基金青年基金资助项目(51607149) 四川省科技服务业平台建设项目(2015GFW0022)
【分类号】：TM911.4

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