Method and device for predicting electrolytic capacitor defects, converter and uninterruptible power supply equipped with such a device

A device for predicting defects in at least one electrolytic capacitor comprising:

• means for measuring a ripple voltage between contact terminals of a capacitor,
• means for measuring the temperature of a capacitor,
• means for determining a value of a current flowing in a capacitor,
• a processing unit comprising first processing means for determining a value of an equivalent series resistance of a capacitor, and second processing means for determining at least one item of information representative of a state of aging of a capacitor from a model for determining a theoretical equivalent series resistance of said capacitor according to the capacitor temperature,
• an output interface, connected to the processing unit, for enabling the information representative of the state of aging of a capacitor to be displayed,
• wherein the first processing means comprises a digital filter for determining the capacitance value of a capacitor, and
• the output interface is for enabling information representative of the capacitance of the capacitor and/or information representative of at least one cause associated with the state of aging of said capacitor according to the value of the capacitance and/or the equivalent series resistance value of the capacitor to be displayed.