Accurate Lifetime Predication of Aluminum Electrolytic Capacitor Considering Equivalent Series Resistance Variations

摘要

Aluminum electrolytic capacitors (Al-Cap) are widely used in the DC-links of many power converters. Al-Cap is of low lifetime, which limits the reliability of the power converter. Therefore, it is important to predict the accurate lifetime of the Al-Cap to assist to design a high reliability power converter. At present, the lifetime prediction model of the Al-Cap is of low precision due to the ignorance of the influence of the AL-Cap's equivalent series resistance (ESR) variation caused by the temperature. The varied ESR increases the energy loss of the Al-Cap, which leads to extra temperature risen. Therefore, this paper investigates the lifetime predication influenced by the ESR variations in an Al-Cap by using Simplorer and Icepak co-simulation. The temperature variation of the Al-Cap is obtained by the Simplorer and Icepak co-simulation. An accurate Al-Cap lifetime predication in a 1kW single-phase inverter is simulated. Simulation result shows that the accuracy of the Al-Cap's lifetime with considering the ESR loss improved over 21% compared that without considering the ESR loss.