Current-sensorless online ESR monitoring of capacitors in boost converter

Abstract

boost circuit has been widely used in photovoltaic generation system and electrolytic capacitor is one of the most vulnerable components in the circuit. Equivalent series resistance (ESR) is an important index to reflect the reliability of capacitor. Real-time online monitoring and evaluation of ESR parameter has great significance to improve the reliability of boost circuit. In this study, a non-invasive online method to monitor and evaluate output capacitor's ESR in boost converter in continuous conduction mode is proposed. The ESR is calculated by sampling two specific periods of output voltage in a switching cycle. The calculation method is verified with the boost circuit model. The experimental results demonstrate the effectiveness of this method.

Keywords

• electrolytic capacitors
• circuit reliability
• switching convertors
• electric resistance measurement
• electrolytic capacitor
• vulnerable components
• equivalent series resistance
• noninvasive online method
• output capacitor
• boost converter
• boost circuit model
• photovoltaic generation system
• ESR parameter evaluation
• current-sensorless online ESR monitoring
• capacitor reliability
• output capacitor ESR evaluation
• output voltage sampling
• switching cycle
• continuous conduction mode