Performance Analysis of Electrolytic and Film Type Capacitor

Abstract

This paper deals with the performance analysis of electrolytic and film capacitor in three phase inverter with focus of frequency aspect in ripple current. High capacitance density but low ripple current is produced in electrolytic capacitor alone in DC link of three phase inverter, which degrades the performance of life span of electrolytic capacitor. In order to overcome this problem, Hybrid connection type of capacitor bank is used in order to increase the life span of electrolytic capacitor. A film capacitor is connected parallel with electrolytic capacitor.Film capacitor has, low capacitance density, high ripple current and very reliable. From this combination, electrolytic capacitor has slow absorption of energy whereas film capacitor has absorption of high frequency harmonic. This combination makes longer life span for electrolytic capacitor. In meantime, it reduces the capacitance losses, heating and hotspot temperature rise in electrolytic capacitor. In this paper, analysis of film and electrolytic capacitor is done in MATLAB software and its results are compared.