Deterioration diagnosis of electrolytic capacitor in a buck-boost converter

Abstract

A method is proposed for diagnosing the deterioration of an electrolytic capacitor with a finite life span used in the active circuit of a buck-boost converter. Such information is needed for preventive maintenance of DC-to-DC converters. The method is based on the fact that the equivalent series resistance (ESR) of the electrolytic capacitor increases as it deteriorates, which causes in turn an increased ripple in direct proportion to the ESR.<>