Electrolytic Capacitor Failure Mechanism Due to Inrush Current

One of the most critical application parameters of an aluminum electrolytic capacitor is its voltage capability, typically expressed in terms of rated or working voltage, surge voltage, transient voltage, etc. Exceeding the voltage capability (even for a few milliseconds) can result in the immediate failure of the capacitor, or its performance can be degraded over the longer term due to high in-rush current. Electrolytic capacitor failure modeling due to in-rush current is presented followed by experimental results.