摘 要:研究了铝电解电容器的等效模型,讨论了铝电解电容器在不同频率下,其等效串联电容、介质损耗因子、阻抗随频率变化特性,采用Agilent4395A 阻抗分析仪测量了铝电解电容器参数、阻抗-频率特性等。实测证明,实际的铝电解电容器的阻抗-频率特性与理想铝电解电容器的阻抗-频率特性有明显的差异,L e -R e -C 串联等效模型**能代表铝电解电容器的实际模型。
Abstract: an equivalent model of Al electrolytic capacitor has been studied in this paper. The change law of the equivalent serial capacitance, dissipation factor and impedance of Al electrolytic capacitor has been discussed at different frequencies with Agilent4395A Impedance Analyzer. It has been proved that there was a significant difference in the Impedance-frequency Characteristic between the practical Al electrolytic capacitor and the ideal one. This Le-Re-C serial equivalent model could be the practical model of Al electrolytic capacitor.
关 键 词:铝电解电容器;模型;阻抗-频率特性;测试
电源是所有电气设备的心脏。开关电源因具有体积小、重量轻、效率高、发热量低、性能稳定等优点,在我国通信、信息、家电和国防等领域得到广泛应用。无论哪种DC-DC 变换器,主电路使用的元件都是电子开关、电感和电容,如图1所示为Buck 变换器电路,其中铝电解电容器特性对主电路的传递函数有着直接的影响。阻抗-频率特性是铝电解电容器重要的电气参数之一,研究它并建立铝电解电容器等效模型有实际意义。清楚了解影响阻抗-频率特性各因素,既是合理设计电路的基础,也是分析电路失效性的依据。