基于燃料电池的推挽正激变换器的控制研究

Research on Control of Fuel Cell Based Push-pull Forward Converter

随着传统能源的耗竭,燃料电池作为一种新型无污染能源受到了广泛的研究。由于燃料电池自身输出电压变化范围大,要有效利用其变化的输出直流电,后级变换器的研制是个重要的环节。该文首先分析了燃料电池外特性较软的特点,然后针对此特点,对现有的控制技术进行分析选择。同时通过对推挽正激变换器的小信号建模,发现平均电流控制技术可以克服这一问题。通过理论分析,设计了变换器的控制参数。最后通过实验验证,表明平均电流控制可以有效解决输入变换器的源效应问题。同时对于变换器整流二极管的反向恢复电压尖峰问题,提出了双CDD无源无损箝位电路。实验结果表明较好地解决了电压尖峰问题,具有一定的工程应用价值。

With the depletion of traditional energy, wide research is focused on the fuel cell which acts as a novel green energy resource. Due to the wide output voltage of the fuel cell, the research on the converter which utilizes the electricity is the key point to exploit the fuel cell effectively. In this paper, the soft character of the fuel cell＇s output voltage is analyzed. According to this character, existing control technology is analyzed and choosed. It can be observed that the average current control can eliminate this problem based on the small signal modeling of the push pull forward converter. The control parameters are designed based on the theoretical analysis. At last, experimental results prove that average current control can solve the source effect problem effectively. At the same time, to solve the reversible voltage spike problem of the rectifying diodes of the converter, double CDD passive and lossless clamp circuits is proposed. Experimental results shows satisfying results and it is valuable to engineering application.