Lifetme Estimation for Aluminum Electrolytic Capacitor in Active Power Quality Controllers considering Load Conditions

Active power quality controllers have been widely used in distribution network to improve power quality. Aluminum electrolytic capacitor is extensively adopted as the DC bus of the device due to its volume and cost, but it also brings reliability issues to the whole device. This paper presents a calculation method for the spectrum of the DC current considering the load’s reactive power and unbalanced active power and conducts the lifetime estimation of the aluminum electrolytic capacitor combining with its characteristics. Thus, the DC bus design of the device can be optimized with the estimation result. The theoretical analysis is verified in a 0.4kV distribution network.