Compensation of DC-Link Oscillation in Single-Phase-to-Single-Phase VSC/CSC and Power Density Comparison

Abstract

This paper proposes a technique to reduce the low-frequency dc-link energy oscillation due to the pulsating single-phase energy flow in a single-phase-to-single-phase voltage source converter (VSC) and current source converter (CSC), which operate connected to the grid. This pulsating energy is the major factor for increasing the size of the passive components and power losses in the converter. Pulsation reduction is achieved by incorporating two auxiliary active switches and one passive energy storage element to the rectifier and inverter sides. Additionally, this paper presents the comparison of these converters (VSC/CSC) regarding efficiency and power density. Details of the control strategy are presented. Simulation and experimental results are provided to validate the theoretical approach.