Comparison of power decoupling characteristics of DC ripple energy on the single-phase voltage source PWM rectifiers

Abstract

On the single-phase PWM rectifier, it is well known that a power pulsation with twice the utility frequency is contained in the DC-bus. In order to smooth the DC-bus voltage, the electrolytic capacitors with large capacitance have been used. However, the large electrolytic capacitors are bulky and those lifetime becomes short on high ripple current and high temperature environment. Hence, the electrolytic capacitor is not suitable for the DC capacitor, in the case when high power density and long lifetime are expected. The authors studied two kinds of power decoupling circuits, such the authors call a capacitive storage method and an inductive storage method, those enable to transfer the ripple energy appeared on the DC capacitors into the energy in either small capacitors or additional inductors. This paper presents experimental comparison of DC power decoupling characteristics on the single-phase voltage source PWM rectifiers. Finally, the design procedure of optimum application and possibility of high power density is discussed.