中文摘要：

在开关电源中。铝电解电容广泛应用于各种滤波网络。据统计，铝电解电容是开关电源中故障率最高、最为薄弱的环节。铝电解电容的等效串联电阻（ESR）是反映电容寿命的重要指标。应用一种基于改进EMD和Hilbert变换的新方法，实现ESR值实时估测。该方法对采集的信号进行经验模态分解（EMD），得到一系列本征模函数（IMFs），对所需的IMF进行希尔伯特变换计算ESR。从而得到ESR实时估测值。以Buck电路为例，基于Saber进行仿真实验，结果表明本方法对ESR估测相对误差小于5％，从而为铝电解电容故障与劣化分析提供了新的理论依据和方法。

英文摘要：

Aluminum electrolytic capacitors are usually applied to various filtering networks in switching power supply. According to the statistics data, aluminum electrolytic capacitor is the weakest and the highest failure rate among various power components in the switching power supply. The equivalent series resistance （ESR） of aluminum electrolytic capacitors is an important indicator reflecting capacitor life. Real-time estimation of ESR values of the electrolytic capacitor was realized by proposing a new kind of method based on improved EMD algorithm and Hilbert transform. Using the EMD algorithm, a series of intrinsic mode functions （IMFs） could be achieved. The ESR real-time estimation values can be calculated through Hilbert transform for needed IMFs. Taking Buck circuit for example, simulation experiments were conducted based on Saber. The experimental results show that the ESR estimation error using the proposed method is less than 5%, providing new theoretical basis and method for the analysis of the Aluminum electrolytic capacitor fault and degradation.