Minimizing the Usage of Electrolytic Capacitors and Smoothening the Dc Bus Voltage Ripples By Using Eliminators to Improve Power Quality

Abstract

In this paper the control strategies for elimination of DC bus voltage ripples are proposed and usage of electrolytic capacitors is minimized by pulse width modulation (PWM) based rectifying approach and continuous conduction mode(CCM). The control strategies could improve the performance of ripple eliminators. The voltage/current ripples has become a primary power quality issue for dc systems. In this paper, a single-phase Pulse width modulation-controlled rectifier is taken as an example to investigate how active control strategies can improve the power quality of dc systems, reduce voltage ripples, and, at the same time, reduce the usage of electrolytic capacitors. The concept of ripple eliminators recently proposed in the literature is further developed, and the ratio of capacitance reduction is analyzed. An advanced controller on the basis of the repetitive control is proposed for one possible implementation of ripple eliminators in the continuous current mode (CCM). By using the simulation results we can verify the effectiveness of the strategy with comparison to another ripple eliminator operated in the discontinuous current mode.