Title |
Life Estimation of Electrolytic Capacitors for Inverters |
Authors |
이동춘(Lee, Dong-Choon) ; 김형진(Kim, Hyung-Jin) |
Keywords |
Dc link current ; Electrolytic capacitor ; Inveter ; Life estimation |
Abstract |
In this paper, dc link currents for the three-phase diode rectifiers and PWM inverters are analyzed and an algorithm of estimating the life of dc link electrolytic capacitors using the analyzed ripple current is presented. Since the capacitor life is dependent on the operating temperature, the power dissipation in capacitors should be calculated. For this, the ESR(equivalent series resistance) model of the capacitor is derived and ripple currents through the capacitor are analyzed. Relating the power dissipation and the heat transfer equation, the internal operating temperature is calculated. Then, the capacitor life can be predicted by using Arrhenius's equation. An example for applications is given for the practical system. |